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Sample records for miocene flood basalt

  1. Strawberry Rhyolites, Oregon: Northwestern extent of mid-Miocene flood basalt related rhyolites of the Pacific Northwest

    Science.gov (United States)

    Steiner, A. R.; Streck, M. J.

    2011-12-01

    Rhyolitic volcanism associated with the Columbia River-Steens flood basalts of the Pacific Northwest has traditionally been viewed to be centered at McDermitt caldera near the Oregon-Nevada border starting at ~16.5 Ma. In recent years, more rhyolitic centers along this latitude with ages between 16.5-15.5 Ma have been identified and associated with the inception of the Yellowstone hotspot. However the footprint of plume-head related rhyolites becomes much larger when silicic centers of mid-Miocene age in eastern Oregon are included extending the distribution of such rhyolites to areas near the towns of Baker City and John Day ~250 km north of McDermitt. This study addresses one of these rhyolitic centers that was virtually unknown and that constitutes the northwestern extent of mid-Miocene rhyolites. Rhyolites are centered ~40 km SSW of John Day and are considered part of the Strawberry Volcanic Field (SVF), which consists of a diverse group of volcanic rocks ranging from basalt to rhyolite with abundant intermediate compositions. One existing age date of 17.3 Ma ± 0.36 (Robyn, 1977) - if confirmed by our ongoing study - places these rhyolites at the very onset of plume-head related rhyolites. Strawberry rhyolitic lavas are most voluminous in the southwestern portion of the SVF covering approximately 500 km2 between Bear and Logan Valley. The rhyolitic lavas tend to be phenocryst-poor (LaN/YbN values ranging from 2.5 to 8.3 and higher values correlate positively with other differentiation indices (e.g. Ba, Sr, Eu/Eu*). Furthermore, major elements (e.g. SiO2 and FeO*) and trace elements (e.g. Ba, Sr, La, Zr/Hf) display common liquid lines of decent with Eu/Eu*. This suggests that the Strawberry Rhyolites are likely products of variable degrees of differentiation. Future petrogenetic evaluations will further investigate the origin of the Strawberry Rhyolites.

  2. Geology of the Mid-Miocene Rooster Comb Caldera and Lake Owyhee Volcanic Field, eastern Oregon: Silicic volcanism associated with Grande Ronde flood basalt

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    Benson, Thomas R.; Mahood, Gail A.

    2016-01-01

    The Lake Owyhee Volcanic Field (LOVF) of eastern Oregon consists of rhyolitic caldera centers and lava fields contemporaneous with and spatially related to Mid-Miocene Columbia River flood basalt volcanism. Previous studies delineated two calderas in the southeastern part of LOVF near Owyhee Reservoir, the result of eruptions of two ignimbrites, the Tuff of Leslie Gulch and the Tuff of Spring Creek. Our new interpretation is that these two map units are differentially altered parts of a single ignimbrite produced in a major phreatomagmatic eruption at 15.8 Ma. Areas previously mapped as Tuff of Spring Creek are locations where the ignimbrite contains abundant clinoptilolite ± mordenite, which made it susceptible to erosion. The resistant intracaldera Tuff of Leslie Gulch has an alteration assemblage of albite ± quartz, indicative of low-temperature hydrothermal alteration. Our new mapping of caldera lake sediments and pre- and post-caldera rhyolitic lavas and intrusions that are chemically similar to intracaldera Tuff of Leslie Gulch point to a single 20 × 25 km caldera, which we name the Rooster Comb Caldera. Erosion of the resurgently uplifted southern half of the caldera created dramatic exposures of intracaldera Tuff of Leslie Gulch cut by post-caldera rhyolite dikes and intrusions that are the deeper-level equivalents of lava domes and flows that erupted into the caldera lake preserved in exposures to the northeast. The Rooster Comb Caldera has features in common with more southerly Mid-Miocene calderas of the McDermitt Volcanic Field and High Rock Caldera Complex, including formation in a basinal setting shortly after flood basalt eruptions ceased in the region, and forming on eruption of peralkaline ignimbrite. The volcanism at Rooster Comb Caldera postdates the main activity at McDermitt and High Rock, but, like it, begins 300 ky after flood basalt volcanism begins in the area, and while flood basalts don't erupt through the silicic focus, are

  3. Assessing Eruption Column Height in Ancient Flood Basalt Eruptions

    Science.gov (United States)

    Glaze, Lori S.; Self, Stephen; Schmidt, Anja; Hunter, Stephen J.

    2015-01-01

    A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12-16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13-17 km for source widths of between 4-16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at approximately 45 deg N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the approximately 180 km of known Roza fissure length could have supported approximately 36 explosive events/phases, each with a duration of 3-4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (approximately 66 Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained

  4. Field-trip guide to Columbia River flood basalts, associated rhyolites, and diverse post-plume volcanism in eastern Oregon

    Science.gov (United States)

    Ferns, Mark L.; Streck, Martin J.; McClaughry, Jason D.

    2017-08-09

    The Miocene Columbia River Basalt Group (CRBG) is the youngest and best preserved continental flood basalt province on Earth, linked in space and time with a compositionally diverse succession of volcanic rocks that partially record the apparent emergence and passage of the Yellowstone plume head through eastern Oregon during the late Cenozoic. This compositionally diverse suite of volcanic rocks are considered part of the La Grande-Owyhee eruptive axis (LOEA), an approximately 300-kilometer-long (185 mile), north-northwest-trending, middle Miocene to Pliocene volcanic belt located along the eastern margin of the Columbia River flood basalt province. Volcanic rocks erupted from and preserved within the LOEA form an important regional stratigraphic link between the (1) flood basalt-dominated Columbia Plateau on the north, (2) bimodal basalt-rhyolite vent complexes of the Owyhee Plateau on the south, (3) bimodal basalt-rhyolite and time-transgressive rhyolitic volcanic fields of the Snake River Plain-Yellowstone Plateau, and (4) the High Lava Plains of central Oregon.This field-trip guide describes a 4-day geologic excursion that will explore the stratigraphic and geochemical relationships among mafic rocks of the Columbia River Basalt Group and coeval and compositionally diverse volcanic rocks associated with the early “Yellowstone track” and High Lava Plains in eastern Oregon. Beginning in Portland, the Day 1 log traverses the Columbia River gorge eastward to Baker City, focusing on prominent outcrops that reveal a distal succession of laterally extensive, large-volume tholeiitic flood lavas of the Grande Ronde, Wanapum, and Saddle Mountains Basalt formations of the CRBG. These “great flows” are typical of the well-studied flood basalt-dominated Columbia Plateau, where interbedded silicic and calc-alkaline lavas are conspicuously absent. The latter part of Day 1 will highlight exposures of middle to late Miocene silicic ash-flow tuffs, rhyolite domes, and

  5. On causal links between flood basalts and continental breakup

    Science.gov (United States)

    Courtillot, V.; Jaupart, C.; Manighetti, I.; Tapponnier, P.; Besse, J.

    1999-03-01

    Temporal coincidence between continental flood basalts and breakup has been noted for almost three decades. Eight major continental flood basalts have been produced over the last 300 Ma. The most recent, the Ethiopian traps, erupted in about 1 Myr at 30 Ma. Rifting in the Red Sea and Gulf of Aden, and possibly East African rift started at about the same time. A second trap-like episode occurred around 2 Ma and formation of true oceanic crust is due in the next few Myr. We find similar relationships for the 60 Ma Greenland traps and opening of the North Atlantic, 65 Ma Deccan traps and opening of the NW Indian Ocean, 132 Ma Parana traps and South Atlantic, 184 Ma Karoo traps and SW Indian Ocean, and 200 Ma Central Atlantic Margin flood basalts and opening of the Central Atlantic Ocean. The 250 Ma Siberian and 258 Ma Emeishan traps seem to correlate with major, if aborted, phases of rifting. Rifting asymmetry, apparent triple junctions and rift propagation (towards the flood basalt area) are common features that may, together with the relative timings of flood basalt, seaward dipping reflector and oceanic crust production, depend on a number of plume- and lithosphere- related factors. We propose a mixed scenario of `active/passive' rifting to account for these observations. In all cases, an active component (a plume and resulting flood basalt) is a pre-requisite for the breakup of a major oceanic basin. But rifting must be allowed by plate-boundary forces and is influenced by pre-existing heterogeneities in lithospheric structure. The best example is the Atlantic Ocean, whose large-scale geometry with three large basins was imposed by the impact points of three mantle plumes.

  6. Age of the youngest Palaeogene flood basalts in East Greenland

    DEFF Research Database (Denmark)

    Heilmann-Clausen, C.; Piasecki, Stefan; Abrahamsen, Niels

    2008-01-01

    results, this constrains the termination of the East Greenland Paleogene Igneous Province to the Early-Middle Eocene transition (nannoplankton chronozones NP13-NP14/earliest NP15). This is 6-8 Ma younger than according to previous biostratigraphic age assignments. The new data show that flood basalt...

  7. New Insights to the Mid Miocene Calc-alkaline Lavas of the Strawberry Volcanics, NE Oregon Surrounded by the Coeval Tholeiitic Columbia River Basalt Province

    Science.gov (United States)

    Steiner, A. R.; Streck, M. J.

    2013-12-01

    The Strawberry Volcanics (SV) of NE Oregon were distributed over 3,400 km2 during the mid-Miocene and comprise a diverse volcanic suite, which span the range of compositions from basalt to rhyolite. The predominant composition of this volcanic suite is calc-alkaline (CA) basaltic andesite and andesite, although tholeiitic (TH) lavas of basalt to andesite occur as well. The coeval flood basalts of the Columbia River province surround the SV. Here we will discuss new ages and geochemical data, and present a new geologic map and stratigraphy of the SV. The SV are emplaced on top of pre-Tertiary accreted terranes of the Blue Mountain Province, Mesozoic plutonic rocks, and older Tertiary volcanic rocks thought to be mostly Oligocene of age. Massive rhyolites (~300 m thick) are exposed mainly along the western flank and underlie the intermediate composition lavas. In the southern portion of this study area, alkali basaltic lavas, thought to be late Miocene to early Pliocene in age, erupted and overlie the SV. In addition, several regional ignimbrites reach into the area. The 9.7 Ma Devine Canyon Tuff and the 7.1 Ma Rattlesnake Tuff also overlie the SV. The 15.9-15.4 Ma Dinner Creek Tuff is mid-Miocene, and clear stratigraphic relationships are found in areas where the tuff is intercalated between thick SV lava flows. All of the basalts of the SV are TH and are dominated by phenocryst-poor (≤2%) lithologies. These basalts have an ophitic texture dominated by plagioclase, clinopyroxene and olivine (often weathered to iddingsite). Basalts and basaltic andesites have olivine Fo #'s ranging from 44 at the rims (where weathered to iddingsite) and as high as 88 at cores. Pyroxene Mg #'s range from 65 to 85. Andesites of the SV are sub-alkaline, and like the basalts, are exceedingly phenocryst-poor (≤3%) with microphenocrysts of plagioclase and lesser pyroxene and olivine, which occasionally occur as crystal clots of ~1-3 mm instead of single crystals. In addition, minimal

  8. Emplacement of Columbia River flood basalt

    Science.gov (United States)

    Reidel, Stephen P.

    1998-11-01

    Evidence is examined for the emplacement of the Umatilla, Wilbur Creek, and the Asotin Members of Columbia River Basalt Group. These flows erupted in the eastern part of the Columbia Plateau during the waning phases of volcanism. The Umatilla Member consists of two flows in the Lewiston basin area and southwestern Columbia Plateau. These flows mixed to form one flow in the central Columbia Plateau. The composition of the younger flow is preserved in the center and the composition of the older flow is at the top and bottom. There is a complete gradation between the two. Flows of the Wilbur Creek and Asotin Members erupted individually in the eastern Columbia Plateau and also mixed together in the central Columbia Plateau. Comparison of the emplacement patterns to intraflow structures and textures of the flows suggests that very little time elapsed between eruptions. In addition, the amount of crust that formed on the earlier flows prior to mixing also suggests rapid emplacement. Calculations of volumetric flow rates through constrictions in channels suggest emplacement times of weeks to months under fast laminar flow for all three members. A new model for the emplacement of Columbia River Basalt Group flows is proposed that suggests rapid eruption and emplacement for the main part of the flow and slower emplacement along the margins as the of the flow margin expands.

  9. Shallow Miocene basaltic magma reservoirs in the Bahia de Los Angeles basin, Baja California, Mexico

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    Delgado-Argote, Luis A.; García-Abdeslem, Juan

    1999-01-01

    The basement in the Bahía de Los Angeles basin consists of Paleozoic metamorphic rocks and Cretaceous granitoids. The Neogene stratigraphy overlying the basement is formed, from the base to the top, by andesitic lava flows and plugs, sandstone and conglomeratic horizons, and Miocene pyroclastic flow units and basaltic flows. Basaltic dikes also intrude the whole section. To further define its structure, a detailed gravimetric survey was conducted across the basin about 1 km north of the Sierra Las Flores. In spite of the rough and lineal topography along the foothills of the Sierra La Libertad, we found no evidence for large-scale faulting. Gravity data indicates that the basin has a maximum depth of 120 m in the Valle Las Tinajas and averages 75 m along the gravimetric profile. High density bodies below the northern part of the Sierra Las Flores and Valle Las Tinajas are interpreted to be part of basaltic dikes. The intrusive body located north of the Sierra Las Flores is 2.5 km wide and its top is about 500 m deep. The lava flows of the top of the Sierra Las Flores, together with the distribution of basaltic activity north of this sierra, suggests that this intrusive body continues for 20 km along a NNW-trending strike. Between the sierras Las Flores and Las Animas, a 0.5-km-wide, 300-m-thick intrusive body is interpreted at a depth of about 100 m. This dike could be part of the basaltic activity of the Cerro Las Tinajas and the small mounds along the foothills of western Sierra Las Animas. The observed local normal faulting in the basin is inferred to be mostly associated with the emplacement of the shallow magma reservoirs below Las Flores and Las Tinajas.

  10. Miocene Basaltic Lava Flows and Dikes of the Intervening Area Between Picture Gorge and Steens Basalt of the CRBG, Eastern Oregon

    Science.gov (United States)

    Cahoon, E. B.; Streck, M. J.

    2016-12-01

    Mid-Miocene basaltic lavas and dikes are exposed in the area between the southern extent of the Picture Gorge Basalt (PGB) and the northern extent of Steens Basalt in a wide corridor of the Malheur National Forest, eastern Oregon. An approximate mid-Miocene age of sampled basaltic units is indicated by stratigraphic relationships to the 16 Ma Dinner Creek Tuff. Lavas provide an opportunity to extend and/or revise distribution areas of either CRBG unit and explore the petrologic transition between them. The PGB and the Steens Basalt largely represent geochemically distinct tholeiitic units of the CRBG; although each unit displays internal complexity. Lavas of PGB are relatively primitive (MgO 5-9 wt.%) while Steens Basalt ranges in MgO from >9 to 3 wt.% but both units are commonly coarsely porphyritic. Conversely, Steens Basalt compositions are on average more enriched in highly incompatible elements (e.g. Rb, Th) and relatively enriched in the lesser incompatible elements (e.g. Y, Yb) compared to the Picture Gorge basalts. These compositional signatures produce inclined and flat patterns on mantle-normalized incompatible trace element plots but with similar troughs and spikes, respectively. New compositional data from our study area indicate basaltic lavas can be assigned as PGB lava flows and dikes, and also to a compositional group chemically distinct between Steens Basalt and PGB. Distribution of lava flows with PGB composition extend this CRBG unit significantly south/southeast closing the exposure gap between PGB and Steens Basalt. We await data that match Steens Basalt compositions but basaltic lavas with petrographic features akin to Steens Basalt have been identified in the study area. Lavas of the transitional unit share characteristics with Upper Steens and Picture Gorge basalt types, but identify a new seemingly unique composition. This composition is slightly more depleted in the lesser incompatible elements (i.e. steeper pattern) on mantle normalized

  11. High water content in primitive continental flood basalts.

    Science.gov (United States)

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-05-04

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  12. Sulfur degassing due to contact metamorphism during flood basalt eruptions

    Science.gov (United States)

    Yallup, Christine; Edmonds, Marie; Turchyn, Alexandra V.

    2013-11-01

    We present a study aimed at quantifying the potential for generating sulfur-rich gas emissions from the devolatilization of sediments accompanying sill emplacement during flood basalt eruptions. The potential contribution of sulfur-rich gases from sediments might augment substantially the magma-derived sulfur gases and hence impact regional and global climate. We demonstrate, from a detailed outcrop-scale study, that sulfur and total organic carbon have been devolatilized from shales immediately surrounding a 3-m thick dolerite sill on the Isle of Skye, Scotland. Localized partial melting occurred within a few centimetres of the contact in the shale, generating melt-filled cracks. Pyrite decomposed on heating within 80 cm of the contact, generating sulfur-rich gases (a mixture of H2S and SO2) and pyrrhotite. The pyrrhotite shows 32S enrichment, due to loss of 34S-enriched SO2. Further decomposition and oxidation of pyrrhotite resulted in hematite and/or magnetite within a few cm of the contact. Iron sulfates were produced during retrogressive cooling and oxidation within 20 cm of the contact. Decarbonation of the sediments due to heating is also observed, particularly along the upper contact of the sill, where increasing δ13C is consistent with loss of methane gas. The geochemical and mineralogical features observed in the shales are consistent with a short-lived intrusion, emplaced in desulfurization, as well as decarbonation, of shales adjacent to an igneous intrusion. The liberated fluids, rich in sulfur and carbon, are likely to be focused along regions of low pore fluid pressure along the margins of the sill. The sulfur gases liberated from the sediments would have augmented the sulfur dioxide (and hydrogen sulfide) yield of the eruption substantially, had they reached the surface. This enhancement of the magmatic sulfur budget has important implications for the climate impact of large flood basalt eruptions that erupt through thick, volatile-rich sedimentary

  13. Miocene

    Indian Academy of Sciences (India)

    (Malvaceae s.l.), is described from the Sindhudurg Formation. (Miocene) at the ... described along with palynofossils (Phadtare and. Kulkarni 1980a ... D istrict,. Maharash tra,. India, star indicates fossil lo cality; and. ( b. ) litholog o f the. Kalviw adi .... Following collision of the two plates, land connections ... The occur- rence of ...

  14. Architecture and emplacement of flood basalt flow fields: case studies from the Columbia River Basalt Group, NW USA

    Science.gov (United States)

    Vye-Brown, C.; Self, S.; Barry, T. L.

    2013-03-01

    The physical features and morphologies of collections of lava bodies emplaced during single eruptions (known as flow fields) can be used to understand flood basalt emplacement mechanisms. Characteristics and internal features of lava lobes and whole flow field morphologies result from the forward propagation, radial spread, and cooling of individual lobes and are used as a tool to understand the architecture of extensive flood basalt lavas. The features of three flood basalt flow fields from the Columbia River Basalt Group are presented, including the Palouse Falls flow field, a small (8,890 km2, ˜190 km3) unit by common flood basalt proportions, and visualized in three dimensions. The architecture of the Palouse Falls flow field is compared to the complex Ginkgo and more extensive Sand Hollow flow fields to investigate the degree to which simple emplacement models represent the style, as well as the spatial and temporal developments, of flow fields. Evidence from each flow field supports emplacement by inflation as the predominant mechanism producing thick lobes. Inflation enables existing lobes to transmit lava to form new lobes, thus extending the advance and spread of lava flow fields. Minimum emplacement timescales calculated for each flow field are 19.3 years for Palouse Falls, 8.3 years for Ginkgo, and 16.9 years for Sand Hollow. Simple flow fields can be traced from vent to distal areas and an emplacement sequence visualized, but those with multiple-layered lobes present a degree of complexity that make lava pathways and emplacement sequences more difficult to identify.

  15. Sulfur release from the Columbia River Basalts and other flood lava eruptions constrained by a model of sulfide saturation

    Science.gov (United States)

    Blake, S.; Self, S.; Sharma, K.; Sephton, S.

    2010-11-01

    A very likely cause of widespread environmental impacts of flood basalt eruptions is the emission of sulfur, chlorine, and possibly fluorine from the erupting magma. We present new data on the S contents of rare glass inclusions and matrix glasses preserved in quenched lava selvages from lava fields of the Columbia River Basalt Group (CRBG; Ginkgo, Sand Hollow and Sentinel Gap flows, Wanapum Basalt Formation). We compare these results with published data from Neral and Jawar Formation lavas (Deccan Traps, India) and the Roza flow (CRBG). CRBG glass inclusions have up to 2000 ppm S and 15-16 wt.% FeO total. By contrast, the Deccan examples have about 1400 ppm S and 10 wt.% FeO total. Several of the glass inclusions are partly degassed, indicating entrapment during magma rise, and matrix glasses are typically more evolved than glass inclusions due to small amounts of in situ crystallization. Using only the highest S inclusions and taking account of the effect of in situ crystallization and degassing on the S content of the residual matrix glasses indicates S yields of about 0.07 to 0.1 wt.% from Deccan eruptions and about 0.15 wt.% from Wanapum (CRBG) eruptions. The pre-eruptive S contents of these magmas correlate with weight% FeO total in the same way as undegassed sulfide-saturated mid-ocean ridge basalts. Using oceanic basalts to define a sulfide saturation line, and data on S contents of degassed basalts, we propose an equation to estimate the weight% S yield (ΔS) from initially sulfide-saturated basalt liquid without the need to find well-preserved, rare, undegassed glass inclusions and matrix glasses: ΔS=(0.01418×FeO-0.06381)±0.02635. This compares well with independent estimates derived from the petrologic method by taking the difference in S concentration of glass inclusions and matrix glass. Applying our method to the aphyric Grande Ronde Basalts of the CRBG implies a total yield of about 1000 Gt SO 2 delivered into the Miocene atmosphere in

  16. Growing magma chambers control the distribution of small-scale flood basalts.

    Science.gov (United States)

    Yu, Xun; Chen, Li-Hui; Zeng, Gang

    2015-11-19

    Small-scale continental flood basalts are a global phenomenon characterized by regular spatio-temporal distributions. However, no genetic mechanism has been proposed to explain the visible but overlooked distribution patterns of these continental basaltic volcanism. Here we present a case study from eastern China, combining major and trace element analyses with Ar-Ar and K-Ar dating to show that the spatio-temporal distribution of small-scale flood basalts is controlled by the growth of long-lived magma chambers. Evolved basalts (SiO2 > 47.5 wt.%) from Xinchang-Shengzhou, a small-scale Cenozoic flood basalt field in Zhejiang province, eastern China, show a northward younging trend over the period 9.4-3.0 Ma. With northward migration, the magmas evolved only slightly ((Na2O + K2O)/MgO = 0.40-0.66; TiO2/MgO = 0.23-0.35) during about 6 Myr (9.4-3.3 Ma). When the flood basalts reached the northern end of the province, the magmas evolved rapidly (3.3-3.0 Ma) through a broad range of compositions ((Na2O + K2O)/MgO = 0.60-1.28; TiO2/MgO = 0.30-0.57). The distribution and two-stage compositional evolution of the migrating flood basalts record continuous magma replenishment that buffered against magmatic evolution and induced magma chamber growth. Our results demonstrate that the magma replenishment-magma chamber growth model explains the spatio-temporal distribution of small-scale flood basalts.

  17. Seeking a paleontological signature for mass extinctions caused by flood basalt eruptions

    Science.gov (United States)

    Payne, J.; Bush, A. M.; Chang, E. T.; Heim, N. A.; Knope, M. L.; Pruss, S. B.

    2016-12-01

    Flood basalt eruptions coincide with numerous extinction events in the fossil record. Increasingly precise absolute age determinations for both the timing of eruption and of species extinctions have strengthened the case for flood basalt eruptions as the single most important trigger for major mass extinction events in the fossil record. However, the extent to which flood basalt eruptions cause a pattern of biotic loss distinctive from extinctions triggered by other geological or biological processes remains an open question. In the absence of diagnostic mapping between geological triggers and biological losses, establishing the identities of causal agents for mass extinctions will continue to depend primarily on evidence for temporal coincidence. Here we use a synoptic database of marine animal genera spanning the Phanerozoic, including times of first and last occurrence, body size, motility, life position, feeding mode, and respiratory physiology to assess whether extinction events temporally associated with flood basalt eruptions exhibit a diagnostic pattern of extinction selectivity. We further ask whether any events not associated with known large igneous provinces nevertheless display extinction patterns suggestive of such a cause. Finally, we ask whether extinction events associated with other primary causes, such as glaciation or bolide impact, are distinguishable from events apparently triggered by flood basalt eruptions on the basis of extinction selectivity patterns

  18. Pb isotope evidence for contributions from different Iceland mantle components to Palaeogene East Greenland flood basalts

    DEFF Research Database (Denmark)

    Peate, David; Stecher, Ole

    2003-01-01

    We present new Pb isotope data on 21 samples of break-up-related flood basalts (56–54 Ma) from the Blosseville Kyst region of East Greenland. These samples show a considerable range in isotopic composition (206Pb/204Pb 17.6 to 19.3) that broadly correlates with compositional type. The ‘low-Ti’ type...... in the selected samples. Uncontaminated Palaeogene East Greenland flood basalts appear to have sampled the same broad range in mantle compositions seen in Recent Iceland basalts. In contrast to the peripheral lava suites from the British Isles and Southeast Greenland, where the inferred uncontaminated magmas have...... to the most radiogenic values found in recent Icelandic basalts. Furthermore, the main volume of lavas in East Greenland is displaced away from the NAEM towards this radiogenic Pb component. Thus, this ‘Iceland radiogenic Pb end-member’ component was a significant contributor to the break-up-related magmatism...

  19. Selective environmental stress from sulphur emitted by continental flood basalt eruptions

    Science.gov (United States)

    Schmidt, Anja; Skeffington, Richard; Thordarson, Thorvaldur; Self, Stephen; Forster, Piers; Rap, Alexandru; Ridgwell, Andy; Fowler, David; Wilson, Marjorie; Mann, Graham; Wignall, Paul; Carslaw, Ken

    2016-04-01

    Several biotic crises during the past 300 million years have been linked to episodes of continental flood basalt volcanism, and in particular to the release of massive quantities of magmatic sulphur gas species. Flood basalt provinces were typically formed by numerous individual eruptions, each lasting years to decades. However, the environmental impact of these eruptions may have been limited by the occurrence of quiescent periods that lasted hundreds to thousands of years. Here we use a global aerosol model to quantify the sulphur-induced environmental effects of individual, decade-long flood basalt eruptions representative of the Columbia River Basalt Group, 16.5-14.5 million years ago, and the Deccan Traps, 65 million years ago. For a decade-long eruption of Deccan scale, we calculate a decadal-mean reduction in global surface temperature of 4.5 K, which would recover within 50 years after an eruption ceased unless climate feedbacks were very different in deep-time climates. Acid mists and fogs could have caused immediate damage to vegetation in some regions, but acid-sensitive land and marine ecosystems were well-buffered against volcanic sulphur deposition effects even during century-long eruptions. We conclude that magmatic sulphur from flood basalt eruptions would have caused a biotic crisis only if eruption frequencies and lava discharge rates had been high and sustained for several centuries at a time.

  20. From initiation to termination: a petrostratigraphic tour of the Ethiopian Low-Ti Flood Basalt Province

    Science.gov (United States)

    Krans, S. R.; Rooney, T. O.; Kappelman, J.; Yirgu, G.; Ayalew, D.

    2018-05-01

    Continental flood basalts (CFBs), thought to preserve the magmatic record of an impinging mantle plume head, offer spatial and temporal insights into melt generation processes in large igneous provinces (LIPs). Despite the utility of CFBs in probing mantle plume composition, these basalts typically erupt fractionated compositions, suggestive of significant residence time in the continental lithosphere. The location and duration of residence within the lithosphere provide additional insights into the flux of plume-related magmas. The NW Ethiopian plateau offers a well-preserved stratigraphic sequence from flood basalt initiation to termination, and is thus an important target for study of CFBs. This study examines modal observations within a stratigraphic framework and places these observations within the context of the magmatic evolution of the Ethiopian CFB province. Data demonstrate multiple pulses of magma recharge punctuated by brief shut-down events, with initial flows fed by magmas that experienced deeper fractionation (lower crust). Broad changes in modal mineralogy and flow cyclicity are consistent with fluctuating changes in magmatic flux through a complex plumbing system, indicating pulsed magma flux and an overall shallowing of the magmatic plumbing system over time. The composition of plagioclase megacrysts suggests a constant replenishing of new primitive magma recharging the shallow plumbing system during the main phase of volcanism, reaching an apex prior to flood basalt termination. The petrostratigraphic data sets presented in this paper provide new insight into the evolution of a magma plumbing system in a CFB province.

  1. Life and Death of a Flood Basalt: Evolution of a Magma Plumbing System in the Ethiopian Low-Ti Flood Basalt Province

    Science.gov (United States)

    Krans, S. R.; Rooney, T. O.; Kappelman, J. W.; Yirgu, G.; Ayalew, D.

    2017-12-01

    Continental flood basalt provinces (CFBPs), which are thought to preserve the magmatic record of an impinging mantle plume head, offer spatial and temporal insight into melt generation processes in Large Igneous Provinces (LIPs). Despite the utility of CFBPs in probing the composition of mantle plumes, these basalts typically erupt fractionated compositions, suggestive of significant residence time in the continental lithosphere. The location and duration of this residence within the continental lithosphere provides additional insights into the flux of plume-related magmas. The NW Ethiopian plateau offers a well preserved stratigraphic section from flood basalt initiation to termination, and is thus an important target for study of CFBPs. We examine petrographic and whole rock geochemical variation within a stratigraphic framework and place these observations within the context of the magmatic evolution of the Ethiopian CFBP. We observe multiple pulses of magma recharge punctuated by brief shut-down events and an overall shallowing of the magmatic plumbing system over time. Initial flows are fed by magmas that have experienced deeper fractionation (clinopyroxene dominated and lower CaO/Al2O3 for a given MgO value), likely near the crust-mantle boundary. Subsequent flows are fed by magmas that have experienced shallower fractionation (plagioclase dominated and higher CaO/Al2O3 for a given MgO value) in addition to deeper fractionated magmas. Broad changes in flow thickness and modal mineralogy are consistent with fluctuating changes in magmatic flux through a complex plumbing system and indicate pulsed magma flux and an overall shallowing of the magmatic plumbing system over time. Pulses of less differentiated magmas (MgO > 8 wt%) and high-An composition of plagioclase megacrysts (labradorite to bytownite) suggest a constant replenishing of new primitive magma recharging the shallow plumbing system during the main phase of flood volcanism, though the magnitude of

  2. Release of Volatiles During North Atlantic Flood Basalt Volcanism and Correlation to the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Pedersen, J. M.; Tegner, C.; Kent, A. J.; Ulrich, T.

    2017-12-01

    The opening of the North Atlantic Ocean between Greenland and Norway during the lower Tertiary led to intense flood basalt volcanism and the emplacement of the North Atlantic Igneous Province (NAIP). The volcanism is temporally overlapping with the Paleocene-Eocene Thermal Maximum (PETM), but ash stratigraphy and geochronology suggests that the main flood basalt sequence in East Greenland postdates the PETM. Significant environmental changes during the PETM have been attributed to the release of CO2 or methane gas due to either extensive melting of hydrates at the ocean floor or as a consequence of the interaction of mantle derived magmas with carbon rich sediments.Estimates suggest that a minimum of 1.8x106 km3 of basaltic lava erupted during North Atlantic flood basalt volcanism. Based on measurements of melt inclusions from the flood basalts our preliminary calculations suggest that approximately 2300 Gt of SO2 and 600 Gt of HCl were released into the atmosphere. Calculated yearly fluxes approach 23 Mt/y SO2 and 6 Mt/y HCl. These estimates are regarded as conservative.The S released into to the atmosphere during flood basalt volcanism can form acid aerosols that absorb and reflect solar radiation, causing an effective cooling effect. The climatic effects of the release of Cl into the atmosphere are not well constrained, but may be an important factor for extinction scenarios due to destruction of the ozone layer.The climatic changes due to the release of S and Cl in these amounts, and for periods extending for hundred thousand of years, although not yet fully constrained are likely to be significant. One consequence of the North Atlantic flood basalt volcanism may have been the initiation of global cooling to end the PETM.

  3. Duration of Parana magmatism and implications for the evolution and source regions of continental flood basalts

    International Nuclear Information System (INIS)

    Mantovani, M.S.M.; Stewart, K.; Turner, S.; Hawkesworth, C.J.

    1995-01-01

    Duration of Continental Floods Basalts magmatism has generally been considered to be extremely short. Ar-Ar data for different magma type, over a broad region within Parana, demonstrate a duration of 10 Ma, an order of magnitude greater than the usually accepted duration of magmatism. The dating method included rigorous geochemical selection tests, to discard altered samples, combined with the analysis of laser spot technique using the isochron approach. This methodology allows discrimination between rocks which yield precise ages and those which are too altered or heterogeneous. The agreement between the determined age and the relative stratigraphic position of samples supports the above statement. 4 figs

  4. Duration of Parana magmatism and implications for the evolution and source regions of continental flood basalts

    Energy Technology Data Exchange (ETDEWEB)

    Mantovani, M.S.M. [Sao Paulo Univ., SP (Brazil). Inst. Astronomico e Geofisico; Stewart, K.; Turner, S.; Hawkesworth, C.J. [Open Univ., Milton Keynes (United Kingdom). Dept. of Earth Sciences

    1995-12-31

    Duration of Continental Floods Basalts magmatism has generally been considered to be extremely short. Ar-Ar data for different magma type, over a broad region within Parana, demonstrate a duration of 10 Ma, an order of magnitude greater than the usually accepted duration of magmatism. The dating method included rigorous geochemical selection tests, to discard altered samples, combined with the analysis of laser spot technique using the isochron approach. This methodology allows discrimination between rocks which yield precise ages and those which are too altered or heterogeneous. The agreement between the determined age and the relative stratigraphic position of samples supports the above statement. 4 figs.

  5. Changes in Pacific Absolute Plate Motion and Formation of Oceanic Flood Basalt Plateaus

    Science.gov (United States)

    Kroenke, L. W.; Wessel, P.

    2006-12-01

    The origin of the large oceanic flood basalt plateaus that are prominent features of the central western Pacific Basin remains unclear. Major changes in Pacific Absolute Plate Motion (APM) have been identified as occurring at 145, 125, 96, and 47 Ma. Formation of the Shatsky Rise (~145 Ma), the Ontong Java Plateau (122+ Ma), the Southern Hess Rise (95±5 Ma), and the Louisiade Plateau (~48 Ma) appear to coincide with these changes. A smaller, but still prominent change in Pacific APM also occurred at 110 Ma when the Northern Hess Rise formed. Although these concurrent events may simply be chance occurrences, initiation of plate tectonic reorganizations upon arrival of mantle plume heads also was proposed by Ratcliff et al. (1998), who suggested that the mantle plume head delivery of hot material to produce flood basalts also had the potential to trigger reorganizations of plate motions. It should be noted, however, that Pacific Rim subduction zone development also coincides with these APM changes, and that the actual cause and effect of each change in APM has yet to be clearly established. Here we present a modified Pacific APM model that uses several older seamount chains (Musicians, Ratak-Gilbert-Ellice, the Wake trails, and the Liliuokalani trails) to constrain the oldest Pacific plate motion using the hybrid technique of Wessel et al (2006).

  6. Physical Volcanological and Petrogenetic Implications of Intra-lava Flow Geochemical Heterogeneity in the Columbia River Flood Basalt Province, USA.

    Science.gov (United States)

    Vye, C. L.; Barry, T. L.; Self, S.; Gannoun, A.; Burton, K. W.

    2007-12-01

    Continental flood basalt lava flows are widely assumed to represent compositionally uniform and rapidly erupted products of large well-mixed magma reservoirs. However, this study presents new data to illustrate systematic element and isotope variations within the flow field formed by an individual flood basalt eruption, both vertically within each sheet lobe and laterally between the constituent lobes. Such variation is significant in chemostratigraphic correlation of flood basalt lava units, in identifying source variability during one eruption, and in petrogenetic modeling. We investigate the extent and cause of compositional variation through tracing lava sheet lobes in a 2,660 cubic kilometer pahoehoe flow field formed during a single eruption in the Columbia River Basalt Province, USA. This is based on features related to emplacement by the inflation mechanism. This method of emplacement is supported by small but statistically significant and systematic major and trace element variation e.g. MgO 3.09- 4.55 wt%, Ni 17.5-25.6 ppm, indicative of fractional crystallisation. Re-Os isotopes indicate progressive crustal contamination of the magma over the timescale of a single flood basalt eruption. By establishing this physical volcanological framework, we determine a temporal link with the supply of lava from the vent(s) and apply it to investigate sequential magmatic evolution during the timescale of one eruption.

  7. The source and longevity of sulfur in an Icelandic flood basalt eruption plume

    Science.gov (United States)

    Ilyinskaya, Evgenia; Edmonds, Marie; Mather, Tamsin; Schmidt, Anja; Hartley, Margaret; Oppenheimer, Clive; Pope, Francis; Donovan, Amy; Sigmarsson, Olgeir; Maclennan, John; Shorttle, Oliver; Francis, Peter; Bergsson, Baldur; Barsotti, Sara; Thordarson, Thorvaldur; Bali, Eniko; Keller, Nicole; Stefansson, Andri

    2015-04-01

    The Holuhraun fissure eruption (Bárðarbunga volcanic system, central Iceland) has been ongoing since 31 August 2014 and is now the largest in Europe since the 1783-84 Laki event. For the first time in the modern age we have the opportunity to study at first hand the environmental impact of a flood basalt fissure eruption (>1 km3 lava). Flood basalt eruptions are one of the most hazardous volcanic scenarios in Iceland and have had enormous societal and economic consequences across the northern hemisphere in the past. The Laki eruption caused the deaths of >20% of the Icelandic population by environmental pollution and famine and potentially also increased European levels of mortality through air pollution by sulphur-bearing gas and aerosol. A flood basalt eruption was included in the UK National Risk Register in 2012 as one of the highest priority risks. The gas emissions from Holuhraun have been sustained since its beginning, repeatedly causing severe air pollution in populated areas in Iceland. During 18-22 September, SO2 fluxes reached 45 kt/day, a rate of outgassing rarely observed during sustained eruptions, suggesting that the sulfur loading per kg of erupted magma exceeds both that of other recent eruptions in Iceland and perhaps also other historic basaltic eruptions globally. This raises key questions regarding the origin of these prodigious quantities of sulphur. A lack of understanding of the source of this sulfur, the conversion rates of SO2 gas into aerosol, the residence times of aerosol in the plume and the dependence of these on meteorological factors is limiting our confidence in the ability of atmospheric models to forecast gas and aerosol concentrations in the near- and far-field from Icelandic flood basalt eruptions. In 2015 our group is undertaking a project funded by UK NERC urgency scheme to investigate several aspects of the sulfur budget at Holuhraun using a novel and powerful approach involving simultaneous tracking of sulfur and

  8. Rate of deformation in the Pasco Basin during the Miocene as determined by distribution of Columbia River basalt flows

    International Nuclear Information System (INIS)

    Reidel, S.P.; Ledgerwood, R.K.; Myers, C.W.; Jones, M.G.; Landon, R.D.

    1980-03-01

    Detailed mapping of over 8000 square kilometers and logs from 20 core holes were used to determine the distribution and thickness of basalt flows and interbeds in the Pasco Basin. The data indicate the high-MgO Grande Ronde Basalt and Wanapum Basalt thicken from the northeast to the southwest. Deformation began in late Frenchman Springs time in the Saddle Mountains along a northwest-southeast trend and in Roza time along an east-west trend. By late Wanapum time, basalt flows were more restricted on the east side. Saddle Mountains Basalt flows spread out in the basin from narrow channels to the east. The Umatilla Member entered from the southeast and is confined to the south-central basin, while the Wilbur Creek, Asotin, Esquatzel, Pomona, and Elephant Mountain Members entered from the east and northeast. The distribution of these members is controlled by flow volume, boundaries of other flows, and developing ridges. The Wilbur Creek, Asotin, and Esquatzel flows exited from the basin in a channel along the northern margin of the Umatilla flow, while the Pomona and Elephant Mountain flows exited between Umtanum Ridge and Wallula Gap. The thickness of sedimentary interbeds and basalt flows indicated subsidence and/or uplift began in post-Grande Ronde time (14.5 million years before present) and continued through Saddle Mountains time (10.5 million years before present). Maximum subsidence occurred 40 kilometers (24 miles) north of Richland, Washington with an approximate rate of 25 meters (81 feet) per million years during the eruption of the basalt. Maximum uplift along the developing ridges was 70 meters (230 feet) per million years

  9. Earth's evolving subcontinental lithospheric mantle: inferences from LIP continental flood basalt geochemistry

    Science.gov (United States)

    Greenough, John D.; McDivitt, Jordan A.

    2018-04-01

    Archean and Proterozoic subcontinental lithospheric mantle (SLM) is compared using 83 similarly incompatible element ratios (SIER; minimally affected by % melting or differentiation, e.g., Rb/Ba, Nb/Pb, Ti/Y) for >3700 basalts from ten continental flood basalt (CFB) provinces representing nine large igneous provinces (LIPs). Nine transition metals (TM; Fe, Mn, Sc, V, Cr, Co, Ni, Cu, Zn) in 102 primitive basalts (Mg# = 0.69-0.72) from nine provinces yield additional SLM information. An iterative evaluation of SIER values indicates that, regardless of age, CFB transecting Archean lithosphere are enriched in Rb, K, Pb, Th and heavy REE(?); whereas P, Ti, Nb, Ta and light REE(?) are higher in Proterozoic-and-younger SLM sources. This suggests efficient transfer of alkali metals and Pb to the continental lithosphere perhaps in association with melting of subducted ocean floor to form Archean tonalite-trondhjemite-granodiorite terranes. Titanium, Nb and Ta were not efficiently transferred, perhaps due to the stabilization of oxide phases (e.g., rutile or ilmenite) in down-going Archean slabs. CFB transecting Archean lithosphere have EM1-like SIER that are more extreme than seen in oceanic island basalts (OIB) suggesting an Archean SLM origin for OIB-enriched mantle 1 (EM1). In contrast, OIB high U/Pb (HIMU) sources have more extreme SIER than seen in CFB provinces. HIMU may represent subduction-processed ocean floor recycled directly to the convecting mantle, but to avoid convective homogenization and produce its unique Pb isotopic signature may require long-term isolation and incubation in SLM. Based on all TM, CFB transecting Proterozoic lithosphere are distinct from those cutting Archean lithosphere. There is a tendency for lower Sc, Cr, Ni and Cu, and higher Zn, in the sources for Archean-cutting CFB and EM1 OIB, than Proterozoic-cutting CFB and HIMU OIB. All CFB have SiO2 (pressure proxy)-Nb/Y (% melting proxy) relationships supporting low pressure, high % melting

  10. 87Sr/86Sr variations in basalts of Late Eocene-Early Miocene series in Eastern Sikhoteh-Alin

    International Nuclear Information System (INIS)

    Esin, S.V.; Ponomarchuk, V.A.; Shipitsyn, Yu.G.; Palesskij, Yu.G.

    1993-01-01

    Late Eocene high-alumina and Oligocene high-alumina and magnesian basalts of the Neogene calc-alkaline series from the Eastern Sikhoteh-Alin are shown to have the following 87 Sr/ 86 Sr ratios: 0.70390-0.70465; 0.70347-0.70401, and the 0.70330-0.70347. Analysis of variations of Sr ratios, REE, HFSE, and LILE suggests that they are the products of successive melting of a multicomponent source containing the peridotite material of OIB- and MORB-types altered by fluids to a different degree and the pelagic sediments

  11. Hf-Nd Isotopic Correlation in the Deccan Flood Basalt Province

    Science.gov (United States)

    Saha, A.; Basu, A. R.; Barling, J.; Anbar, A. D.; Hooper, P. R.

    2001-12-01

    Hafnium isotopes along with other isotopic and geochemical characteristics, including incompatible trace elements, of several of the lower formations of the Deccan Flood Basalt Province were analyzed to characterize petrogenesis of different tholeiitic lava suites, especially with respect to potential mantle and crustal sources. The rare earth elements of the different formations (from top to bottom- Mahabaleshwar, Ambenali, Bushe, Khandala and Neral) all show an LREE-enriched signature, concentrations varying between 30 to 60 times chondrite for La. (La/Lu)n values range from 4.1 to above 8 with the exception of Ambenali, which has a less LREE-enriched signature with (La/Lu)n values ranging between 3.6 to 5.3. Hafnium isotopic data of the lower formations of the Deccan show initial \\epsilonHf(T) values covering a range from -3 to -28. 176Lu/177Hf varies between 0.20 to 0.70. f(Lu/Hf) varies within a narrow range, between -0.90 to -0.97 while f(Sm/Nd) ranges from -0.84 to -0.86. Bushe gives the lowest range of \\epsilonHf(T) from -21 to -28 with the corresponding \\epsilonNd(T) varying between -4.0 and -16.9, while Khandala for almost the same range of neodymium isotopic values has \\epsilonHf(T) between -11 and -15. The \\epsilonHf(T) values of Neral is in between those of Khandala and Bushe, around -19. Ambenali, has the narrowest range with \\epsilonHf(T) of -3 and \\epsilonNd(T) between 3 and 5. The Ambenali suite reflects the least contaminated of the Deccan suite of lavas as analyzed here and previously confirmed by other isotopic studies. In Hf-Nd isotope correlation plot, the lower Deccan formations of Neral, Khandala and Bushe define individual subparallel arrays that are shallower than the oceanic basalt array and the overall terrestrial array, including the crustal array, although the bulk of the lower formation data fall within the crustal array of Vervoort et al (1999). From these subparallel Hf-Nd arrays, it is evident that the other end

  12. Changing compositions in the Iceland plume; Isotopic and elemental constraints from the Paleogene Faroe flood basalts

    DEFF Research Database (Denmark)

    Søager, Nina; Holm, Paul Martin

    2011-01-01

    Elemental and Sr, Nd, Hf and high precision Pb isotopic data are presented from 59 low-Ti and high-Ti lavas from the syn-break up part of the Faroe Flood Basalt Province. The depleted MORB-like low-Ti lavas erupted in the rift zone between the Faroe Islands and central East Greenland around......-type component similar in geochemistry to the Icelandic Öræfajökull lavas. This component is believed to be recycled pelagic sediments in the plume but it can alternatively be a local crustal or lithospheric mantle component. The enriched Faroe high-Ti lavas erupted inland from the rift have isotopic...... compositions very similar to the enriched Icelandic neo-volcanics and these lava suites apparently share the two enriched plume end-members IE1 and IE2 (Geochim. Cosmochim. Acta 68, 2, 2004). The lack of mixing between high and low-Ti melts at the time of break up, is explained by a zoned plume where only low...

  13. Submarine Flood Basalt Eruptions and Flows of Ontong Java Plateau, Nauru Basin and East Mariana Basin

    Science.gov (United States)

    Michael, P. J.; Trowbridge, S. R.; Zhang, J.; Johnson, A. L.

    2016-12-01

    water over gentle slopes (0.1-0.5°). The presence of many glass layers within the cores contrasts with continental flood basalts and suggests the flows were covered by a thick, moving, shifting carapace of solidified lava. They may represent an extreme form of inflated pahoehoe flows. 1 Michael, P.J., 1999 G-Cubed 1 (12), GC000025 2 Roberge J., et al., 2005, Geology 33, 501-504

  14. Osmium isotope variations accompanying the eruption of a single lava flow field in the Columbia River Flood Basalt Province

    Science.gov (United States)

    Vye-Brown, C.; Gannoun, A.; Barry, T. L.; Self, S.; Burton, K. W.

    2013-04-01

    Geochemical interpretations of continental flood basalts usually assume that individual lava flows represent compositionally homogenous and rapidly erupted products of large well-mixed magma reservoirs. However, inflated pāhoehoe lavas may develop over considerable periods of time and preserve chemical variations that can be temporally linked through flow formation to eruption sequence thus providing an understanding of magma evolution over the timescale of a single eruption. This study presents comprehensive major, trace element and Re-Os isotope data for a single eruption that formed the 2660 km3 Sand Hollow flow field in the Columbia River Basalt Province, USA. Major and trace element variations accompanying flow emplacement (e.g. MgO 3.09-4.55 wt%, Ni 17.5-25.6 ppm) are consistent with fractional crystallisation, but other petrogenetic processes or variable sources cannot be distinguished. However, there is a systematic shift in the initial 187Os/188Os isotope composition of the magma (age corrected to 15.27 Ma), from 0.174 (lava core) to 1.444 (lava crust) within a single 35 m thick sheet lobe. Lava crust values are more radiogenic than any known mantle source, consistent with previous data indicating that neither an enriched reservoir nor the sub-continental lithospheric mantle are likely to have sourced these basalts. Rather, these data indicate that lavas emplaced during the earliest stages of eruption have higher degrees of crustal contamination. These results highlight the limitations of applying chemostratigraphic correlation across continental flood basalt provinces, the use of single data points to define melt sources and magmatic processes, and the dangers of using conventional isochron techniques in such basalt sequences for absolute chronology.

  15. Axial focusing of impact energy in the earth`s interior: A possible link to flood basalts and hotspots

    Energy Technology Data Exchange (ETDEWEB)

    Boslough, M.B.; Chael, E.P.; Trucano, T.G.; Crawford, D.A.; Campbell, D.L.

    1994-12-01

    We present the results of shock physics and seismological computational simulations that show how energy from a large impact can be coupled to the interior of the Earth. The radially-diverging shock wave generated by the impact decays to linearly elastic seismic waves. These waves reconverge (minus attenuation) along the axis of symmetry between the impact and its antipode. The locations that experience the most strain cycles with the largest amplitudes will dissipate the most energy and have the largest increases in temperature (for a given attenuation efficiency). We have shown that the locus of maximum energy deposition in the mantle lies along the impact axis. Moreover, the most intense focusing is within the asthenosphere at the antipode, within the range of depths where mechanical energy is most readily converted to heat. We propose that if large impacts on the Earth leave geological evidence anywhere other than the impact site itself, it will be at the antipode. We suggest that the most likely result of the focusing for a sufficiently large impact, consistent with features observed in the geological record, would be a flood basalt eruption at the antipode followed by hotspot volcanism. A direct prediction of this model would be the existence of undiscovered impact structures whose reconstructed locations would be antipodal to flood basalt provinces. One such structure would be in the Indian Ocean, associated with the Columbia River Basalts and Yellowstone; another would be a second K/T impact structure in the Pacific Ocean, associated with the Deccan Traps and Reunion.

  16. Memories of Earth Formation in the Modern Mantle: W Isotopic Composition of Flood Basalt Lavas

    Science.gov (United States)

    Rizo Garza, H. L.; Walker, R. J.; Carlson, R.; Horan, M. F.; Mukhopadhyay, S.; Francis, D.; Jackson, M. G.

    2015-12-01

    Four and a half billion years of geologic activity has overprinted much of the direct evidence for processes involved in Earth's formation and its initial chemical differentiation. Xenon isotopic ratios [1] and 3He/22Ne ratios [2] suggest that heterogeneities formed during Earth's accretion have been preserved to the present time. New opportunities to learn about early Earth history have opened up with the development of analytical techniques that allow high precision analysis of short-lived isotopic systems. The Hf-W system (t½ = 8.9 Ma) is particularly valuable for studying events that occurred during the first ~50 Ma of Solar System history. Here we report new data for ~ 60 Ma Baffin Bay and ~ 120 Ma Ontong Java Plateau lava samples. Both are large igneous provinces that may have sampled a primitive, less degassed deep mantle reservoir that has remained isolated since shortly after Earth formation [3,4]. Three samples analyzed have 182W/184W ratios that are 10 to 48 ppm higher than our terrestrial standard. These excesses in 182W are the highest ever measured in terrestrial rocks, and may reflect 182W ingrowth in an early-formed high Hf/W mantle domain that was produced by magma ocean differentiation [5]. Long and short-lived Sm-Nd systematics in these samples, however, are inconsistent with this hypothesis. The 182W excessses could rather reflect the derivation of these lavas from a mantle reservoir that was isolated from late accretionary additions [6]. The chondritic initial Os isotopic compositions and highly siderophile element abundances of these samples, however, are inconsistent with this interpretation. Tungsten concentrations for the Baffin Bay and Ontong Java Plateau samples range from 23 ppb to 62 ppb, and are negatively correlated with their 182W/184W ratios. We propose that the source reservoirs for these flood basalts likely formed through Hf/W fractionation caused by core-forming events occuring over a protacted time interval during Earth

  17. The new petrographic data about the Maymecha-Kotuy area of the Siberian flood-basalt province

    Science.gov (United States)

    Latyshev, Anton; Veselovskiy, Roman

    2010-05-01

    The Maymecha-Kotuy area of the Siberian flood-basalt province is of great interest because of its exceptional composition of igneous rocks. Alkaline-ultramafic rocks prevail there over basalts. It seems to be the only such trap province in the world. Investigation of the magma evolution and revealing of sources of magma is the task of an immense importance. Now there is a discussion about possible connections between the mass extinction on the boundary between Paleozoic and Mesozoic and magmatic activity expressed in formation of the largest Siberian flood-basalt province. Absence of the precise correlation of Maymecha-Kotuy area with other areas of the Siberian province does not allow estimating duration and volumes of the eruption of traps. Another question is if eruption of traps was uninterrupted or it had several pulses of magmatic activity. The solution of this problem will let estimate the degree of possible influence of the flood-basalt eruption to the environment. The represented results of investigations comprise all five igneous suites of Maymecha-Kotuy area. Petrographic investigation included research of thin sections and microprobe analyzes. The most entire sequences of Arydzhangsky and Kogotoksky suites and partly sequences of Pravoboyarsky, Delkansky and Maymechinsky suites were studied. This research allowed to reveal that the section of "Truba" on the Kotuy River belongs to Onkuchaksky suite (former lower Kogotoksky subsuite) and to reconsider the petrography of Arydzhangsky suite. Also, the research of geochemistry based on data of Fedorenko et al. (1997, 2000) lets suggest the sources of magma and its evolution. According to the new paleomagnetic data (Pavlov, Veselovskiy, Fetisova, EGU-2010), the new scheme of correlation of Maymecha-Kotuy trap section with Norilsk trap section was worked out and it became possible to estimate character of the magmatic activity in this region. In addition, it makes the contribution into the working out the

  18. Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt.

    Science.gov (United States)

    Wang, Lei; Tian, Wei; Shi, Yongmin

    2017-08-07

    The morphology and structure of plumbing systems can provide key information on the eruption rate and style of basalt lava fields. The most powerful way to study subsurface geo-bodies is to use industrial 3D reflection seismological imaging. However, strategies to image subsurface volcanoes are very different from that of oil and gas reservoirs. In this study, we process seismic data cubes from the Northern Tarim Basin, China, to illustrate how to visualize sills through opacity rendering techniques and how to image the conduits by time-slicing. In the first case, we isolated probes by the seismic horizons marking the contacts between sills and encasing strata, applying opacity rendering techniques to extract sills from the seismic cube. The resulting detailed sill morphology shows that the flow direction is from the dome center to the rim. In the second seismic cube, we use time-slices to image the conduits, which corresponds to marked discontinuities within the encasing rocks. A set of time-slices obtained at different depths show that the Tarim flood basalts erupted from central volcanoes, fed by separate pipe-like conduits.

  19. Evidence for intense hydrothermal alteration associated with flood basalt volcanism during the birth of the Azores Plateau

    Science.gov (United States)

    Bach, W.; Busch, A.; Genske, F. S.; Beier, C.; Krumm, S.

    2017-12-01

    initial stages of flood basalt activity. The extreme hydrothermal alteration may hence be directly linked to the prolonged magmatic period during which excess melting produced a 13-km thick igneous crust. Our results indicate that marine plateau-forming events may cause transient highs in hydrothermal flux rates.

  20. Eocene to Miocene back-arc basin basalts and associated island arc tholeiites from northern Sulawesi (Indonesia): Implications for the geodynamic evolution of the Celebes basin

    International Nuclear Information System (INIS)

    Rangin, C.; Maury, R.C.; Bellon, H.; Cotten, J.; Polve, M.; Priadi, B.; Soeria-Atmadja, R.; Joron, J.L.

    1997-01-01

    Eocene BABB basalts intruded by tholeiitic and calk-alkalic island arc magmatic rocks are reported from the north arm of Sulawesi (Indonesia). Age and geochemical similarities between these basalts and those drilled in the Celebes Sea indicate this North Sulawesi volcanic arc was built on the same oceanic crust. The 25 deg late Neogene clockwise rotation of the north arm of Sulawesi following its collision with fragments of Australia (Sula, Buton) is not sufficient to explain the asymmetrical magnetic anomalies in the Celebes basin. The North Sulawesi island arc could be interpreted as having progressively retreated northward on its own Celebes sea back arc basin, during an episode of Palaeogene-early Neogene tectonic erosion along the trench. (authors)

  1. Stratigraphy and structural development of the southwest Isla Tiburón marine basin: Implications for latest Miocene tectonic opening and flooding of the northern Gulf of California

    Science.gov (United States)

    Bennett, Scott E. K.; Oskin, Michael; Dorsey, Rebecca; Iriondo, Alexander; Kunk, Michael J.

    2015-01-01

    foraminifera from this section. Results from biostratigraphy and geochronology thus constrain earliest marine deposition on SWIT to ca. 6.2 ± 0.2 Ma, coincident with a regional-scale latest Miocene marine incursion into the northern proto-Gulf of California. This regional marine incursion flooded the northernmost, >500-km-long portion of the Gulf of California shear zone, a narrow belt of localized strike-slip faulting, clockwise block rotation, and subsiding pull-apart basins. Oblique Pacific-North America relative plate motion gradually localized in the >1000-km-long Gulf of California shear zone ca. 9-6 Ma, subsequently permitting the punctuated south to north flooding of the incipient Gulf of California seaway.

  2. Mineralogy and geochemistry of picro-dolerite dykes from the central Deccan Traps flood basaltic province, India, and their geodynamic significance

    Science.gov (United States)

    Dongre, Ashish; Viljoen, K. S.; Rathod, A.

    2018-04-01

    Constituent mineral compositions and whole rock major element geochemistry of picro-dolerite dykes from the central part of the Deccan flood basalt province are presented and discussed. The dykes are characterized by an MgO content of about 13 wt%, coupled with 13-16 modal percents of olivine. A high whole rock molar Mg# value of 71 and the presence of magnesian olivine phenocrysts ( Fo78) are consistent with a primitive (i.e. unevolved) geochemistry. The nature and composition of clinopyroxene (augite and pigeonite), plagioclase feldspar (labradorite) and Fe-Ti oxides (mostly ilmenite and magnetite) are also discussed, with implications drawn with respect to the geodynamics. High MgO magmas and rocks such as picrites are generally considered to be indicative of plume magmatism, formed by high degrees of partial melting in, e.g. the high-temperature region of a plume head. Recent age data is consistent with a model in which the Deccan LIP picritic magmatism is associated with the main phase of Deccan Trap activity at 66 Ma, as a result of a syn- to post rifting phase associated with the impact of the Rèunion mantle plume. It is speculated that the differentiation of primary olivine basaltic magma of picritic composition, may have been the mechanism for the generation of alkalic basalts which occurs in the Deccan Trap basaltic sequence.

  3. ´Áā lava flows in the Deccan Volcanic Province, India, and their significance for the nature of continental flood basalt eruptions

    Science.gov (United States)

    Brown, Richard J.; Blake, S.; Bondre, N. R.; Phadnis, V. M.; Self, S.

    2011-08-01

    Newly identified ´áā lava flows outcrop intermittently over an area of ~110 km2 in the western Deccan Volcanic Province (DVP), India. They occur in the upper Thakurvadi Formation in the region south of Sangamner. The flows, one of which is compound, are 15-25 m thick, and exhibit well-developed basal and flow-top breccias. The lavas have microcrystalline groundmasses and are porphyritic or glomerocrystic and contain phenocrysts of olivine, clinopyroxene or plagioclase feldspar. They are chemically similar to compound pāhoehoe flows at a similar stratigraphic horizon along the Western Ghats. Petrographic and geochemical differences between ´áā flows at widely spaced outcrops at the same stratigraphic horizon suggest that they are the product of several eruptions, potentially from different sources. Their presence in the DVP could suggest relative proximity to vents. This discovery is significant because ´áā lavas are generally scarce in large continental flood basalt provinces, which typically consist of numerous inflated compound pāhoehoe lobes and sheet lobes. Their scarcity is intriguing, and may relate to either their occurrence only in poorly preserved or exposed proximal areas or to the flat plateau-like topography of flood basalt provinces that may inhibit channelization and ´áā formation, or both. In this context, the ´áā flow fields described here are inferred to be the products of eruptions that produced unusually high-effusion-rate lavas compared to typical flood basalt eruptions. Whether these phases were transitional to lower intensity, sustained eruptions that fed extensive low effusion rate pāhoehoe flow fields remains unclear.

  4. Understanding heat and groundwater flow through continental flood basalt provinces: insights gained from alternative models of permeability/depth relationships for the Columbia Plateau, USA

    Science.gov (United States)

    Burns, Erick R.; Williams, Colin F.; Ingebritsen, Steven E.; Voss, Clifford I.; Spane, Frank A.; DeAngelo, Jacob

    2015-01-01

    Heat-flow mapping of the western USA has identified an apparent low-heat-flow anomaly coincident with the Columbia Plateau Regional Aquifer System, a thick sequence of basalt aquifers within the Columbia River Basalt Group (CRBG). A heat and mass transport model (SUTRA) was used to evaluate the potential impact of groundwater flow on heat flow along two different regional groundwater flow paths. Limited in situ permeability (k) data from the CRBG are compatible with a steep permeability decrease (approximately 3.5 orders of magnitude) at 600–900 m depth and approximately 40°C. Numerical simulations incorporating this permeability decrease demonstrate that regional groundwater flow can explain lower-than-expected heat flow in these highly anisotropic (kx/kz ~ 104) continental flood basalts. Simulation results indicate that the abrupt reduction in permeability at approximately 600 m depth results in an equivalently abrupt transition from a shallow region where heat flow is affected by groundwater flow to a deeper region of conduction-dominated heat flow. Most existing heat-flow measurements within the CRBG are from shallower than 600 m depth or near regional groundwater discharge zones, so that heat-flow maps generated using these data are likely influenced by groundwater flow. Substantial k decreases at similar temperatures have also been observed in the volcanic rocks of the adjacent Cascade Range volcanic arc and at Kilauea Volcano, Hawaii, where they result from low-temperature hydrothermal alteration.

  5. Ultrasonic P- and S-Wave Attenuation and Petrophysical Properties of Deccan Flood Basalts, India, as Revealed by Borehole Studies

    Science.gov (United States)

    Vedanti, Nimisha; Malkoti, Ajay; Pandey, O. P.; Shrivastava, J. P.

    2018-03-01

    Petrophysical properties and ultrasonic P- and S-wave attenuation measurements on 35 Deccan basalt core specimens, recovered from Killari borehole site in western India, provide unique reference data-sets for a lesser studied Deccan Volcanic Province. These samples represent 338-m-thick basaltic column, consisting four lava flows each of Ambenali and Poladpur Formations, belonging to Wai Subgroup of the Deccan volcanic sequence. These basalt samples are found to be iron-rich (average FeOT: 13.4 wt%), but relatively poor in silica content (average SiO2: 47.8 wt%). The saturated massive basalt cores are characterized by a mean density of 2.91 g/cm3 (range 2.80-3.01 g/cm3) and mean P- and S-wave velocities of 5.89 km/s (range 5.01-6.50 km/s) and 3.43 km/s (range 2.84-3.69 km/s), respectively. In comparison, saturated vesicular basalt cores show a wide range in density (2.40-2.79 g/cm3) as well as P-wave (3.28-4.78 km/s) and S-wave (1.70-2.95 km/s) velocities. Based on the present study, the Deccan volcanic sequence can be assigned a weighted mean density of 2.74 g/cm3 and a low V p and V s of 5.00 and 3.00 km/s, respectively. Such low velocities in Deccan basalts can be attributed mainly to the presence of fine-grained glassy material, high iron contents, and hydrothermally altered secondary mineral products, besides higher porosity in vesicular samples. The measured Q values in saturated massive basalt cores vary enormously (Q p: 33-1960 and Q s: 35-506), while saturated vesicular basalt samples exhibit somewhat lesser variation in Q p (6-46) as well as Q s (5-49). In general, high-porosity rocks exhibit high attenuation, but we observed the high value of attenuation in some of the massive basalt core samples also. In such cases, energy loss is mainly due to the presence of fine-grained glassy material as well as secondary alteration products like chlorophaeite, that could contribute to intrinsic attenuation. Dominance of weekly bound secondary minerals might also be

  6. Paleomagnetic Secular Variation Constraints on the Rapid Eruption of the Emeishan Continental Flood Basalts in Southwestern China and Northern Vietnam

    Science.gov (United States)

    Xu, Yingchao; Yang, Zhenyu; Tong, Ya-Bo; Jing, Xianqing

    2018-04-01

    Estimating the duration of magma eruptions using isotopic dating methods is difficult because of the intrinsic errors of the technique regarding the dated materials (such as zircon). However, the long-term variation of the geomagnetic field recorded by lava flows can be used to estimate the net duration of an eruption sequence. The Emeishan basalts at Dongchuan, with a thickness of 630 m, yielded a reliable characteristic remanent magnetization of normal polarity and which passed the fold test (Tauxe & Watson, 1994, https://doi.org/10.1016/0012-821X(94)90006-X). Stratigraphic and magnetostratigraphic correlations of the Emeishan basalts in the Dongchuan section with other sections indicate that the eruption of the Emeishan basalts at Dongchuan spans the entire normal polarity zone in the early stage of the Emeishan large igneous province. A flow-by-flow analysis of geomagnetic directions of the Emeishan basalts at Dongchuan indicates that four directional groups and fifteen individual lava directions were recorded, with a net duration (excluding quiescent intervals) of no more than 3100 years. The averaged site directions from the Emeishan basalts with normal polarity conforming to a geocentric axial dipole direction indicate that this interval is longer than 104-105 years. In addition, a magnetostratigraphic study indicates that the normal polarity interval recorded by the Emeishan basalts was shorter than 2-20 × 104 years. Thus, the total duration of the normal polarity stage of the Emeishan large igneous province was roughly 105 years. There is a possible relationship between the rapid eruption and the Late Capitanian mass extinction (259.8 ± 0.4 Ma, Henderson et al., 2012).

  7. Eocene to Miocene back-arc basin basalts and associated island arc tholeiites from northern Sulawesi (Indonesia): Implications for the geodynamic evolution of the Celebes basin; Basaltes de bassin arriere-arc de l`Eocene-Miocene et tholeiites d`arc insulaire associees du nord Sulawesi (Indonesie): implications pour l`evolution geodynamique du bassin des Celebes

    Energy Technology Data Exchange (ETDEWEB)

    Rangin, C. [Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France); Maury, R.C.; Bellon, H.; Cotten, J. [Universite de Bretagne Occidentale, 29 - Brest (France); Polve, M. [Universite Paul Sabatier, 31 - Toulouse (France); Priadi, B.; Soeria-Atmadja, R. [Department of Geology, ITB, Bandung (Indonesia); Joron, J.L. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche sur l`Etat Condense, les Atomes et les Molecules

    1997-12-31

    Eocene BABB basalts intruded by tholeiitic and calk-alkalic island arc magmatic rocks are reported from the north arm of Sulawesi (Indonesia). Age and geochemical similarities between these basalts and those drilled in the Celebes Sea indicate this North Sulawesi volcanic arc was built on the same oceanic crust. The 25 deg late Neogene clockwise rotation of the north arm of Sulawesi following its collision with fragments of Australia (Sula, Buton) is not sufficient to explain the asymmetrical magnetic anomalies in the Celebes basin. The North Sulawesi island arc could be interpreted as having progressively retreated northward on its own Celebes sea back arc basin, during an episode of Palaeogene-early Neogene tectonic erosion along the trench. (authors) 37 refs.

  8. On the potential for CO2 mineral storage in continental flood basalts – PHREEQC batch- and 1D diffusion–reaction simulations

    Directory of Open Access Journals (Sweden)

    Van Pham Thi

    2012-06-01

    Full Text Available Abstract Continental flood basalts (CFB are considered as potential CO2 storage sites because of their high reactivity and abundant divalent metal ions that can potentially trap carbon for geological timescales. Moreover, laterally extensive CFB are found in many place in the world within reasonable distances from major CO2 point emission sources. Based on the mineral and glass composition of the Columbia River Basalt (CRB we estimated the potential of CFB to store CO2 in secondary carbonates. We simulated the system using kinetic dependent dissolution of primary basalt-minerals (pyroxene, feldspar and glass and the local equilibrium assumption for secondary phases (weathering products. The simulations were divided into closed-system batch simulations at a constant CO2 pressure of 100 bar with sensitivity studies of temperature and reactive surface area, an evaluation of the reactivity of H2O in scCO2, and finally 1D reactive diffusion simulations giving reactivity at CO2 pressures varying from 0 to 100 bar. Although the uncertainty in reactive surface area and corresponding reaction rates are large, we have estimated the potential for CO2 mineral storage and identified factors that control the maximum extent of carbonation. The simulations showed that formation of carbonates from basalt at 40 C may be limited to the formation of siderite and possibly FeMg carbonates. Calcium was largely consumed by zeolite and oxide instead of forming carbonates. At higher temperatures (60 – 100 C, magnesite is suggested to form together with siderite and ankerite. The maximum potential of CO2 stored as solid carbonates, if CO2 is supplied to the reactions unlimited, is shown to depend on the availability of pore space as the hydration and carbonation reactions increase the solid volume and clog the pore space. For systems such as in the scCO2 phase with limited amount of water, the total carbonation potential is limited by the amount of water present

  9. Compound-specific carbon isotopes from Earth’s largest flood basalt eruptions directly linked to the end-Triassic mass extinction

    Science.gov (United States)

    Whiteside, Jessica H.; Olsen, Paul E.; Eglinton, Timothy; Brookfield, Michael E.; Sambrotto, Raymond N.

    2010-01-01

    A leading hypothesis explaining Phanerozoic mass extinctions and associated carbon isotopic anomalies is the emission of greenhouse, other gases, and aerosols caused by eruptions of continental flood basalt provinces. However, the necessary serial relationship between these eruptions, isotopic excursions, and extinctions has never been tested in geological sections preserving all three records. The end-Triassic extinction (ETE) at 201.4 Ma is among the largest of these extinctions and is tied to a large negative carbon isotope excursion, reflecting perturbations of the carbon cycle including a transient increase in CO2. The cause of the ETE has been inferred to be the eruption of the giant Central Atlantic magmatic province (CAMP). Here, we show that carbon isotopes of leaf wax derived lipids (n-alkanes), wood, and total organic carbon from two orbitally paced lacustrine sections interbedded with the CAMP in eastern North America show similar excursions to those seen in the mostly marine St. Audrie’s Bay section in England. Based on these results, the ETE began synchronously in marine and terrestrial environments slightly before the oldest basalts in eastern North America but simultaneous with the eruption of the oldest flows in Morocco, a CO2 super greenhouse, and marine biocalcification crisis. Because the temporal relationship between CAMP eruptions, mass extinction, and the carbon isotopic excursions are shown in the same place, this is the strongest case for a volcanic cause of a mass extinction to date. PMID:20308590

  10. InSAR observations of aseismic slip associated with an earthquake swarm in the Columbia River flood basalts

    Science.gov (United States)

    Wicks, Charles; Thelen, W.; Weaver, C.; Gomberg, J.; Rohay, A.; Bodin, P.

    2011-01-01

    In 2009 a swarm of small shallow earthquakes occurred within the basalt flows of the Columbia River Basalt Group (CRBG). The swarm occurred within a dense seismic network in the U.S. Department of Energys Hanford Site. Data from the seismic network along with interferometric synthetic aperture radar (InSAR) data from the European Space Agencys (ESA) ENVISAT satellite provide insight into the nature of the swarm. By modeling the InSAR deformation data we constructed a model that consists of a shallow thrust fault and a near horizontal fault. We suggest that the near horizontal lying fault is a bedding-plane fault located between basalt flows. The geodetic moment of the modeled fault system is about eight times the cumulative seismic moment of the swarm. Precise location estimates of the swarm earthquakes indicate that the area of highest slip on the thrust fault, ???70mm of slip less than ???0.5km depth, was not located within the swarm cluster. Most of the slip on the faults appears to have progressed aseismically and we suggest that interbed sediments play a central role in the slip process. Copyright 2011 by the American Geophysical Union.

  11. Geology of the saucer-shaped sill near Mahad, western Deccan Traps, India, and its significance to the Flood Basalt Model

    Science.gov (United States)

    Duraiswami, Raymond A.; Shaikh, Tahira N.

    2013-07-01

    An ˜22-m-thick saucer-shaped sill occurs near Mahad and is exposed as a curvilinear, miniature ridge within the Deccan Traps. The sill has variable dips (42-55°). It has a 7.1-km long axis and 5.3 km short axis (aspect ratio of 1.4) and is larger than the MV sill of the Golden Valley sill complex, South Africa and the Panton sill, Australia. The sill has distinct glassy upper and lower chilled margins with a coarse-grained highly jointed core. The samples from the margin are invariably fractured and iron stained because of deuteric alteration. The rock from the sill is plagioclase-phyric basalt. At least three thick sill-like apophyses emanate from the base of the main sill. The apophyses change direction because of bending and thinning from a horizontal concordant sheet at the top to a discordant inclined form that bends again to pass into a lower horizontal concordant sheet. We interpret such features as `nascent saucer-shaped sills' that did not inflate to form nested sills. Geochemically, the sill consists of poorly differentiated tholeiitic basalt that has a restricted geochemical range. Critical trace element ratios and primitive mantle normalised trace and REE patterns indicate that the sills have geochemical affinities to the Poladpur chemical type and that the pahoehoe flow they intrude belongs to the Bushe Formation. Calculated magmatic overpressures during sill emplacement range from 8.4 to 11.3 MPa (for Young's modulus E = 5 GPa) and 16.7 to 22.5 MPa (for E=10 GPa) and depth to magma chamber ranges from 8.5 to 11.5 km ( E = 5 GPa) and 17.1 to 22.9 km ( E = 10 GPa), consistent with petrological and gravity modelling. The volume of the Mahad sill is approximately 276 km3 and is constant irrespective of the variations in the values of host-rock Young's modulus. In 1980, Cox (J Petrol 21:629-650, 1980) proposed a conceptual model of the crust-mantle section beneath the Karoo CFB which is considered as the fundamental model for flood basalt volcanism. Our

  12. Floods

    Science.gov (United States)

    Floods are common in the United States. Weather such as heavy rain, thunderstorms, hurricanes, or tsunamis can ... is breached, or when a dam breaks. Flash floods, which can develop quickly, often have a dangerous ...

  13. Reduction in Surface Ocean Carbon Storage across the Middle Miocene

    Science.gov (United States)

    Babila, T. L.; Sosdian, S. M.; Foster, G. L.; Lear, C. H.

    2017-12-01

    During the Middle Miocene, Earth underwent a profound climate shift from the warmth of the Miocene Climatic Optimum (MCO; 14-17 Ma) to the stable icehouse of today during the Middle Miocene Climate transition (MMCT). Elevated atmospheric carbon dioxide concentrations (pCO2) revealed by boron isotope records (δ11B) link massive volcanic outputs of Columbia River Flood Basalts to the general warmth of MCO. Superimposed on the long-term cooling trend (MMCT) is a gradual pCO2 decline and numerous positive carbon isotope (δ13C) excursions that indicate dynamic variations in the global carbon cycle. Enhanced organic carbon burial via marine productivity, increased silicate weathering and volcanic emission cessation are each invoked to explain the drawdown of pCO2. To better constrain the oceanic role in carbon sequestration over the Middle Miocene detailed records of carbonate chemistry are needed. We present high resolution Boron/Calcium (B/Ca) and δ13C records in planktonic foraminifer T.trilobus spanning 12-17 Ma at ODP 761 (tropical eastern Indian Ocean) to document changes in surface ocean carbonate chemistry. An overall 30% increase in B/Ca ratios is expressed as two stepwise phases occurring at 14.7 and 13 Ma. Cyclic B/Ca variations are coherent with complimentary δ13C records suggesting a tight coupling between ocean carbonate chemistry parameters. Lower resolution B/Ca data at DSDP 588 (Pacific) and ODP 926 (Atlantic) corroborate the trends observed at ODP 761. We employ a paired approach that combines B/Ca (this study) to δ11B (Foster et al., 2012) and an ad hoc calibration to estimate changes in surface ocean dissolved inorganic carbon (DIC). We estimate a substantial decrease in surface ocean DIC spanning the Middle Miocene that culminates with modern day like values. This gradual decline in surface ocean DIC is coeval with existing deep-ocean records which together suggests a whole ocean reduction in carbon storage. We speculate that enhanced weathering

  14. The architecture of tholeiitic lava flows in the Neogene flood basalt piles of eastern Iceland: constraints on the mode of emplacemement

    Science.gov (United States)

    Oskarsson, B. V.; Riishuus, M. S.

    2012-12-01

    Tholeiites comprise 50-70% of the Neogene lava piles of eastern Iceland and have been described largely as flood basalts erupted from fissures (Walker, 1958). This study incorporates lava piles found in the Greater Reydarfjördur area and emprises the large-scale architecture of selected flows and flow groups, their internal structure and textures with the intention of assessing their mode of emplacement. A range of lava morphologies have been described and include: simple (tabular) flows with a'a and rubbly flow tops, simple flows with pahoehoe crust and compound pahoehoe flows, with simple flows being most common. Special attention is given here to the still poorly understood simple flows, which are characterized by extensive sheet lobes with individual sheet lengths frequently exceeding 2 km and reaching thicknesses of ~40 m (common aspect ratios The sheets in individual flow fields are emplaced side by side with an overlapping contact and are free of tubes. Their internal structure generally constitutes an upper vesicular crust with no or minor occurrences of horizontal vesicle zones, a poorly vesicular core and a thin basal vesicular zone. The normalized core/crust thickness ratios resemble modern compound pahoehoe flows in many instances (0.4-0.7), but with the thicker flows reaching ratios of 0.9. Flow crusts are either pahoehoe, rubbly or scoriaceous with torn and partially welded scoria and clinker. Frequently, any given flow morphology is repeated in sequences of three to four flows with direct contacts. Preliminary assessments suggest that simple flows are the product of high and sustained effusion rates from seemingly short-lived fissures. Simple flows with a'a flow tops may comprise the annealed emplacement mode of sheet flows and channeled a'a, in which the flow propagated as a single unit, whereas the brecciated flow top formed by continuous tearing and brecciation as occurs in channeled lava flowing at high velocity. The absence of a clinkery basal

  15. Sr-Nd-Pb isotopic constraints on the nature of the mantle sources involved in the genesis of the high-Ti tholeiites from northern Paraná Continental Flood Basalts (Brazil)

    Science.gov (United States)

    Rocha-Júnior, Eduardo R. V.; Marques, Leila S.; Babinski, Marly; Nardy, Antônio J. R.; Figueiredo, Ana M. G.; Machado, Fábio B.

    2013-10-01

    There has been little research on geochemistry and isotopic compositions in tholeiites of the Northern region from the Paraná Continental Flood Basalts (PCFB), one of the largest continental provinces of the world. In order to examine the mantle sources involved in the high-Ti (Pitanga and Paranapanema) basalt genesis, we studied Sr, Nd, and Pb isotopic systematics, and major, minor and incompatible trace element abundances. The REE patterns of the investigated samples (Pitanga and Paranapanema magma type) are similar (parallel to) to those of Island Arc Basalts' REE patterns. The high-Ti basalts investigated in this study have initial (133 Ma) 87Sr/86Sr ratios of 0.70538-0.70642, 143Nd/144Nd of 0.51233-0.51218, 206Pb/204Pb of 17.74-18.25, 207Pb/204Pb of 15.51-15.57, and 208Pb/204Pb of 38.18-38.45. These isotopic compositions do not display any correlation with Nb/Th, Nb/La or P2O5/K2O ratios, which also reflect that these rocks were not significantly affected by low-pressure crustal contamination. The incompatible trace element ratios and Sr-Nd-Pb isotopic compositions of the PCFB tholeiites are different to those found in Tristan da Cunha ocean island rocks, showing that this plume did not play a substantial role in the PCFB genesis. This interpretation is corroborated by previously published osmium isotopic data (initial γOs values range from +1.0 to +2.0 for high-Ti basalts), which also preclude basalt generation by melting of ancient subcontinental lithospheric mantle. The geochemical composition of the northern PCFB may be explained through the involvement of fluids and/or small volume melts related to metasomatic processes. In this context, we propose that the source of these magmas is a mixture of sublithospheric peridotite veined and/or interlayered with mafic components (e.g., pyroxenites or eclogites). The sublithospheric mantle (dominating the osmium isotopic compositions) was very probably enriched by fluids and/or magmas related to the

  16. Moessbauer Studies of Volhynian Basalts

    International Nuclear Information System (INIS)

    Bakun-Czubarow, N.; Milczarski, J.; Galazka-Friedman, J.; Szlachta, K.; Forder, S.

    2011-01-01

    The Volhynian basalts studied belong to the effusive-tuffogenic Volhynian Series (Slawatycze Series in Poland), being the large Ediacaran continental igneous province, that covers an area of 200 000 km 2 in the western margin of East European Craton. The series is underlain by the Cryogenian terrigenous Polesie Series with doleritic sills and dikes. The Volhynian Series consists of the rock beds belonging to the three volcanic cycles with different ratios of flood basalts to pyroclastics. The aim of the study was recognition of primary and secondary Fe-bearing minerals, particularly Fe- and Fe-Ti oxides as well as determination of iron oxidation state, that is an important tool in the search for native copper deposits in these rocks. For Moessbauer studies the following rock samples were chosen: the Polesie Series dolerites, the Volhynian Series basalts from the Ukrainian quarries and drill-holes, e.g. from the Volodymir Volhynskaya drilling hole; the Slawatycze Series basalts from Kaplonosy drill-hole in Poland. In the Kaplonosy basalts the content of magnetite decreases with depth, which may be caused by magma differentiation due to fractional crystallization, when Mg content decreases as Ti and Fe - increases in basic magma. In the Kaplonosy basalts the Fe 2+ /Fe 3+ ratio increases with depth, which points to the increase of iron oxidation with the progress of basaltic magma differentiation. (authors)

  17. {sup 40}K-{sup 40}Ar dating of the Late Miocene transition from calc-alkaline to alkali basalt series, Northwestern Algeria; Datation {sup 40}K-{sup 40}Ar de la transition du volcanisme calco-alcalin au volcanisme alcalin en Oranie au Miocene superieur

    Energy Technology Data Exchange (ETDEWEB)

    Louni-Hacini, A; Megartsi, M; Semroud, B [Algiers Univ. (Algeria). Faculte des Sciences; Bellon, H; Maury, R C; Cotten, J; Coutelle, A [Brest Univ., 29 (France); Coulon, C [Aix-Marseille-3 Univ., 13 - Marseille (France)

    1995-12-01

    Neogene volcanic rocks from the northwestern coast of Algeria include calc-alkaline to shoshonitic andesites and dacites (Sahel of Oran and M`Sirda areas) and alkali basalts (Tafna valley). Seventeen new {sup 40}K-{sup 40}Ar ages indicate that these volcanics were emplaced during two distinct periods, from 11.7 to 7.2 Ma and ca. 4 Ma, respectively. All the andesites and dacites were emplaced during the first period, and their trace element characteristics are typical of subduction -and/or collision- related magmas. They are enriched in large-ion lithophile elements and display negative Nb anomalies. The associated alkali basalts are chemically heterogeneous, and contain variable amounts of TiO{sub 2} and P{sub 2}O{sub 5}. Their multielement plots show either positive or slightly negative Nb anomalies. These features suggest that the Neogene volcanics studied derive from two different types of mantle sources, i.e. an enriched sub-continental mantle and an upper mantle carrying a subduction-related geochemical imprint. The latter component may have inherited its specific signature from an earlier subduction event. This ``orogenic`` imprint tends to disappear through time as the contribution of the sub-continental mantle increases. (authors). 12 refs., 4 figs., 2 tabs.

  18. Scientific results from the deepened Lopra-1 borehole, Faroe Islands: Wire-line log-based stratigraphy of flood basalts from the Lopra-1/1A well, Faroe Islands

    Directory of Open Access Journals (Sweden)

    Boldreel, Lars O.

    2006-07-01

    Full Text Available The present study shows that it is possible to use conventional borehole logs to perform a detailed lithological/stratigraphical division of a column of subaerially extruded basalt. A stratigraphical division of the subaerial flood basalts penetrated by the Lopra-1/1A well has been carried out using new wire-line logging data measured in 1996 in the interval 200–2489 m depth. Resistivity data acquired in the interval 200–2178 m depth during 1981 after the initial drilling of the Lopra-1 well have also been incorporated. Eighty-six individual flow units, 18 compound flows and two dolerite dykes have been identified by combining the NPHI porosity, RHOB density, P-, S- and Stonely-sonic transit time, calliper and resistivity logs. Fifty-two sedimentary/tuffaceous layers have also been identified using the CGR and SGR gamma ray and potassium logs in combination with the aforementioned logs. Within the flow units, sonic velocity, density and resistivity are highest in the core where porosity is lowest. This relation is reversed in the uppermost and basal zones of the flow units. The sonic velocity in the core seems to be independent of the thickness of the flow unit. Porous zones seem abundant in some cores and the total section of cores containing porous zones constitutes more than 70% of the thickness of its flow unit, but where porous zones are absent the core makes up only roughly 50% of the thickness of the flow. It is suggested that the flow units with porous cores represent aa flows (88% of the flow units and the others pahoehoe flows (12% of the flow units.The log pattern of the flow units (crust, core and basal zone is similar to log patterns reported from other basalt plateaux. However the patterns in Lopra-1/1A show a larger variation than elsewhere,suggesting that the flow units are more complex vertically than previously thought. Statistical analysis of P-, S- and Stonely-waves, RHOB, NPHI, resistivity, gamma and calliper logs has

  19. Paraná flood basalt volcanism primarily limited to 1 Myr beginning at 135 Ma: New 40Ar/39Ar ages for rocks from Rio Grande do Sul, and critical evaluation of published radiometric data

    Science.gov (United States)

    Baksi, Ajoy K.

    2018-04-01

    40Ar/39Ar step heating analyses were carried out on seven rocks (five basalts, an andesite and a rhyolite) from the southern Paraná Province ( 28°S-30°S); they yield plateau/isochron ages of 135-134 Ma, in good agreement with published step heating data on rocks from the same area. Critical review of laser spot isochron ages for rocks from the Province, ranging from 140 to 130 Ma, are shown to be unreliable estimates of crystallization ages, as the rocks were substantially altered; step heating results on three of these rocks thought to yield good plateau ages, are shown to be incorrect, as a result of a technicality in dating procedures followed. U-Pb ages on zircon and baddeleyite separated from a variety of rock types ( 30°S-23°S) fall in the range 135 to 134 Ma. All reliable 40Ar/39Ar and U-Pb ages indicate volcanism was sharply focused, initiated at 135 Ma, and 1 Myr in duration; no variation of age with either latitude or longitude is noted, Scrutiny of published 40Ar/39Ar ages on the Florianopolis dykes shows they cannot be used as reliable crystallization ages. U-Pb work shows that this dyke swarm was formed coevally with the main part of the Parana province. Most of the published 40Ar/39Ar ages on the Ponta Grossa dyke swarm are unreliable; a few ages appear reliable and suggest the magmatic event in this area, may have postdated the main Paraná pulse by 1-2 Myr. A single 40Ar/39Ar age from a high-Nb basalt in the southernmost part ( 34°S) of the Paraná at 135 Ma, highlights the need for further radiometric work on other areas of this flood basalt province. The Paraná Province postdates the time of the Jurassic-Cretaceous bound­ary by 10 Myr.

  20. Repository site definition in basalt: Pasco Basin, Washington

    International Nuclear Information System (INIS)

    Guzowski, R.V.; Nimick, F.B.; Muller, A.B.

    1982-03-01

    Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi 2 (5180 km 2 ) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood basalts with interbedded and overlying sedimentary units. This sequence rests upon a basement of probably diverse rock types that may range in age from precambrian through early Tertiary. Although a large amount of information is available on the hydrology of the unconfined aquifer system, ground-water flow within the basin is, in general, poorly understood. Recharge areas for the Mabton interbed and the Saddle Mountains Formation are the highlands surrounding the basin with the flow for these units toward Gable Butte - Gable Mountain and Lake Wallula. Gable Butte - Gable Mountain probably is a ground-water sink, although the vertical flow direction in this zone is uncertain. The amount of upward vertical leakage from the Saddle Mountains Formation into the overlying sediments or to the Columbia River is unknown. Units underlying the Mabton interbed may have a flow scheme similar to those higher units or a flow scheme dominated by interbasin flow. Upward vertical leakage either throughout the basin, dominantly to the Columbia River, or dominantly to Lake Wallula has been proposed for the discharge of the lower units. None of these proposals is verified. The lateral and vertical distribution of major and minor ions in solution, Eh and pH, and ion exchange between basalt and ground-water are not well defined for the basin. Changes in the redox potential from the level of the subsurface facility to the higher stratigraphic levels along with the numerous other factors influencing K/sub d/, result in a poor understanding of the retardation process

  1. Repository site definition in basalt: Pasco Basin, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Guzowski, R.V.; Nimick, F.B.; Muller, A.B.

    1982-03-01

    Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi/sup 2/ (5180 km/sup 2/) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood basalts with interbedded and overlying sedimentary units. This sequence rests upon a basement of probably diverse rock types that may range in age from precambrian through early Tertiary. Although a large amount of information is available on the hydrology of the unconfined aquifer system, ground-water flow within the basin is, in general, poorly understood. Recharge areas for the Mabton interbed and the Saddle Mountains Formation are the highlands surrounding the basin with the flow for these units toward Gable Butte - Gable Mountain and Lake Wallula. Gable Butte - Gable Mountain probably is a ground-water sink, although the vertical flow direction in this zone is uncertain. The amount of upward vertical leakage from the Saddle Mountains Formation into the overlying sediments or to the Columbia River is unknown. Units underlying the Mabton interbed may have a flow scheme similar to those higher units or a flow scheme dominated by interbasin flow. Upward vertical leakage either throughout the basin, dominantly to the Columbia River, or dominantly to Lake Wallula has been proposed for the discharge of the lower units. None of these proposals is verified. The lateral and vertical distribution of major and minor ions in solution, Eh and pH, and ion exchange between basalt and ground-water are not well defined for the basin. Changes in the redox potential from the level of the subsurface facility to the higher stratigraphic levels along with the numerous other factors influencing K/sub d/, result in a poor understanding of the retardation process.

  2. A field investigation of the basaltic ring structures of the Channeled Scabland and the relevance to Mars

    Science.gov (United States)

    Kestay, Laszlo P.; Jaeger, Windy L.

    2015-01-01

    The basaltic ring structure (BRS) is a class of peculiar features only reported in the Channeled Scabland of eastern Washington State. They have been suggested to be good analogs, however, for some circular features on Mars. BRSs are found where Pleistocene floods scoured the Columbia River Basin, stripping off the uppermost part of the Miocene Columbia River Basalt Group and exposing structures that were previously embedded in the lava. The “Odessa Craters,” near Odessa, WA, are 50–500-m-wide BRSs that are comprised of discontinuous, concentric outcrops of subvertically-jointed basalt and autointrusive dikes. Detailed field investigation of the Odessa Craters in planform and a cross-sectional exposure of a similar structure above Banks Lake, WA, lead us to propose that BRSs formed by concurrent phreatovolcanism and lava flow inflation. In this model, phreatovolcanic (a.k.a., “rootless”) cones formed on a relatively thin, active lava flow; the lava flow inflated around the cones, locally inverting topography; tensile stresses caused concentric fracturing of the lava crust; lava from within the molten interior of the flow exploited the fractures and buried the phreatovolcanic cones; and subsequent erosive floods excavated the structures. Another population of BRSs near Tokio Station, WA, consists of single-ringed, raised-rimmed structures that are smaller and more randomly distributed than the Odessa Craters. We find evidence for a phreatovolcanic component to the origin as well, and hypothesize that they are either flood-eroded phreatovolcanic cones or Odessa Crater-like BRSs. This work indicates that BRSs are not good analogs to the features on Mars because the martian features are found on the uneroded surfaces. Despite this, the now superseded concepts for BRS formation are useful for understanding the formation of the martian features.

  3. Floods and Flash Flooding

    Science.gov (United States)

    Floods and flash flooding Now is the time to determine your area’s flood risk. If you are not sure whether you ... If you are in a floodplain, consider buying flood insurance. Do not drive around barricades. If your ...

  4. Feasibility of storing radioactive wastes in Columbia River basalts

    International Nuclear Information System (INIS)

    Deju, R.A.

    1976-01-01

    In 1968 Atlantic Richfield Hanford Company initiated a study to assess the feasibility of final geologic storage of Hanford defense, radioactive waste in deep caverns constructed in the Columbia River flood basalts. The project, which included geologic studies, hydrologic tests, heat flow analysis, compatibility analysis, and tectonic studies, was suspended in 1972 before completion of interpretive work. In 1976 the interpretation and documentation were completed. These data may be valuable in qualifying the Columbia River flood basalts as a viable medium for final geologic storage of commercial radioactive waste. The findings to date are summarized, and the proposed future work is presented

  5. Miocene Antarctic Terrestrial Realm

    Science.gov (United States)

    Ashworth, A. C.; Lewis, A.; Marchant, D. R.

    2009-12-01

    The discovery of several locations in the Transantarctic Mountains that contain macrofossils and pollen is transforming our understanding of late Cenozoic Antarctica. The most southerly location is on the Beardmore Glacier (85.1°S) about 500 km from the South Pole. The environment was an active glacial margin in which plants, insects and freshwater mollusks inhabited the sand and gravel bars and small lakes on an outwash plain. In addition to leaves and wood of dwarf Nothofagus (Southern Beech) shrubs, achenes of Ranunculus (Buttercup), in situ cushion growth forms of mosses and a vascular plant, the assemblages contains various exoskeletal parts of carabid and curculionid beetles and a cyclorrhaphan fly, the shells of freshwater bivalve and gastropod species and a fish tooth. Initially the deposits were assigned a Pliocene age (3.5 Ma) but a mid- to early Miocene age is more probable (c. 14 - 25 Ma) based on correlation of fossil pollen from the deposits with 39Ar/40Ar dated pollen assemblages from the McMurdo Dry Valleys locations. The oldest location within the Dry Valleys also involved an active ice margin but was part of a valley system that was completely deglaciated for intervals long enough for thick paleosols to develop. The Friis Hills fossil deposits of the Taylor Valley region (77.8°S) are at least 19.76 Ma based on the 39Ar/40Ar age of a volcanic ash bed. The valley floor during the non-glacial phases had poorly-drained soils and the extensive development of mossy mires. Wood and leaves of Nothofagus are abundant in lacustrine deposits. The silts of shallow fluvial channels contain abundant megaspores and spiky leaves of the aquatic lycopod Isoetes (Quillwort). Fossils of beetles are also present in these deposits. During the glacial phases, proglacial lakes were surrounded by dwarfed, deciduous Nothofagus shrubs. The youngest fossils recovered from the Dry Valleys are from the Olympus Range (77.5°S) with an age of 14.07 Ma. The environment was an

  6. Flooding and Flood Management

    Science.gov (United States)

    Brooks, K.N.; Fallon, J.D.; Lorenz, D.L.; Stark, J.R.; Menard, Jason; Easter, K.W.; Perry, Jim

    2011-01-01

    Floods result in great human disasters globally and nationally, causing an average of $4 billion of damages each year in the United States. Minnesota has its share of floods and flood damages, and the state has awarded nearly $278 million to local units of government for flood mitigation projects through its Flood Hazard Mitigation Grant Program. Since 1995, flood mitigation in the Red River Valley has exceeded $146 million. Considerable local and state funding has been provided to manage and mitigate problems of excess stormwater in urban areas, flooding of farmlands, and flood damages at road crossings. The cumulative costs involved with floods and flood mitigation in Minnesota are not known precisely, but it is safe to conclude that flood mitigation is a costly business. This chapter begins with a description of floods in Minneosta to provide examples and contrasts across the state. Background material is presented to provide a basic understanding of floods and flood processes, predication, and management and mitigation. Methods of analyzing and characterizing floods are presented because they affect how we respond to flooding and can influence relevant practices. The understanding and perceptions of floods and flooding commonly differ among those who work in flood forecasting, flood protection, or water resource mamnagement and citizens and businesses affected by floods. These differences can become magnified following a major flood, pointing to the need for better understanding of flooding as well as common language to describe flood risks and the uncertainty associated with determining such risks. Expectations of accurate and timely flood forecasts and our ability to control floods do not always match reality. Striving for clarity is important in formulating policies that can help avoid recurring flood damages and costs.

  7. Geochemistry of cenozoic basaltic rocks from Shandong province and its implication for mantle process in North China

    International Nuclear Information System (INIS)

    Lee Yungtan; Chen Juchin; Huang Shaowei; Shih Jyhyi; Lin Menglung; Juang Wenshing; Yang Huaijen

    2006-01-01

    Cenozoic (Miocene to Pleistocene) basaltic rocks found in Shandong province of northern China include tholeiite, olivine tholeiite and alkali basalt. We present major, trace and rare earth elements data of these basalts and together with Sr-Nd isotopic data in the literatures to discuss the petrogenesis of these basalts. The basalts from Penglai area have higher K, Na and P and incompatible elements, but lower Ca, Mg and compatible elements contents than those from Changle area of Shandong province. Spidergrams indicate that Cenozoic basalts from Shandong province have geochemical characteristics similar to those of ocean island basalts (OIB) with slight positive Nb anomaly. The negative Ba, Rb and K anomalies found in the alkali basalts suggest the presence of residual phlogopite in the mantle source, indicating a metasomatic event occurred before the partial melting. The 143 Nd/ 144 Nd vs. 87 Sr/ 86 Sr plot suggested that basalts from Shandong province can be produced by MORB and EM-I components mixing. We propose that the EM-I type lithospheric mantle may have been produced by the recent H 2 O-CO 2 -fluids metasomatism and the fluids may be derived from dehydration of the subducted slab. Based on Shaw's equation, the basalts from eastern and central Shandong province have undergone different degrees of particle melting from the mantle source. Degrees of partial melting and chemical composition of basalts from Shandong province suggest that the lithosphere has thickened progressively since the Miocene. On the basis of Ar-Ar ages of this study and the fractional crystallization model proposed by Brooks and Nielsen (1982), we suggest that basalts from Changle and Penglai areas belong to different magmatic systems which have undergone fractional crystallization and evolved progressively to produce other types of basalts. (author)

  8. Basalt stratigraphy - Pasco Basin

    International Nuclear Information System (INIS)

    Waters, A.C.; Myers, C.W.; Brown, D.J.; Ledgerwood, R.K.

    1979-10-01

    The geologic history of the Pasco Basin is sketched. Study of the stratigraphy of the area involved a number of techniques including major-element chemistry, paleomagnetic investigations, borehole logging, and other geophysical survey methods. Grande Ronde basalt accumulation in the Pasco Basin is described. An illustrative log response is shown. 1 figure

  9. Carbon Sequestration in Olivine and Basalt Powder Packed Beds.

    Science.gov (United States)

    Xiong, Wei; Wells, Rachel K; Giammar, Daniel E

    2017-02-21

    Fractures and pores in basalt could provide substantial pore volume and surface area of reactive minerals for carbonate mineral formation in geologic carbon sequestration. In many fractures solute transport will be limited to diffusion, and opposing chemical gradients that form as a result of concentration differences can lead to spatial distribution of silicate mineral dissolution and carbonate mineral precipitation. Glass tubes packed with grains of olivine or basalt with different grain sizes and compositions were used to explore the identity and spatial distribution of carbonate minerals that form in dead-end one-dimensional diffusion-limited zones that are connected to a larger reservoir of water in equilibrium with 100 bar CO 2 at 100 °C. Magnesite formed in experiments with olivine, and Mg- and Ca-bearing siderite formed in experiments with flood basalt. The spatial distribution of carbonates varied between powder packed beds with different powder sizes. Packed beds of basalt powder with large specific surface areas sequestered more carbon per unit basalt mass than powder with low surface area. The spatial location and extent of carbonate mineral formation can influence the overall ability of fractured basalt to sequester carbon.

  10. Petrochemistry and origin of basalt breccia from Ban Sap Sawat area, Wichian Buri, Phetchabun, central Thailand

    Directory of Open Access Journals (Sweden)

    Phisit Limtrakun

    2013-08-01

    Full Text Available Thailand is usually considered to be controlled by escape tectonics associated with India-Asia collision during theLate Cenozoic, and basaltic volcanism took place in this extensional period. This volcanism generated both subaqueous andsubaerial lava flows with tholeiitic to alkalic basaltic magma. The subaqueous eruptions represented by the studied WichianBuri basalts, Ban Sap Sawat in particular, are constituted by two main types of volcanic lithofacies, including lava flows andbasalt breccias. The lava flows are commonly porphyritic with olivine and plagioclase phenocrysts and microphenocrysts,and are uncommonly seriate textured. The basalt breccias are strongly vitrophyric texture with olivine and plagioclasephenocrysts and microphenocrysts. Chemical analyses indicate that both lava flows and basalt breccias have similar geochemical compositions, signifying that they were solidified from the same magma. Their chondrite normalized REE patternsand N-MORB normalized patterns are closely analogous to the Early to Middle Miocene tholeiites from central Sinkhote-Alinand Sakhalin, northeastern margin of the Eurasian continent which were erupted in a continental rift environment. The originfor the Wichian Buri basalts show similarity of lava flows and basalt breccias, in terms of petrography and chemical compositions, signifying that they have been formed from the same continental within-plate, transitional tholeiitic magma.

  11. Petrologic evolution of Miocene-Pliocene mafic volcanism in the Kangal and Gürün basins (Sivas-Malatya), central east Anatolia: Evidence for Miocene anorogenic magmas contaminated by continental crust

    Science.gov (United States)

    Kocaarslan, Ayça; Ersoy, E. Yalçın

    2018-06-01

    This study discusses the geochemical features of the Early-Middle Miocene and Pliocene basaltic (SiO2 = 46-52; MgO = 6-10 wt%) to andesitic (SiO2 = 59; MgO = 4 wt%) rocks exposed in the Gürün and Kangal basins (Sivas, eastern part of central Anatolia), respectively. The basaltic rocks are characterized by alkaline to tholeiitic affinities, while the more evolved andesitic samples show calc-alkaline affinity. Trace element variations reveal that they can be evaluated in three sub-groups, each represented by different contents of trace elements for given Nb contents. Primary magmas of each groups were likely produced by different degrees of partial melting ( 1-2, 2-3, 7-10% respectively) from a common mantle source, subsequently underwent different degrees of fractionation and crustal contamination. Derivation from a common mantle source of the primitive magmas of each group is supported by similar Sr, Nd and Pb isotopic ratios. Increasing degrees of partial melting seem to be responsible for the alkaline to tholeiitic variation among the basaltic samples, while higher degrees of crustal contamination (AFC) resulted in calc-alkaline affinity of the more evolved samples. Most primitive Pliocene samples show intra-plate (anorogenic) geochemical features, while the more evolved Miocene calc-alkaline samples resemble geochemically subduction-related (orogenic) magmatic rocks. However, on the basis of detailed geochemical models, we propose that the calc-alkaline affinity among the Miocene samples can also be gained by crustal contamination of their primary magmas which were also anorogenic in character. If this is true, overall, the Miocene and Pliocene basaltic to andesitic rocks in the Gürün and Kangal basins appear to may have formed by variable degrees of partial melting of a common anorogenic mantle that had not been subject to subduction-related metasomatism. This is an alternative approach to the general view assuming the Early-Middle Miocene magmatic activity

  12. K-Ar Geochronology and isotopic composition of the late oligocene- early miocene Ancud volcanic complex, Chiloe

    International Nuclear Information System (INIS)

    Munoz B, Jorge; Duhart O, Paul; Farmer, G. Lang; Stern, Charles R

    2001-01-01

    The Ancud Volcanic Complex (Gally and Sanchez , 1960) forms a portion of the Mid-Tertiary Coastal Magmatic Belt which outcrops in the area of northern Chiloe island. Main exposures occur at Ancud, Punta Polocue, Punihuil, Pumillahue, Tetas de Teguaco and Bahia Cocotue. The Ancud Volcanic Complex consists of basaltic to basaltic andesites lava flows and volcanic necks and rhyolitic pyroclastic flows and vitric domes. Previous studies indicate a Late Oligocene-Early Miocene age (Garcia et al., 1988; Stern and Vergara, 1992; Munoz et al., 2000). The Ancud Volcanic Complex covers and intrudes Palaeozoic-Triassic metamorphic rocks and is partially covered by an early to middle Miocene marine sedimentary sequence known as Lacui Formation (Valenzuela, 1982) and by Pleistocene glacial deposits (Heusser, 1990). At Punihuil locality, lava flows are interbedded with the lower part of the marine sedimentary sequence, which includes significant amounts of redeposited pyroclastic components. Locally, the presence of hyaloclastic breccias suggests interaction of magma with marine water (au)

  13. Complex layering of the Orange Mountain Basalt: New Jersey, USA

    Science.gov (United States)

    Puffer, John H.; Block, Karin A.; Steiner, Jeffrey C.; Laskowich, Chris

    2018-06-01

    The Orange Mountain Basalt of New Jersey is a Mesozoic formation consisting of three units: a single lower inflated sheet lobe about 70 m thick (OMB1), a middle pillow basalt about 10 to 20 m thick (OMB2), and an upper compound pahoehoe flow about 20 to 40 m thick (OMB3). The Orange Mountain Basalt is part of the Central Atlantic Magmatic Province. Quarry and road-cut exposures of OMB1 near Paterson, New Jersey, display some unusual layering that is the focus of this study. OMB1 exposures displays the typical upper crust, core, and basal crust layers of sheet lobes but throughout the Patterson area also display distinct light gray layers of microvesicular basalt mineralized with albite directly over the basal crust and under the upper crust. The lower microvesicular layer is associated with mega-vesicular diapirs. We propose that the upper and lower microvesicular layers were composed of viscous crust that was suddenly quenched before it could devolatilize immediately before the solidification of the core. During initial cooling, the bottom of the basal layer was mineralized with high concentrations of calcite and albite during a high-temperature hydrothermal event. Subsequent albitization, as well as zeolite, prehnite, and calcite precipitation events, occurred during burial and circulation of basin brine heated by recurring Palisades magmatism below the Orange Mountain Basalt. Some of the events experienced by the Orange Mountain Basalt are unusual and place constraints on the fluid dynamics of thick flood basalt flows in general. The late penetration of vesicular diapirs through the entire thickness of the flow interior constrains its viscosity and solidification history.

  14. Oligocene stratigraphy across the Eocene and Miocene boundaries in the Valley of Lakes (Mongolia).

    Science.gov (United States)

    Daxner-Höck, Gudrun; Badamgarav, Demchig; Barsbold, Rinchen; Bayarmaa, Baatarjav; Erbajeva, Margarita; Göhlich, Ursula Bettina; Harzhauser, Mathias; Höck, Eva; Höck, Volker; Ichinnorov, Niiden; Khand, Yondon; López-Guerrero, Paloma; Maridet, Olivier; Neubauer, Thomas; Oliver, Adriana; Piller, Werner; Tsogtbaatar, Khishigjav; Ziegler, Reinhard

    2017-01-01

    Cenozoic sediments of the Taatsiin Gol and TaatsiinTsagaan Nuur area are rich in fossils that provide unique evidence of mammal evolution in Mongolia. The strata are intercalated with basalt flows. 40 Ar/ 39 Ar data of the basalts frame the time of sediment deposition and mammal evolution and enable a composite age chronology for the studied area. We investigated 20 geological sections and 6 fossil localities of Oligocene and early Miocene deposits from this region. Seventy fossil beds yielded more than 19,000 mammal fossils. This huge collection encompasses 175 mammal species: 50% Rodentia, 13% Eulipotyphla and Didelphomorphia, and 12% Lagomorpha. The remaining 25% of species are distributed among herbivorous and carnivorous large mammals. The representation of lower vertebrates and gastropods is comparatively poor. Several hundred SEM images illustrate the diversity of Marsupialia, Eulipotyphla, and Rodentia dentition and give insight into small mammal evolution in Mongolia during the Oligocene and early Miocene. This dataset, the radiometric ages of basalt I (∼31.5 Ma) and basalt II (∼27 Ma), and the magnetostratigraphic data provide ages of mammal assemblages and time ranges of the Mongolian biozones: letter zone A ranges from ∼33 to ∼31.5 Ma, letter zone B from ∼31.5 to ∼28 Ma, letter zone C from ∼28 to 25.6 Ma, letter zone C1 from 25.6 to 24 Ma, letter zone C1-D from 24 to ∼23 Ma, and letter zone D from ∼23 to ∼21 Ma.

  15. Preliminary Hydrogeologic Characterization Results from the Wallula Basalt Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    B.P. McGrail; E. C. Sullivan; F. A. Spane; D. H. Bacon; G. Hund; P. D. Thorne; C. J. Thompson; S. P. Reidel; F. S. Colwell

    2009-12-01

    The DOE's Big Sky Regional Carbon Sequestration Partnership has completed drilling the first continental flood basalt sequestration pilot borehole to a total depth (TD) of 4,110 feet on the Boise White Paper Mill property at Wallula, Washington. Site suitability was assessed prior to drilling by the 2007-2008 acquisition, processing and analysis of a four-mile, five-line three component seismic swath, which was processed as a single data-dense line. Analysis of the seismic survey data indicated a composite basalt formation thickness of {approx}8,000 feet and absence of major geologic structures (i.e., faults) along the line imaged by the seismic swath. Drilling of Wallula pilot borehole was initiated on January 13, 2009 and reached TD on April 6, 2009. Based on characterization results obtained during drilling, three basalt breccia zones were identified between the depth interval of 2,716 and 2,910 feet, as being suitable injection reservoir for a subsequent CO2 injection pilot study. The targeted injection reservoir lies stratigraphically below the massive Umtanum Member of the Grande Ronde Basalt, whose flow-interior section possesses regionally recognized low-permeability characteristics. The identified composite injection zone reservoir provides a unique and attractive opportunity to scientifically study the reservoir behavior of three inter-connected reservoir intervals below primary and secondary caprock confining zones. Drill cuttings, wireline geophysical logs, and 31one-inch diameter rotary sidewall cores provided geologic data for characterization of rock properties. XRF analyses of selected rock samples provided geochemical characterizations of the rocks and stratigraphic control for the basalt flows encountered by the Wallula pilot borehole. Based on the geochemical results, the pilot borehole was terminated in the Wapshilla Ridge 1 flow of the Grande Ronde Basalt Formation. Detailed hydrologic test characterizations of 12 basalt interflow

  16. Geology, geochemistry and 40K-40Ar geochronometry of Miocene magmatism in Algiers area, Northern Algeria

    International Nuclear Information System (INIS)

    Belanteur, O.; Ouabadi, A.; Semroud, B.; Megartsi, M.H.; Fourcade, S.

    1995-01-01

    Miocene magmatic rocks outcrop within a narrow coastal strip east of Algiers. They include basaltic and andesitic lava flows and intrusions (Dellys, Cap Djinet), the Thenia granodioritic plug and the dacitic to rhyolitic lavas and pyroclastic flows from Zemmouri El Bahri and El Kerma. Despite the effects of hydrothermal alteration, 40 K- 40 Ar ages coupled with micropalaeontological data lead to recognition of two emplacement events at 16-15 and 14-12 Ma, respectively. All the studied calc-alkaline to potassic calc-alkaline rocks are enriched in highly incompatible elements and display negative Nb anomalies. Acid magmas have a pronounced crustal imprint ( 87 Sr 86 Sr i =3D 0.7082 to 0.7155; δ 18 O =3D +9 to +13 per mill) which together with La/Nb ratios argues for the occurrence of upper crustal contamination processes. However, the Nb-depletion of the associated basalts suggest that the studied magmas derive from a mantle source which underwent subduction-related metasomatic enrichments prior to their Miocene emplacement. (authors). 13 refs., 3 figs., 2 tabs

  17. Elastic Anisotropy of Basalt

    Science.gov (United States)

    Becker, K.; Shapiro, S.; Stanchits, S.; Dresen, G.; Kaselow, A.; Vinciguerra, S.

    2005-12-01

    Elastic properties of rocks are sensitive to changes of the in-situ stress and damage state. In particular, seismic velocities are strongly affected by stress-induced formation and deformation of cracks or shear-enhanced pore collapse. The effect of stress on seismic velocities as a result of pore space deformation in isotropic rock at isostatic compression may be expressed by the equation: A+K*P-B*exp (-D*P) (1), where P=Pc-Pp is the effective pressure, the pure difference between confining pressure and pore pressure. The parameter A, K, B and D describe material constants determined using experimental data. The physical meaning of the parameters is given by Shapiro (2003, in Geophysics Vol.68(Nr.2)). Parameter D is related to the stress sensitivity of the rock. A similar relation was derived by Shapiro and Kaselow (2005, in Geophysics in press) for weak anisotropic rocks under arbitrary load. They describe the stress dependent anisotropy in terms of Thomson's (1986, in Geophysics, Vol. 51(Nr.10)) anisotropy parameters ɛ and γ as a function of stress in the case of an initially isotropic rock: ɛ ∝ E2-E3, γ ∝ E3-E2 (2) with Ei=exp (D*Pi). The exponential terms Ei are controlled by the effective stress components Pi. To test this relation, we have conducted a series of triaxial compression tests on dry samples of initially isotropic Etnean Basalt in a servo-controlled MTS loading frame equipped with a pressure cell. Confining pressure was 60, 40 and 20 MPa. Samples were 5 cm in diameter and 10 cm in length. Elastic anisotropy was induced by axial compression of the samples through opening and growth of microcracks predominantly oriented parallel to the sample axis. Ultrasonic P- and S- wave velocities were monitored parallel and normal to the sample axis by an array of 20 piezoceramic transducers glued to the surface. Preamplified full waveform signals were stored in two 12 channel transient recorders. According to equation 2 the anisotropy parameters are

  18. Hypsodont Myomiminae (Gliridae, Rodentia) from the Miocene and the Oligocene-Miocene boundary interval of Spain

    NARCIS (Netherlands)

    Daams, R.

    1990-01-01

    Fifty-one localities from the Oligocene-Miocene boundary interval and the Miocene of Spain have yielded nearly 4000 teeth of hypsodont Gliridae (Armantomys and Praearmantomys). The phylogeny and palaeoecology are discussed. Two new species of Armantomys (A. parsani sp. nov. from Ramblar 1 and A.

  19. Economic and ecologic importance of the non - metalic deposits in basalt maars of Southern Slovakia

    Directory of Open Access Journals (Sweden)

    Vass Dionýz

    1998-03-01

    Full Text Available By investigation of the basalt maars infill in Luèenská kotlina Depression the diatomite and alginite deposits have been found. Both maars belong to Podreèany basalt formation, Pontian (Late Miocene in age. By technological investigation it was proved the diatomite can be used in the building trade as raw materil for light tiles convenient especially for the construction of the saddle roof with attic appatments. The alginite can be used in the agriculture and horticulture, as a fertiliser becouse of humus, nutritive end same trace elements, a desodorant in livestoc feedlots, a water and nutritive elements trap to distribute them for the growing plants. The alginite can be used as well as in pharmacy and in different industrial branches. Both deposits are of high significance for the ecology and the nature protection.

  20. Age relationships and tectonic implications of late Cenozoic basaltic volcanism in Northland, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Smith, I E.M. [Department of Geology, Auckland University, Auckland (New Zealand); Okada, T [Okayama University of Science, Hiruzen Research Institute, Okayama (Japan); Itaya, T [Okayama University of Science, Hiruzen Research Institute, Okayama (Japan); Black, P M [Department of Geology, Auckland University, Auckland (New Zealand)

    1993-07-01

    An episode of late Miocene-Recent essentially basaltic volcanism is the latest in a sequence of magmatic events recognised in the tectonically complex geological development of the Northland Peninsula. New K-Ar dates together with an extensive collection of new major and trace element chemical analyses prompt a reassessment of the significance of these late Cenozoic basalts. The main time/space groupings recognised are Tertiary volcanics in the Kaikohe-Bay of Islands, Puhipuhi, Ti Point, and Stony Batter areas and Quaternary basalts in the Kaikohe-Bay of Islands and Whangarei areas and at Tara. Basalts in the Kaikohe-Bay of Islands area are transitional to alkalic in character, while those in the south are transitional to tholeiitic, with the Ti Point and Stony Batter rocks being geochemically distinct. A consistent model for these observations is that the magmas originate from different levels of a layered mantle source in which the upper part carries a geochemical signature inherited from an earlier subduction event. (author). 27 refs., 7 figs., 1 tab.

  1. Age relationships and tectonic implications of late Cenozoic basaltic volcanism in Northland, New Zealand

    International Nuclear Information System (INIS)

    Smith, I.E.M.; Okada, T.; Itaya, T.; Black, P.M.

    1993-01-01

    An episode of late Miocene-Recent essentially basaltic volcanism is the latest in a sequence of magmatic events recognised in the tectonically complex geological development of the Northland Peninsula. New K-Ar dates together with an extensive collection of new major and trace element chemical analyses prompt a reassessment of the significance of these late Cenozoic basalts. The main time/space groupings recognised are Tertiary volcanics in the Kaikohe-Bay of Islands, Puhipuhi, Ti Point, and Stony Batter areas and Quaternary basalts in the Kaikohe-Bay of Islands and Whangarei areas and at Tara. Basalts in the Kaikohe-Bay of Islands area are transitional to alkalic in character, while those in the south are transitional to tholeiitic, with the Ti Point and Stony Batter rocks being geochemically distinct. A consistent model for these observations is that the magmas originate from different levels of a layered mantle source in which the upper part carries a geochemical signature inherited from an earlier subduction event. (author). 27 refs., 7 figs., 1 tab

  2. Asthenosphere versus lithosphere as possible sources for basaltic magmas erupted during formation of the Red Sea

    International Nuclear Information System (INIS)

    Altherr, R.; Henjes-Kunst, F.; Baumann, A.

    1990-01-01

    Representative basalts from the axial trough of the Red Sea and from volcanic fields of the Arabian Peninsula ranging in composition from N-type MORB to basanite and in age from Early Miocene to Recent show a limited variation in their isotopic compositions: 87 Sr/ 86 Sr = 0.70240-0.70361, 206 Pb/ 204 Pb = 18.040-19.634, 207 Pb/ 204 Pb = 15.496-15.666, 208 Pb/ 204 Pb = 37.808-39.710, 143 Nd/ 144 Nd = 0.513194-0.512670. There is a poorly constrained correlation between chemical composition and isotope ratios: with increasing alkalinity, Sr and Pb isotope ratios increase and the Nd isotope ratio tends to decrease. In Pb isotope variation diagrams most of the basalts plot significantly above the NHRLs, irrespective of tectonic setting, i.e. thickness of underlying crust and/or lithosphere. MORBs from the axial trough of the Red Sea have higher Pb isotope ratios for a given 87 Sr/ 86 Sr than MORBs from the Indian Ocean ridges, including the Carlsberg Ridge. It is therefore suggested that both spreading ridges tap different convective systems in the asthenosphere. The tectonic setting of the basalts is reflected in their Nd-Sr isotope characteristics. Basalts from areas where the continental lithosphere is drastically thinned or absent (i.e. Red Sea axial trough and coastal plain, Afar) plot along a reference line defined by N-type MORB and Tristan da Cunha. Basalts erupted in areas with Pan-African crust of normal thickness and moderately thinned lithospheric mantle (i.e. rift shoulder) are characterized by relative low 143 Nd/ 144 Nd ratios and plot below the reference line towards an EM I component which is also found in the subcontinental lithospheric mantle. These differences in the Nd-Sr isotopic compositions of the basalts are independent of bulk-rock chemistry and are therefore controlled by tectonic setting alone. (orig./WL)

  3. Preliminary feasibility study on storage of radioactive wastes in Columbia River basalts. Volume I

    International Nuclear Information System (INIS)

    1976-11-01

    Geologic, hydrologic, heat transfer and rock-waste compatibility studies conducted by the Atlantic Richfield Hanford Company to evaluate the feasibility of storing nuclear wastes in caverns mined out into the Columbia River basalts are discussed. The succession of Columbia River Plateau flood basalts was sampled at various outcrops and in core holes and the samples were analyzed to develop a stratigraphic correlation of the various basalt units and sedimentary interbeds. Hydrologic tests were made in one bore hole to assess the degree of isolation in the various deep aquifers separated by thick basalt accumulations. Earthquake and tectonic studies were conducted to assess the tectonic stability of the Columbia River Plateau. Studies were made to evaluate the extent of heat dissipation from stored radioactive wastes. Geochemical studies were aimed at evaluating the compatibility between the radioactive wastes and the basalt host rocks. Data obtained to-date have allowed development of a hydrostratigraphic framework for the Columbia River Plateau and a preliminary understanding of the deep aquifer systems. Finally, the compilation of this information has served as a basis for planning the studies necessary to define the effectiveness of the Columbia River basalts for permanently isolating nuclear wastes from the biosphere

  4. Miocene freshwater Mollusca from western Brazilian Amazonia

    NARCIS (Netherlands)

    Wesselingh, F.P.; Ranzi, A.; Räsänen, M.E.

    2006-01-01

    Thirteen species of fossil molluscs are reported from the Solimões Formation of western Brazilian Amazonia. Based on mammalian chronology of the Solimões Formation and radiometric ages reported from coeval deposits in adjacent Peru, the age of the fauna is established as Late Miocene. The fauna

  5. Late Miocene magnetostratigraphy in the Mediterranean

    NARCIS (Netherlands)

    Langereis, C.G.

    1984-01-01

    Reversals of the geomagnetic field In the geological past are recorded globally in the natural remanent magnetization (NRM) of igneous and sedimentary rock sequences. The accurate and rei iable reconstruction of this record is the basis of magnetostratigraphy. The magnetostratigraphy of Late Miocene

  6. Field-trip guide to the vents, dikes, stratigraphy, and structure of the Columbia River Basalt Group, eastern Oregon and southeastern Washington

    Science.gov (United States)

    Camp, Victor E; Reidel, Stephen P.; Ross, Martin E.; Brown, Richard J.; Self, Stephen

    2017-06-22

    The Columbia River Basalt Group covers an area of more than 210,000 km2 with an estimated volume of 210,000 km3. As the youngest continental flood-basalt province on Earth (16.7–5.5 Ma), it is well preserved, with a coherent and detailed stratigraphy exposed in the deep canyonlands of eastern Oregon and southeastern Washington. The Columbia River flood-basalt province is often cited as a model for the study of similar provinces worldwide.This field-trip guide explores the main source region of the Columbia River Basalt Group and is written for trip participants attending the 2017 International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly in Portland, Oregon, USA. The first part of the guide provides an overview of the geologic features common in the Columbia River flood-basalt province and the stratigraphic terminology used in the Columbia River Basalt Group. The accompanying road log examines the stratigraphic evolution, eruption history, and structure of the province through a field examination of the lavas, dikes, and pyroclastic rocks of the Columbia River Basalt Group.

  7. 40Ar-39Ar age determinations on the Owyhee basalt of the Columbia plateau

    International Nuclear Information System (INIS)

    Bottomley, R.J.; York, D.

    1976-01-01

    40 Ar/ 39 Ar step-heating analyses have been performed on 11 samples of basalt from sites near Owyhee Reservoir of southeastern Oregon, U.S.A. These rocks were extruded during the great flood basalt episode of the Pacific Northwest. The whole-rock points are highly correlated on a plot of 40 Ar/ 36 Ar versus 39 Ar/ 36 Ar, corresponding to a common age of the samples of 14.3+-0.3 m.y. Inspite of this, individual 'plateau' plots of the age versus fraction of 39 Ar released do not give good plateaux. These age spectra exhibit to varying degrees a common structure in which lower age values are found at higher temperatures. This pattern may result from a closed-system redistribution of the argon isotopes. The usefulness of grinding the basalts in removing a loosely held atmospheric argon component is confirmed. (Auth.)

  8. Miocene Soil Database: Global paleosol and climate maps of the Middle Miocene Thermal Maximum

    Science.gov (United States)

    Metzger, C. A.

    2013-12-01

    Paleosols, which record past climatic, biologic, and atmospheric conditions, can be used as a proxy to understand ancient terrestrial landscapes, paleoclimate, and paleoenvironment. In addition, the middle Miocene thermal maximum (~16 Ma) provides an ancient analog for understanding the effects of current and future climate change on soil and ecosystem regimes, as it contains records of shifts similar in magnitude to expected global climate change. The Miocene Soil Database (MSDB) combines new paleosol data from Australia and Argentina with existing and previously uncollated paleosol data from the literature and the Paleobiology Database. These data (n = 507) were then used to derive a paleogeographic map of climatically significant soil types zones during the Middle Miocene. The location of each diagnostic paleosol type (Aridisol, Alfisol, Mollisol, Histosol, Oxisol, and Ultisol) was plotted and compared with the extent of these soil types in the modern environment. The middle Miocene soil map highlights the extension of tropical soils (Oxisols, Ultisols), accompanied by thermophilic flora and fauna, into northern and southern mid-latitudes. Peats, lignites, and Histosols of wetlands were also more abundant at higher latitudes, especially in the northern hemisphere, during the middle Miocene. The paleosol changes reflect that the Middle Miocene was a peak of global soil productivity and carbon sequestration, with replacement of unproductive Aridisols and Gelisols with more productive Oxisols, Alfisols, Mollisols and Histosols. With expansion to include additional data such as soil texture, moisture, or vegetation type, the MSDB has the potential to provide an important dataset for computer models of Miocene climate shifts as well as future land use considerations of soils in times of global change.

  9. Geology, geochemistry and {sup 40}K-{sup 40}Ar geochronometry of Miocene magmatism in Algiers area, Northern Algeria; La magmatisme miocene de l`Est Algerois, geologie, geochimie et geochronologie {sup 40}K-{sup 40}Ar

    Energy Technology Data Exchange (ETDEWEB)

    Belanteur, O; Ouabadi, A; Semroud, B; Megartsi, M H [Algiers Univ. (Algeria). Faculte des Sciences; Bellon, H; Maury, R C; Coutelle, A [Brest Univ., 29 (France); Fourcade, S [Rennes-1 Univ., 35 (France)

    1996-12-31

    Miocene magmatic rocks outcrop within a narrow coastal strip east of Algiers. They include basaltic and andesitic lava flows and intrusions (Dellys, Cap Djinet), the Thenia granodioritic plug and the dacitic to rhyolitic lavas and pyroclastic flows from Zemmouri El Bahri and El Kerma. Despite the effects of hydrothermal alteration, {sup 40}K-{sup 40}Ar ages coupled with micropalaeontological data lead to recognition of two emplacement events at 16-15 and 14-12 Ma, respectively. All the studied calc-alkaline to potassic calc-alkaline rocks are enriched in highly incompatible elements and display negative Nb anomalies. Acid magmas have a pronounced crustal imprint ({sup 87}Sr{sup 86}Sr{sub i} =3D 0.7082 to 0.7155; {delta}{sup 18}O =3D +9 to +13 per mill) which together with La/Nb ratios argues for the occurrence of upper crustal contamination processes. However, the Nb-depletion of the associated basalts suggest that the studied magmas derive from a mantle source which underwent subduction-related metasomatic enrichments prior to their Miocene emplacement. (authors). 13 refs., 3 figs., 2 tabs.

  10. Subseafloor basalts as fungal habitats

    Science.gov (United States)

    Ivarsson, M.; Bengtson, S.

    2013-12-01

    The oceanic crust makes up the largest potential habitat for life on Earth, yet next to nothing is known about the abundance, diversity and ecology of its biosphere. Our understanding of the deep biosphere of subseafloor crust is, with a few exceptions, based on a fossil record. Surprisingly, a majority of the fossilized microorganisms have been interpreted or recently re-interpreted as remnants of fungi rather than prokaryotes. Even though this might be due to a bias in fossilization the presence of fungi in these settings can not be neglected. We have examined fossilized microorganisms in drilled basalt samples collected at the Emperor Seamounts in the Pacific Ocean. Synchrotron-radiation X-ray tomography microscopy (SRXTM) studies has revealed a complex morphology and internal structure that corresponds to characteristic fungal morphology. Chitin was detected in the fossilized hyphae, which is another strong argument in favour of a fungal interpretation. Chitin is absent in prokaryotes but a substantial constituent in fungal cell walls. The fungal colonies consist of both hyphae and yeast-like growth states as well as resting structures and possible fruit bodies, thus, the fungi exist in vital colonies in subseafloor basalts. The fungi have also been involved in extensive weathering of secondary mineralisations. In terrestrial environments fungi are known as an important geobiological agent that promotes mineral weathering and decomposition of organic matter, and they occur in vital symbiosis with other microorganisms. It is probable to assume that fungi would play a similar role in subseafloor basalts and have great impact on the ecology and on biogeochemical cycles in such environments.

  11. Large mammal burrows in late Miocene calcic paleosols from central Argentina: paleoenvironment, taphonomy and producers

    Directory of Open Access Journals (Sweden)

    María Cristina Cardonatto

    2018-05-01

    Full Text Available Large cylindrical sediment-filled structures interpreted as mammal burrows occur within the loess-paleosol sequence of the late Miocene Cerro Azul Formation of central Argentina. A total of 115 burrow fills from three localities were measured. They are typically shallowly dipping, subcylindrical, unbranched structures with rounded ends and lacking enlargements. The horizontal diameter of the burrows range between 0.15 and 1.50 m, with most of the burrows in the interval of 0.39 to 0.98 m. Geometric morphometric analysis of transverse cross-sections support their distinct subcircular and elliptical (horizontally flattened shapes. Burrow fills are typically laminated in the lower part and massive in the upper part. The laminated intervals reflect pulses of flowing water entering the abandoned burrow during moderate rains, whereas massive intervals reflect mass flow input of dense sediment-water mixtures during heavy rains that produced sheet floods. Approximately 1% of the burrows contained fragmentary, disarticulated and weathered mammal bones that were introduced in the open burrow by currents along with other sedimentary particles. Analysis of the tetrapod burrow fossil record suggests that Miocene burrows, including those studied herein, reflect a remarkable increase in the average size of the fossorial fauna. We conclude that large late Miocene mammals dug burrows essentially as a shelter against environmental extremes and to escape predation. The simple architecture of the burrows suggests that the producers essentially foraged aboveground. Several mammal groups acquired fossorial habits in response to cold and seasonally dry climatic conditions that prevailed during the late Miocene in southern South America. The considerable range of horizontal diameters of the studied burrows can be attributed to a variety of producers, including dasypodids, the notoungulate Paedotherium minor, Glyptodontidae and Proscelidodon sp.

  12. Regional stratigraphy, sedimentology, and tectonic significance of Oligocene-Miocene sedimentary and volcanic rocks, northern Baja California, Mexico

    Science.gov (United States)

    Dorsey, Rebecca J.; Burns, Beverly

    1994-01-01

    to viscous sediment gravity flows. Deposits of the Comondú Formation thin and fine systematically westward, from proximal volcanic conglomerate and breccia with thin basalt and andesite flows in the east, to distal volcaniclastic fluvial sandstone in the west. These proximal—distal relationships help to define the location and paleogeography of active arc-flanking volcaniclastic alluvial aprons of the Miocene magmatic arc in northern Baja California. A substantial late Miocene drop in regional base level (relative sea level) is best attributed to regional uplift caused by the renewal of magmatic and thermal activity in northern Baja California, which has continued to the present day.

  13. Geochemistry contribution of Pb isotopes on basalts origin study from Parana basin, Brazil

    International Nuclear Information System (INIS)

    Marques, L.S.; Dupre, B.; Allegre, C.J.

    1990-01-01

    This paper presents thirty new Pb-isotope and concentration data for low- and high-tiO sub(2) continental flood basalts of the Parana Basin. The results obtained from representative samples show significant differences with respect to type and location of these basic rocks. The low- and high-TiO sub(2) basalts from the northern region of the Parana Basin exhibit very similar Pb-isotope compositions. On the other hand, the low-TiO sub(2) basalts of central and southern areas, which exhibit low Sr initial isotope ratios (less than 0,7060), show very small variation in Pb isotope compositions which are highly enriched in radiogenic Pb in comparison with the analogues of northern region. The high-TiO sub(2) basic rocks analysed from northern and central regions have the same values for Pb isotope ratios, which are slightly more radiogenic compared with high-TiO sub(2) basalts from southern region. The data obtained, combined with other geochemical (major and trace elements, including rare earths) and isotope (Sr and Nd) results support the view that the basalts from northern and southern areas of the Parana Basin originated in lithospheric mantle reservoirs with different geochemical characteristics. (author)

  14. Basaltic cannibalism at Thrihnukagigur volcano, Iceland

    Science.gov (United States)

    Hudak, M. R.; Feineman, M. D.; La Femina, P. C.; Geirsson, H.

    2014-12-01

    Magmatic assimilation of felsic continental crust is a well-documented, relatively common phenomenon. The extent to which basaltic crust is assimilated by magmas, on the other hand, is not well known. Basaltic cannibalism, or the wholesale incorporation of basaltic crustal material into a basaltic magma, is thought to be uncommon because basalt requires more energy than higher silica rocks to melt. Basaltic materials that are unconsolidated, poorly crystalline, or palagonitized may be more easily ingested than fully crystallized massive basalt, thus allowing basaltic cannibalism to occur. Thrihnukagigur volcano, SW Iceland, offers a unique exposure of a buried cinder cone within its evacuated conduit, 100 m below the main vent. The unconsolidated tephra is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to a vent that produced lava and tephra during the ~4 Ka fissure eruption. Preliminary petrographic and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) analyses indicate that there are two populations of plagioclase present in the system - Population One is stubby (aspect ratio 2.1), subhedral to euhedral, and has much higher Ba/Sr ratios. Population One crystals are observed in the cinder cone, dike, and surface lavas, whereas Population Two crystals are observed only in the dike and surface lavas. This suggests that a magma crystallizing a single elongate population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the stubbier population of phenocrysts. This conceptual model for basaltic cannibalism is supported by field observations of large-scale erosion upward into the tephra, which is coated by magma flow-back indicating that magma was involved in the thermal etching. While the unique exposure at Thrihnukagigur makes it an exceptional place to investigate basaltic cannibalism, we suggest that it is not limited to this volcanic system. Rather it is a process that likely

  15. The Miocene carnivore assemblage of Greece

    Directory of Open Access Journals (Sweden)

    Koufos, G. D.

    2011-12-01

    Full Text Available The Miocene carnivore assemblage of Greece includes a great number of taxa, described in numerous articles since the first decades of the 19th Century. The present article is a revision of all these taxa, providing information about their history, localities, age, as well as their stratigraphic distribution and palaeoenvironment. The Early/Middle Miocene carnivore record of Greece is poor as the available fossiliferous sites and material are rare. However, the Late Miocene one is quite rich, including numerous taxa. The Miocene localities with carnivores and their age are given in a stratigraphic table covering the European Mammal zones from MN 4 to MN 13. The type locality, holotype, and some historical and morphological remarks are given for each taxon. Several carnivore taxa were erected from Greek material and new photos of their holotypes are given. The stratigraphic distribution of the Greek carnivore taxa indicates that they are covering the time span from ~19.0-5.3Ma. The majority of the Miocene taxa (Adcrocuta, Hyaenictitherium, Plioviverrops, Protictitherium, Ictitherium, Indarctos, Dinocrocuta, Promephitis disappeared at the end of Miocene. The composition of the Early/Middle Miocene carnivore assemblage of Greece includes mainly viverrids (Lophocyon, Euboictis, while the hyaenids, percrocutids, felids and mustelids are very few. On the contrary the Late Miocene assemblage is richer, including more subfamilies and species; the hyaenids and mustelids dominate, while the viverrids are absent. The Late Miocene carnivore guild structure is similar to that of the modern Serengeti, indicating a relatively open, savannah-like environment.

    La asociación de carnívoros miocenos de Grecia incluye un gran número de taxones, descritos en numerosos artículos desde las primeras décadas del siglo XIX. El presente artículo supone un esfuerzo de síntesis de todos estos taxones, suministrando información sobre su

  16. Subseafloor basalts as fungal habitats

    Directory of Open Access Journals (Sweden)

    M. Ivarsson

    2012-09-01

    Full Text Available The oceanic crust is believed to host the largest potential habitat for microbial life on Earth, yet, still we lack substantial information about the abundance, diversity, and consequence of its biosphere. The last two decades have involved major research accomplishments within this field and a change in view of the ocean crust and its potential to harbour life. Here fossilised fungal colonies in subseafloor basalts are reported from three different seamounts in the Pacific Ocean. The fungal colonies consist of various characteristic structures interpreted as fungal hyphae, fruit bodies and spores. The fungal hyphae are well preserved with morphological characteristics such as hyphal walls, septa, thallic conidiogenesis, and hyphal tips with hyphal vesicles within. The fruit bodies consist of large (∼50–200 µm in diameter body-like structures with a defined outer membrane and an interior filled with calcite. The fruit bodies have at some stage been emptied of their contents of spores and filled by carbonate-forming fluids. A few fruit bodies not filled by calcite and with spores still within support this interpretation. Spore-like structures (ranging from a few µm to ∼20 µm in diameter are also observed outside of the fruit bodies and in some cases concentrated to openings in the membrane of the fruit bodies. The hyphae, fruit bodies and spores are all closely associated with a crust lining the vein walls that probably represent a mineralized biofilm. The results support a fungal presence in deep subseafloor basalts and indicate that such habitats were vital between ∼81 and 48 Ma.

  17. Late Miocene (Proto-Gulf) Extension and Magmatism on the Sonoran Margin

    Science.gov (United States)

    Gans, P.; MacMillan, I.; Roldan-Quintana, J.

    2003-12-01

    Constraints on the magnitude and character of late Miocene (Proto-Gulf) deformation on the Sonoran margin of the Gulf of California extensional province are key to understanding how and when Baja California was captured by the Pacific plate and how strain was partitioned during the early stages of this transtensional rift system. Our new geologic mapping in southwestern Sonora and 40Ar/39Ar dating of pre-, syn-, and post-tectonic volcanic units indicate that late Miocene deformation and volcanic activity were largely restricted to a NW-trending, 100-120 km wide belt adjacent to the coast. Inboard of this belt, NW-SE extension is mainly older (>15 Ma) and occurred in an intra-arc or back-arc setting. Proto-Gulf deformation within the coastal belt was profoundly transtensional, with NW-striking, dextral strike slip faults operating in concert with N-S and NNE-striking normal and oblique slip faults to produce an inferred NW or NNW tectonic transport direction. The total amount of late Miocene NW directed dextral shear within the coastal belt is still poorly constrained, but may exceed 100 km. The locus of deformation and volcanic activity migrated westward or northwestward within the Sonoran coastal belt. in the eastern portion (Sierra Libre and Sierra El Bacatete) major volcanic activity commenced at ˜13.0 Ma and peaked at 12.0 Ma, and major faulting and tilting is bracketed between 12.0 and 10.6 Ma. Further west in the Sierra El Aguaje/San Carlos region, major volcanic activity commenced at 11.5 Ma and peaked at 10.5 Ma, and most faulting and tilting is bracketed between 10.7 and 9.3 Ma. On the coastal mountains northwest of San Carlos, rift related faulting and tilting continued after 8.5 Ma. Voluminous late Miocene (13-8 Ma) volcanic rocks within the Sonoran coastal belt were erupted from numerous centers (e.g. Sierra Libre, Guaymas, Sierra El Aguaje). These thick volcanic sections are compositionally diverse (basalt to rhyolite, with abundant dacite and

  18. The Late Miocene paleogeography of the Amazon Basin and the evolution of the Amazon River system

    Science.gov (United States)

    Latrubesse, Edgardo M.; Cozzuol, Mario; da Silva-Caminha, Silane A. F.; Rigsby, Catherine A.; Absy, Maria Lucia; Jaramillo, Carlos

    2010-05-01

    On the basis of paleontological content (vertebrates and palynology) and facies analysis from river banks, road cuts, and three wells, we have assigned the uppermost levels of the Solimões Formation in western Amazonia, Brazil, to the Late Miocene. The vertebrate fossil record from outcropping sediments is assigned to the Huayquerian-Mesopotamian mammalian biozones, spanning 9-6.5 Ma. Additionally, we present results that demonstrate that deposits in Peruvian Amazonia attributed to Miocene tidal environments are actually fluvial sediments that have been misinterpreted (both environmentally and chronologically) by several authors. The entire Late Miocene sequence was deposited in a continental environment within a subsiding basin. The facies analysis, fossil fauna content, and palynological record indicate that the environment of deposition was dominated by avulsive rivers associated with megafan systems, and avulsive rivers in flood basins (swamps, lakes, internal deltas, and splays). Soils developed on the flatter, drier areas, which were dominated by grasslands and gallery forest in a tropical to subtropical climate. These Late Miocene sediments were deposited from westward of the Purus arch up to the border of Brazil with Peru (Divisor Ranges) and Bolivia (Pando block). Eastward of the Iquitos structural high, however, more detailed studies, including vertebrate paleontology, need to be performed to calibrate with more precision the ages of the uppermost levels of the Solimões Formation. The evolution of the basin during the late Miocene is mainly related to the tectonic behavior of the Central Andes (˜ 3°-15°S). At approximately 5 Ma, a segment of low angle of subduction was well developed in the Nazca Plate, and the deformation in the Subandean foreland produced the inland reactivation of the Divisor/Contamana Ranges and tectonic arrangements in the Eastern Andes. During the Pliocene southwestern Brazilian Amazonia ceased to be an effective sedimentary

  19. Molluscan radiations and landscape evolution in Miocene Amazonia

    NARCIS (Netherlands)

    Wesselingh, F.P.

    2008-01-01

    This PhD study aims to exploit the rich archive provided by the Miocene mollusc fauna of the Pebas Formation and other inland Miocene Amazonian formations to reconstruct landscape evolution and biotic development in lowland Amazonia during the Neogene. Over 160 samples from more than 70 Pebas

  20. The Origin of Basalt and Cause of Melting Beneath East Antarctica as Revealed by the Southernmost Volcanoes on Earth

    Science.gov (United States)

    Reindel, J. L.; Panter, K. S.; Smellie, J. L.; McIntosh, W. C.

    2017-12-01

    Mt. Early and Sheridan Bluff are two basaltic monogenetic volcanoes located at 87° South latitude at the head of the Scott Glacier. These Early Miocene volcanoes lie 800 km from any other volcano and 200 km inland from the shoulder of the West Antarctic Rift System (WARS), which is the foci of most Cenozoic alkaline volcanism in Antarctica. Preliminary 40Ar/39Ar dates suggest that Mt. Early is older than previously determined and closer in age to Sheridan Bluff ( 19 Ma). Petrography, mineral chemistry and whole rock major and trace element concentrations are used to characterize the basalts and to determine whether they are genetically related to mafic volcanism in the WARS. The basalts are porphyritic with phenocrysts of olivine (Fo 58-84%), plagioclase (An 48-67%) ± clinopyroxene (Wo 43-48%). Whole rock MgO range from 10 to 4 wt.% and have restricted SiO2 (48 to 50 wt.%) contents. The basalts vary from alkaline (up to 6 wt.% Ne-normative) to subalkaline (up to 6 wt.% Hy-normative). The alkaline basalts that occur at both Mt. Early and Sheridan Bluff are more strongly enriched in incompatible elements (La 33-49 ppm, Ba 270-484 ppm, Sr 712-1009 ppm), have LaN/YbN ratios >10 and show prominent Pb negative anomalies with only slight K negative anomalies on primitive mantle normalized, multi-element diagrams. Subalkaline basalts (only at Sheridan Bluff) have lower concentrations of incompatible elements (La 14-16 ppm, Ba 110-144 ppm, and Sr 358-380 ppm), LaN/YbN ratios base of the East Antarctic craton and its replacement by warmer asthenosphere has been proposed for this region based on geophysical evidence (Heeszel et al., 2016). The volcanism may constrain the timing of this event. Heeszel et al. (2016) JGR, 121, 1758-1775.

  1. Mammal extinctions in the Vallesian (Upper Miocene)

    Science.gov (United States)

    Agusti, J.; Moya-Sola, S.

    The term Vallesian was created by Crusafont (1950) to designate the first European Mammalian palaeofaunas containing the equid Hipparion, the remainder of the faunas being composed of typical elements coming from the Middle Miocene such as Micromeryx, Euprox, Sansanosmilus, Pseudaelurus, and Listriodon. Thus, the Aragonian-Vallesian boundary does not show a strong change among European Miocene mammalian faunas (Agusti et al., 1984). On the other hand, the Lower Vallesian/Upper Vallesian transition corresponds to a major biotic crisis. This boudnary is characterized by the disappearence of most of the Aragonian artiodactyl forms such as Protragocerus, Miotragocerus, Listriodon, Hyotherium, Parachleusastochoerus, etc. Among the rodents, this crisis affects the family Eomyidae and most of the cricetid and glirid species. On the other hand, a number of eastern elements appear in the area at the same time. This is the case of the suid Schizochoerus and the murid Progonomys. Other eastern forms are Tragoportax, Graecoryx, Adcrocuta, Paramachairodus, Microstonyx, etc. Most of these are typical elements of the next Mammal stage, the Turolian. Thus, whereas the Lower Vallesian fauna has a typical Aragonian composition except for Hipparion. After the Middle Vallesian event, the Upper Vallesian faunas are already largely Turolian in character. The possible factors involved in this extinction event are discussed.

  2. Genetic interpretation of lead-isotopic data from the Columbia River basalt group, Oregon, Washington, and Idaho.

    Science.gov (United States)

    Church, S.E.

    1985-01-01

    Lead-isotopic data for the high-alumina olivine plateau basalts and most of the Colombia River basalt group plot within the Cascade Range mixing array. The data for several of the formations form small, tight clusters and the Nd and Sr isotopic data show discrete variation between these basalt groups. The observed isotopic and trace-element data from most of the Columbia River basalt group can be accounted for by a model which calls for partial melting of the convecting oceanic-type mantle and contamination by fluids derived from continental sediments which were subducted along the trench. These sediments were transported in the low-velocity zone at least 400 km behind the active arc into a back-arc environment represented by the Columbia Plateau province. With time, the zone of melting moved up, resulting in the formation of the Saddle Mt basalt by partial melting of a 2600 m.y.-old sub-continental lithosphere characterized by high Th/U, Th/Pb, Rb/Sr and Nd/Sm ratios and LREE enrichment. Partial melting of old sub-continental lithosphere beneath the continental crust may be an important process in the formation of continental tholeiite flood basalt sequences world-wide. -L.di H.

  3. Experimental research on continuous basalt fiber and basalt-fibers-reinforced polymers

    Science.gov (United States)

    Zhang, Xueyi; Zou, Guangping; Shen, Zhiqiang

    2008-11-01

    The interest for continuous basalt fibers and reinforced polymers has recently grown because of its low price and rich natural resource. Basalt fiber was one type of high performance inorganic fibers which were made from natural basalt by the method of melt extraction. This paper discusses basic mechanical properties of basalt fiber. The other work in this paper was to conduct tensile testing of continuous basalt fiber-reinforced polymer rod. Tensile strength and stress-strain curve were obtained in this testing. The strength of rod was fairly equal to rod of E-glass fibers and weaker than rod of carbon fibers. Surface of crack of rod was studied. An investigation of fracture mechanism between matrix and fiber was analyzed by SEM (Scanning electron microscopy) method. A poor adhesion between the matrix and fibers was also shown for composites analyzing SEM photos. The promising tensile properties of the presented basalt fibers composites have shown their great potential as alternative classical composites.

  4. Geochemical discrimination of five pleistocene Lava-Dam outburst-flood deposits, western Grand Canyon, Arizona

    Science.gov (United States)

    Fenton, C.R.; Poreda, R.J.; Nash, B.P.; Webb, R.H.; Cerling, T.E.

    2004-01-01

    Pleistocene basaltic lava dams and outburst-flood deposits in the western Grand Canyon, Arizona, have been correlated by means of cosmogenic 3He (3Hec) ages and concentrations of SiO2, Na2O, K2O, and rare earth elements. These data indicate that basalt clasts and vitroclasts in a given outburst-flood deposit came from a common source, a lava dam. With these data, it is possible to distinguish individual dam-flood events and improve our understanding of the interrelations of volcanism and river processes. At least five lava dams on the Colorado River failed catastrophically between 100 and 525 ka; subsequent outburst floods emplaced basalt-rich deposits preserved on benches as high as 200 m above the current river and up to 53 km downstream of dam sites. Chemical data also distinguishes individual lava flows that were collectively mapped in the past as large long-lasting dam complexes. These chemical data, in combination with age constraints, increase our ability to correlate lava dams and outburst-flood deposits and increase our understanding of the longevity of lava dams. Bases of correlated lava dams and flood deposits approximate the elevation of the ancestral river during each flood event. Water surface profiles are reconstructed and can be used in future hydraulic models to estimate the magnitude of these large-scale floods.

  5. Geologic structure of the eastern mare basins. [lunar basalts

    Science.gov (United States)

    Dehon, R. A.; Waskom, J. D.

    1976-01-01

    The thickness of mare basalts in the eastern maria are estimated and isopachs of the basalts are constructed. Sub-basalt basin floor topography is determined, and correlations of topographic variations of the surface with variations in basalt thickness or basin floor topography are investigated.

  6. The Origin of Noble Gas Isotopic Heterogeneity in Icelandic Basalts

    Science.gov (United States)

    Dixon, E. T.; Honda, M.; McDougall, I.

    2001-01-01

    Two models for generation of heterogeneous He, Ne and Ar isotopic ratios in Icelandic basalts are evaluated using a mixing model and the observed noble gas elemental ratios in Icelandic basalts,Ocean island Basalt (OIBs) and Mid-Ocean Ridge Basalt (MORBs). Additional information is contained in the original extended abstract.

  7. Basalt waste added to Portland cement

    Directory of Open Access Journals (Sweden)

    Thiago Melanda Mendes

    2016-08-01

    Full Text Available Portland cement is widely used as a building material and more than 4.3 billion tons were produced in 2014, with increasing environmental impacts by this industry, mainly through CO2 emissions and consumption of non-removable raw materials. Several by-products have been used as raw materials or fuels to reduce environmental impacts. Basaltic waste collected by filters was employed as a mineral mixture to Portland cement and two fractions were tested. The compression strength of mortars was measured after 7 days and Scanning Electron Microscopy (SEM and Electron Diffraction Scattering (EDS were carried out on Portland cement paste with the basaltic residue. Gains in compression strength were observed for mixtures containing 2.5 wt.% of basaltic residue. Hydration products observed on surface of basaltic particles show the nucleation effect of mineral mixtures. Clinker substitution by mineral mixtures reduces CO2 emission per ton of Portland cement.

  8. Naming Lunar Mare Basalts: Quo Vadimus Redux

    Science.gov (United States)

    Ryder, G.

    1999-01-01

    Nearly a decade ago, I noted that the nomenclature of lunar mare basalts was inconsistent, complicated, and arcane. I suggested that this reflected both the limitations of our understanding of the basalts, and the piecemeal progression made in lunar science by the nature of the Apollo missions. Although the word "classification" is commonly attached to various schemes of mare basalt nomenclature, there is still no classification of mare basalts that has any fundamental grounding. We remain basically at a classification of the first kind in the terms of Shand; that is, things have names. Quoting John Stuart Mill, Shand discussed classification of the second kind: "The ends of scientific classification are best answered when the objects are formed into groups respecting which a greater number of propositions can be made, and those propositions more important than could be made respecting any other groups into which the same things could be distributed." Here I repeat some of the main contents of my discussion from a decade ago, and add a further discussion based on events of the last decade. A necessary first step of sample studies that aims to understand lunar mare basalt processes is to associate samples with one another as members of the same igneous event, such as a single eruption lava flow, or differentiation event. This has been fairly successful, and discrete suites have been identified at all mare sites, members that are eruptively related to each other but not to members of other suites. These eruptive members have been given site-specific labels, e.g., Luna24 VLT, Apollo 11 hi-K, A12 olivine basalts, and Apollo 15 Green Glass C. This is classification of the first kind, but is not a useful classification of any other kind. At a minimum, a classification is inclusive (all objects have a place) and exclusive (all objects have only one place). The answer to "How should rocks be classified?" is far from trivial, for it demands a fundamental choice about nature

  9. Hydrothermal evolution of repository groundwaters in basalt

    International Nuclear Information System (INIS)

    Apps, J.A.

    1984-01-01

    Groundwaters in the near field of a radioactive waste repository in basalt will change their chemical composition in response to reactions with the basalt. These reactions will be promoted by the heat generated by the decaying waste. It is important to predict both the rate and the extent of these reactions, and the secondary minerals produced, because the alteration process controls the chemical environment affecting the corrosion of the canister, the solubility and complexation of migrating radionuclides, the reactivity of the alteration products to radionuclides sorption, and the porosity and permeability of the host rock. A comprehensive review of the literature leads to the preliminary finding that hydrothermally altering basalts in geothermal regions such as Iceland lead to a secondary mineralogy and groundwater composition similar to that expected to surround a repository. Furthermore, laboratory experiments replicating the alteration conditions approximate those observed in the field and expected in a repository. Preliminary estimates were made of the rate of hydration and devitrification of basaltic glass and the zero-order dissolution rate of basaltic materials. The rates were compared with those for rhyolitic glasses and silicate minerals. Preliminary calculations made of mixed process alteration kinetics, involving pore diffusion and surface reaction suggest that at temperatures greater than 150 0 C, alteration proceeds so rapidly as to become pervasive in normally fractured basalt exposed to higher temperatures in the field. 70 references

  10. Continental basalts record the crust-mantle interaction in oceanic subduction channel: A geochemical case study from eastern China

    Science.gov (United States)

    Xu, Zheng; Zheng, Yong-Fei

    2017-09-01

    Continental basalts, erupted in either flood or rift mode, usually show oceanic island basalts (OIB)-like geochemical compositions. Although their depletion in Sr-Nd isotope compositions is normally ascribed to contributions from the asthenospheric mantle, their enrichment in large ion lithophile elements (LILE) and light rare earth elements (LREE) is generally associated with variable enrichments in the Sr-Nd isotope compositions. This indicates significant contributions from crustal components such as igneous oceanic crust, lower continental crust and seafloor sediment. Nevertheless, these crustal components were not incorporated into the mantle sources of continental basalts in the form of solidus rocks. Instead they were processed into metasomatic agents through low-degree partial melting in order to have the geochemical fractionation of the largest extent to achieve the enrichment of LILE and LREE in the metasomatic agents. Therefore, the mantle sources of continental basalts were generated by metasomatic reaction of the depleted mid-ocean ridge basalts (MORB) mantle with hydrous felsic melts. Nevertheless, mass balance considerations indicate differential contributions from the mantle and crustal components to the basalts. While the depleted MORB mantle predominates the budget of major elements, the crustal components predominate the budget of melt-mobile incompatible trace elements and their pertinent radiogenic isotopes. These considerations are verified by model calculations that are composed of four steps in an ancient oceanic subduction channel: (1) dehydration of the subducting crustal rocks at subarc depths, (2) anataxis of the dehydrated rocks at postarc depths, (3) metasomatic reaction of the depleted MORB mantle peridotite with the felsic melts to generate ultramafic metasomatites in the lower part of the mantle wedge, and (4) partial melting of the metasomatites for basaltic magmatism. The composition of metasomatites is quantitatively dictated by

  11. Martian volcanism: festoon-like ridges on terrestrial basalt flows and implications for Mars

    International Nuclear Information System (INIS)

    Theilig, E.; Greeley, R.

    1987-01-01

    The Fink and Fletcher, and Fink model was used to assess and compare flow rheology for two terrestrial basalt flows and one Martian flow with previous studies. Based on the morphologic similarities between the Martian flows and the Icelandic flows and knowledge of the emplacement of the terrestrial flows, the flows west of Arsia Mons are considered to have been emplaced as large sheet flows from basaltic flood style eruptions. Festoon ridges represent folding of the surface crust in the last stages of emplacement when viscosities would be high due to cooling. Alternatively, the lava may have had a high crystallinity or was erupted at low temperatures. In addition, increased compressive stress behind halted flow fronts or in ponded areas may have contributed to ridge formation

  12. Some observations on the Miocene foraminifera from Kachchh, Western India

    Digital Repository Service at National Institute of Oceanography (India)

    Jauhri, A.K.; Khare, N.

    The foraminiferal species described from the Miocene sequence exposed at the village Vinjhan of Kachchh are widely distributed in the comparable successions of the Middle East and Greece. They can be used for inter-regional correlation...

  13. Paleofaunal and Environmental Research on Miocene Fossil Sites TVOR SE and TVOR S on Fort Polk, Louisiana, with Continued Survey, Collection, Processing, and Documentation of other Miocene Localities

    National Research Council Canada - National Science Library

    Schiebout, Judith

    2004-01-01

    Focus of paleontological research on the Miocene of Fort Polk is currently the marine locality TVOR SE, which also has yielded large and small terrestrial Miocene vertebrates, and a single Cretaceous...

  14. Goethite (U–Th)/He geochronology and precipitation mechanisms during weathering of basalts

    OpenAIRE

    Riffel, Silvana B.; Vasconcelos, Paulo M.; Carmo, Isabela O.; Farley, Kenneth A.

    2016-01-01

    (U–Th)/He geochronology of 33 goethite grains from in situ ferruginous duricrusts overlying the Paraná flood basalt in the Guarapuava region, Paraná, Brazil, reveals ages ranging from 3.6 ± 0.4 to 0.4 ± 0.1 Ma. Thirty-one grains from detrital fragments of ferruginous duricrust yield ages in the 6.2 ± 0.6 to 0.7 ± 0.1 Ma range. The results show that goethites from detrital blocks are generally older than those from the in situ ferruginous layers and that all the goethites from the Guarapuava s...

  15. Implications of one-year basalt weathering/reactivity study for a basalt repository environment

    International Nuclear Information System (INIS)

    Pine, G.L.; Jantzen, C.M.

    1987-03-01

    The Savannah River Laboratory is testing the performance of the Defense Waste Processing Facility glass under conditions representing potential repository environments. For a basalt repository, one of the important issues is how rapidly reducing conditions are re-established after placement of the waste. The objective of this study was to examine the factors affecting the reactivity of the basalt. Construction of a nuclear waste repository in basalt will temporarily perturb the groundwater conditions, creating more oxidizing (air-saturated) conditions than an undisturbed repository system. Reducing conditions can be beneficial to the performance of waste glass and canisters, and may limit the transport of certain radionuclides. The Basalt Waste Isolation Project intends to use a backfill containing crushed basalt to re-establish the reducing conditions of the groundwater. The reactivity of the basalt has been found to be minimal once the fresh crushed surfaces have been weathered and the reactive intergranular glass component has been leached, e.g., by long-term surface storage. Crushing of the basalt for pneumatic emplacement of the backfill should, therefore, occur shortly before placement in the repository. This backfill must contain a minimum of 5 percent reactive fines (<100 mesh), to rapidly achieve reducing conditions. 23 refs., 21 figs., 18 tabs

  16. Vapor deposition in basaltic stalactites, Kilauea, Hawaii

    Science.gov (United States)

    Baird, A. K.; Mohrig, D. C.; Welday, E. E.

    Basaltic stalacties suspended from the ceiling of a large lava tube at Kilauea, Hawaii, have totally enclosed vesicles whose walls are covered with euhedral FeTi oxide and silicate crystals. The walls of the vesicles and the exterior surfaces of stalactites are Fe and Ti enriched and Si depleted compared to common basalt. Minerals in vesicles have surface ornamentations on crystal faces which include alkali-enriched, aluminosilicate glass(?) hemispheres. No sulfide-, chloride-, fluoride-, phosphate- or carbonate-bearing minerals are present. Minerals in the stalactites must have formed by deposition from an iron oxide-rich vapor phase produced by the partial melting and vaporization of wall rocks in the tube.

  17. Hardness of basaltic glass-ceramics

    DEFF Research Database (Denmark)

    Jensen, Martin; Smedskjær, Morten Mattrup; Estrup, Maja

    2009-01-01

    The dependence of the hardness of basaltic glass-ceramics on their degree of crystallisation has been explored by means of differential scanning calorimetry, optical microscopy, x-ray diffraction, and Vickers indentation. Different degrees of crystallisation in the basaltic glasses were achieved...... by varying the temperature of heat treatment. The predominant crystalline phase in the glass was identified as augite. It was found that the hardness of the glass phase decreased slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreased....

  18. Isotopic signature of Madeira basaltic magmatism

    International Nuclear Information System (INIS)

    Kogarko, L.N.; Karpenko, S.F.; Bibikova, E.V.; Mato, Zh.

    2000-01-01

    Chemical composition of the basalts of Madeira Island is studied. To assess the isotopic sources of magmatism the Pb-Sr, Sm-Nd, U-Th-Pb systems were investigated in a number of basalts. It is shown that the island's rocks are characterized by the mostly deplet sources in relation to Pb-Sr and Sm-Nd systems ( 87 Sr/ 86 Sr - 0.70282-0.70292, 143 Nd/ 144 Nd - 0.52303-0.51314). Isotopic composition of lead testifies that the magmatism reservoir is some enriched. It is concluded that the magmatism of Madeira Island is a new example of world ocean island's volcanism [ru

  19. Antifriction basalt-plastics based on polypropylene

    Science.gov (United States)

    Bashtannik, P. I.; Ovcharenko, V. G.

    1997-05-01

    A study is made of the dependence of the mechanical and friction-engineering properties of polypropylene reinforced with basalt fibers on the viscosity of the polymer matrix. It is established that the main factors that determine the mechanical properties of the plastics are the quality of impregnation of the fibers by the binder and the residual length of the reinforcing filler in the composite after extrusion and injection molding. The material that was developed has a low friction coefficient and low rate of wear within a relatively brood range of friction conditions. The basalt-plastics can be used in the rubbing parts of machines and mechanisms subjected to dry friction.

  20. Geologic Reconnaissance of the Antelope-Ashwood Area, North-Central Oregon: With Emphasis on the John Day Formation of Late Oligocene and Early Miocene Age

    Science.gov (United States)

    Peck, Dallas L.

    1964-01-01

    This report briefly describes the geology of an area of about 750 square miles in Jefferson, Wasco, Crook, and Wheeler Counties, Oregon. About 16,000 feet of strata that range in age from pre-Tertiary to Quaternary are exposed. These include the following units: pre-Tertiary slate, graywacke, conglomerate, and meta-andesite; Clarno Formation of Eocene age - lava flows, volcanic breccia, tuff, and tuffaceous mudstone, chiefly of andesitic composition; John Day Formation of late Oligocene and early Miocene age - pyroclastic rocks, flows, and domes, chiefly of rhyolitic composition; Columbia River Basalt of middle Miocene age - thick, columnar jointed flows of very fine grained dense dark-gray basalt; Dalles Formation of Pliocene age - bedded tuffaceous sandstone, siltstone, and conglomerate; basalt of Pliocene or Pleistocene age - lava flows of porous-textured olivine basalt; and Quaternary loess, landslide debris, and alluvium. Unconformities separate pre-Tertiary rocks and Clarno Formation, Clarno and John Day Formations, John Day Formation and Columbia River Basalt, and Columbia River Basalt and Dalles Formation. The John Day Formation, the only unit studied in detail, consists of about 4,000 feet of tuff, lapilli tuff, strongly to weakly welded rhyolite ash flows, and less abundant trachyandesite flows and rhyolite flows and domes. The formation was divided into nine mappable members in part of the area, primarily on the basis of distinctive ledge-forming welded ash-flow sheets. Most of the sheets are composed of stony rhyolite containing abundant lithophysae and sparse phenocrysts. One sheet contains 10 to 20 percent phenocrysts, mostly cryptoperthitic soda sanidine, but including less abundant quartz, myrmekitic intergrowths of quartz and sanidine, and oligoclase. The rhyolitic ash flows and lava flows were extruded from nearby vents, in contrast to some of the interbedded air-fall tuff and lapilli tuff of dacitic and andesitic composition that may have been

  1. Increased corrosion resistance of basalt reinforced cement compositions with nanosilica

    Directory of Open Access Journals (Sweden)

    URKHANOVA Larisa Alekseevna

    2014-08-01

    Full Text Available Disperse fiber reinforcement is used to improve deformation and shrinkage characteristics, flexural strength of concrete. Basalt roving and thin staple fiber are often used as mineral fibers. The paper considers the problems of using thin basalt fiber produced by centrifugal-blow method. Evaluation of the corrosion resistance of basalt fiber as part of the cement matrix was performed. Nanodispersed silica produced by electron beam accelerator was used to increase corrosion resistance of basalt fiber.

  2. Investigation of Basalt Woven Fabrics for Military Applications

    Science.gov (United States)

    2011-11-01

    investigates the use of basalt fibers in a composite along with SC-15 epoxy resin for ballistic protection. Basalt fibers are not known as a ballistic...material but rather as a structural one. Even though basalt fibers are not expected to outperform some of the higher ballistic performing materials...such as the aramid and polyethylene fibers ; however, due to the lower manufacturing costs, basalt fibers are an interesting alternative. The objective

  3. Pressure grouting of fractured basalt flows

    International Nuclear Information System (INIS)

    Shaw, P.; Weidner, J.; Phillips, S.; Alexander, J.

    1996-04-01

    This report describes a field trial of pressure grouting in basalt and the results of subsequent coring and permeability measurement activities. The objective was to show that the hydraulic conductivity of fractured basalt bedrock can be significantly reduced by pressure injection of cementitious materials. The effectiveness of the pressure grout procedure was evaluated by measuring the change in the hydraulic conductivity of the bedrock. The extent of grout penetration was established by analyzing postgrout injection drilling chips for the presence of a tracer in the grout and also by examining cores of the treated basalt. Downhole radar mapping was used to establish major lava flow patterns and follow water movement during a surface infiltration test. A site called Box Canyon, which is located northwest of the INEL, was chosen for this study due to the similarity of this surface outcrop geology to that of the underlying bedrock fracture system found at the Radioactive Waste Management Complex. This study showed that hydraulic conductivity of basalt can be reduced through pressure grouting of cementitious material

  4. Site identification presentation: Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1979-11-01

    The final step in the site identification process for the Basalt Waste Isolation Project is described. The candidate sites are identified. The site identification methodology is presented. The general objectives which must be met in selecting the final site are listed. Considerations used in the screening process are also listed. Summary tables of the guidelines used are included

  5. Giant Plagioclase Basalts, eruption rate versus time

    Indian Academy of Sciences (India)

    R.Narasimhan(krishtel emaging) 1461 1996 Oct 15 13:05:22

    I found the GPB lavas to be very interest- ing because in some ... by Venkatesan et al (1993) and thus in a way validates my approach. ... and age calculation of lavas from phenocrysts. Keywords. Deccan Trap; Giant Plagioclase Basalts; eruption duration. Proc. Indian Acad. Sci. (Earth Planet. Sci.), 111, No. 4, December ...

  6. Pressure grouting of fractured basalt flows

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, P.; Weidner, J.; Phillips, S.; Alexander, J.

    1996-04-01

    This report describes a field trial of pressure grouting in basalt and the results of subsequent coring and permeability measurement activities. The objective was to show that the hydraulic conductivity of fractured basalt bedrock can be significantly reduced by pressure injection of cementitious materials. The effectiveness of the pressure grout procedure was evaluated by measuring the change in the hydraulic conductivity of the bedrock. The extent of grout penetration was established by analyzing postgrout injection drilling chips for the presence of a tracer in the grout and also by examining cores of the treated basalt. Downhole radar mapping was used to establish major lava flow patterns and follow water movement during a surface infiltration test. A site called Box Canyon, which is located northwest of the INEL, was chosen for this study due to the similarity of this surface outcrop geology to that of the underlying bedrock fracture system found at the Radioactive Waste Management Complex. This study showed that hydraulic conductivity of basalt can be reduced through pressure grouting of cementitious material.

  7. Petrography of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    Petrographic characteristics of basalts collected from a segment of the Carlsberg Ridge (lat. 3 degrees 35'N to 3 degrees 41'N; long. 64 degrees 05'E to 64 degrees 09'E) show typical pillow lava zonations with variable concentrations of plagioclase...

  8. Effects of Basalt Fibres on Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    El-Gelani A. M.

    2018-01-01

    Full Text Available This paper presents the results of an experimental program carried out to investigate the effects of Basalt Fibre Reinforced Polymers (BFRP on some fundamental mechanical properties of concrete. Basalt fibres are formed by heating crushed basalt rocks and funnelling the molten basalt through a spinneret to form basalt filaments. This type of fibres have not been widely used till recently. Two commercially available chopped basalt fibres products with different aspect ratios were investigated, which are dry basalt (GeoTech Fibre and basalt pre-soaked in an epoxy resin (GeoTech Matrix .The experimental work included compression tests on 96 cylinders made of multiple batches of concrete with varying amounts of basalt fibre additives of the two mentioned types, along with control batches containing no fibres. Furthermore, flexural tests on 24 prisms were carries out to measure the modulus of rupture, in addition to 30 prisms for average residual strength test. Results of the research indicated that use of basalt fibres has insignificant effects on compressive strength of plain concrete, where the increase in strength did not exceed about 5%. On the other hand, results suggest that the use of basalt fibres may increase the compressive strength of concrete containing fly as up top 40%. The rupture strength was increased also by 8% to 28% depending on mix and fibre types and contents. Finally, there was no clear correlation between the average residual strength and ratios of basalt fibres mixed with the different concrete batches.

  9. Geochemical characteristics of the Jos-Plateau Basalts, North ...

    African Journals Online (AJOL)

    The Jos Plateau basalts, present Zr/Nb ratios (2.4-3.0) comparable to those of the alkali basalts of the lower Benue valley, and of the Cameroon volcanic line, suggesting that they were possibly derived from the same mantle source. Keywords: Jos Plateau, alkali basalt, mantle, partial melting, incompatible elements.

  10. Petrology of basalts from Loihi Seamount, Hawaii

    Science.gov (United States)

    Hawkins, James; Melchior, John

    1983-12-01

    Loihi Seamount is the southeasternmost active volcano of the Emperor-Hawaii linear volcanic chain. It comprises a spectrum of basalt compositional varieties including basanite, alkali basalt, transitional basalt and tholeiite. Samples from four dredge collections made on Scripps Institution of Oceanography Benthic Expedition in October 1982 are tholeiite. The samples include highly vesicular, olivine-rich basalt and dense glass-rich pillow fragments containing olivine and augite phenocrysts. Both quartz-normative and olivine-normative tholeiites are present. Minor and trace element data indicate relatively high abundances of low partition coefficient elements (e.g., Ti, K, P. Rb, Ba, Zr) and suggest that the samples were derived by relatively small to moderate extent of partial melting, of an undepleted mantle source. Olivine composition, MgO, Cr and Ni abundances, and Mg/(Mg+Fe), are typical of moderately fractionated to relatively unfractionated "primary" magmas. The variations in chemistry between samples cannot be adequately explained by low-pressure fractional crystallization but can be satisfied by minor variations in extent of melting if a homogeneous source is postulated. Alternatively, a heterogeneous source with variable abundances of certain trace elements, or mixing of liquids, may have been involved. Data for 3He/ 4He, presented in a separate paper, implies a mantle plume origin for the helium composition of the Loihi samples. There is little variation in the helium isotope ratio for samples having different compositions and textures. The helium data are not distinctive enough to unequivocally separate the magma sources for the tholeiitic rocks from the other rock types such as Loihi alkalic basalts and the whole source region for Loihi may have a nearly uniform helium compositions even though other element abundances may be variable. Complex petrologic processes including variable melting, fractional crystallization and magma mixing may have blurred

  11. Flooding and Schools

    Science.gov (United States)

    National Clearinghouse for Educational Facilities, 2011

    2011-01-01

    According to the Federal Emergency Management Agency, flooding is the nation's most common natural disaster. Some floods develop slowly during an extended period of rain or in a warming trend following a heavy snow. Flash floods can occur quickly, without any visible sign of rain. Catastrophic floods are associated with burst dams and levees,…

  12. Paleocene-middle Miocene flexural-margin migration of the non marine llanos Foreland basin of Colombia

    International Nuclear Information System (INIS)

    Bayona, German; Jaramillo, Carlos; Rueda, Milton; Reyes Harker, Andres; Torres, Vladimir

    2007-01-01

    A foreland basin is a dynamic system whose depositional systems migrate in response to changes in tectonic uplift patterns, sedimentary filling processes and isostatic rebound of the lithosphere. The Paleocene-middle Miocene foreland system of the llanos foothills and llanos basin of Colombia includes regional unconformities, abrupt changes in lithology/stacking patterns and flooding surfaces bounding reservoir and seal units. Here we integrate a systematic biostratigraphic study, strata architecture and tectonic subsidence analyses, regional seismic profiles, and provenance data to define the diachronism of such surfaces and to document the direction of migration of foreland depozones. Line a flexural-deformed basin, sandstone composition, rates of accommodation and sediment supply vary across and along the basin. we show how a coeval depositional profile in the llanos foothills-llanos foreland basin consists of lithoranites inter b edded with mudstones (seal rock, supplied from the orogenic front to the west) that correlate craton ward with organic-rich mudstones and coal (source rock), and to amalgamated fluvial-estuarine quartzarenites (reservoir rock, supplied from the craton to the east) adjacent to a sub-aerial fore-bulge (unconformity). This system migrated northward and eastward during the Paleocene, westward during the early-middle Eocene, and eastward during the Oligocene. In the lower-middle Miocene succession of the llanos basin, identification of flooding events indicates a westward encroaching of a shallow-water lacustrine system that covered an eastward-directed fluvial-deltaic system. A similar process has been documented in other basins in Venezuela and Bolivia, indicating the regional extent of such flooding event may be related to the onset of Andean-scale mountain-building processes

  13. Contemporaneous alkaline and calc-alkaline series in Central Anatolia (Turkey): Spatio-temporal evolution of a post-collisional Quaternary basaltic volcanism

    Science.gov (United States)

    Dogan-Kulahci, Gullu Deniz; Temel, Abidin; Gourgaud, Alain; Varol, Elif; Guillou, Hervé; Deniel, Catherine

    2018-05-01

    strength elements (HFSE; Y, Yb) and the La/Nb >1 favor a shallow lithospheric source for ES, HS, OZ and KA basaltic volcanic rocks, whereas some samples bear the trace element signature of an asthenospheric mantle source. The lithospheric mantle beneath Central Anatolia may have not been affected from asthenospheric mantle directly. Negative Nb-Ta-Ti anomalies and a positive Pb spike of ES, HS, OZ and KA may be ascribed to crustal contamination or as the imprints of the previous subduction processes. According to this study, and previous studies, the effect of subduction and/or crustal contamination in Central Anatolia decreased from the Miocene to the Quaternary, and the origin of the Quaternary basaltic rocks mainly derived from subduction-related magmas enriched with sediment input rather than to slab-derived fluids. Our calculated eruption ages for the four basaltic complexes show that spatial differences predominate, whereas temporal trends are difficult to discern due to limited age resolution. According to the available geochronological, petrological and geochemical data, alkaline and calc-alkaline volcanism occurred simultaneously from distinct parental magmas.

  14. Additive Construction using Basalt Regolith Fines

    Science.gov (United States)

    Mueller, Robert P.; Sibille, Laurent; Hintze, Paul E.; Lippitt, Thomas C.; Mantovani, James G.; Nugent, Matthew W.; Townsend, Ivan I.

    2014-01-01

    Planetary surfaces are often covered in regolith (crushed rock), whose geologic origin is largely basalt. The lunar surface is made of small-particulate regolith and areas of boulders located in the vicinity of craters. Regolith composition also varies with location, reflecting the local bedrock geology and the nature and efficiency of the micrometeorite-impact processes. In the lowland mare areas (suitable for habitation), the regolith is composed of small granules (20 - 100 microns average size) of mare basalt and volcanic glass. Impacting micrometeorites may cause local melting, and the formation of larger glassy particles, and this regolith may contain 10-80% glass. Studies of lunar regolith are traditionally conducted with lunar regolith simulant (reconstructed soil with compositions patterned after the lunar samples returned by Apollo). The NASA Kennedy Space Center (KSC) Granular Mechanics & Regolith Operations (GMRO) lab has identified a low fidelity but economical geo-technical simulant designated as Black Point-1 (BP-1). It was found at the site of the Arizona Desert Research and Technology Studies (RATS) analog field test site at the Black Point lava flow in adjacent basalt quarry spoil mounds. This paper summarizes activities at KSC regarding the utilization of BP-1 basalt regolith and comparative work with lunar basalt simulant JSC-1A as a building material for robotic additive construction of large structures. In an effort to reduce the import or in-situ fabrication of binder additives, we focused this work on in-situ processing of regolith for construction in a single-step process after its excavation. High-temperature melting of regolith involves techniques used in glassmaking and casting (with melts of lower density and higher viscosity than those of metals), producing basaltic glass with high durability and low abrasive wear. Most Lunar simulants melt at temperatures above 1100 C, although melt processing of terrestrial regolith at 1500 C is not

  15. Basalts of the Khodzhirbulak Suite and Assessment their Feasibility for Basalt Fiber (Surkhantau Mountains, Southwestern Shoots of the Hissar Ridge

    Directory of Open Access Journals (Sweden)

    N. M. Khakberdyev

    2017-06-01

    Full Text Available The results of preliminary assessment of basalt of the Khodzhirbulakskoy Suite of Surkhantau Mountains for the basalt fiber production are presented. According to petrographic study, the rocks are described as basalts of amygdaloidal structure. On the base of content of the amount of glassy form and nodular calcite, three groups of basalts were identified. The inverse relationship between the bulk content of the volcanic rock and the content of calcite: the greater volume of volcanic rocks, the less content of calcite, and vice versa. The basalt material demonstrates average pH module of 3.52.

  16. Oligo-Miocene peatland ecosystems of the Gippsland Basin and modern analogues

    Science.gov (United States)

    Korasidis, Vera A.; Wallace, Malcolm W.; Wagstaff, Barbara E.; Holdgate, Guy R.

    2017-02-01

    A detailed examination of the brown coal facies preserved in the Latrobe Valley Morwell 1B seam indicates that the type of peat-forming environment and the associated hydrological regime are the main factors influencing the development of lithotypes in brown coal deposits. New palynological data from the Morwell 1B seam suggests that each respective lithotype in the lightening-upwards lithotype cycles was deposited in a particular depositional environment that was characterised by a distinct floral community. The laminated dark lithotype represents a fire-prone emergent marsh that grew on the margins of a coastal lagoon and/or freshwater swamp. This facies grades into the dark lithotype, representing the transition from a meadow marsh to a periodically flooded ombrogenous forested bog. The medium and lighter lithotypes are interpreted as being deposited in an angiosperm-dominated ombrogenous forest bog that was intolerant of fire. These peat-forming environments are interpreted as being largely controlled by moisture and relative depth to water table. Each environment produces distinct lithotypes and lightening-upwards cycles are interpreted as terrestrialization cycles. As the peat grew upwards and above the water table, less moist conditions prevailed and lighter lithotypes were produced. The observed change in colour, from darker to lighter lithotypes, results from the environment evolving from anaerobic/inundated to less anaerobic/less moist settings via terrestrialization. The thin and laterally extensive light and pale lithotypes that top the cycles are interpreted to represent a residual layer of concentrated, oxidation resistant peat-forming elements that result from intense weathering and aerobic degradation of the peats. At a generic level, modern lowland bogs of South Westland in New Zealand have remarkably similar floral/ecological gradients to those of the Oligo-Miocene Morwell 1B brown coal cycles in Australia. This suggests that modern New Zealand

  17. Stratigraphy, composition and form of the Deccan Basalts, Western Ghats, India

    Science.gov (United States)

    Beane, J. E.; Turner, C. A.; Hooper, P. R.; Subbarao, K. V.; Walsh, J. N.

    1986-02-01

    In the Western Ghats between latitudes 18° 20' N and 19° 15' N, 7000 km2 of Deccan Basalt have been mapped with the primary objective of establishing a flow stratigraphy as a guide to the volcanic history of the flood basalts. Using over 70 measured vertical sections, major and trace element analyses of nearly 1200 samples, and rare-earth and87Sr/86Sr determinations for over 60 samples, we divide the basalt into three subgroups and ten formations. In this paper we describe the seven principal formations in the area and the most prominent individual flows. The Kalsubai Subgroup is formed by the lower five formations, the Jawhar, Igatpuri, Neral, Thakurvadi, and Bhimashankar formations, from botton to top. In these formations amygdaloidal compound flows predominate and have a typically high MgO content, including picrite basalt (> 10% MgO) and picrite (> 18% MgO) with phenocrysts of olivine and clinopyroxene. These flows are separated by others which contain giant plagioclase phenocrysts and have more evolved chamical compositions. The Lonavala Subgroup overlies the Kalsubai and is composed of two formations, the Khandala and the Bushe. Both are readily recognized in the field and by their chemical compositions. The Wai Subgroup includes the upper three formations, the Poladpur, the Ambenali, and the Mahabaleshwar. The whole subgroup is composed of simple flows with well-developed flow tops, small phenocrysts of plagioclase, pyroxene and olivine, and relatively evolved bulk compositions. Distribution and variation in thickness of the straitigraphic units within the Western Ghats provide a first comprehensive view of the development of the Deccan volcanic edifice. The persistent southerly dip and gentle southerly plunging anticlinal form of the flows, the lensoid shape of many of the formations, and nearly randomly oriented feeder-dike system are together interpreted as evidence of a central volcanic edifice formed as the Indian plate drifted northward over a mantle

  18. Structural relaxation in annealed hyperquenched basaltic glasses

    DEFF Research Database (Denmark)

    Guo, Xiaoju; Mauro, John C.; Potuzak, M.

    2012-01-01

    The enthalpy relaxation behavior of hyperquenched (HQ) and annealed hyperquenched (AHQ) basaltic glass is investigated through calorimetric measurements. The results reveal a common onset temperature of the glass transition for all the HQ and AHQ glasses under study, indicating that the primary...... relaxation is activated at the same temperature regardless of the initial departure from equilibrium. The analysis of secondary relaxation at different annealing temperatures provides insights into the enthalpy recovery of HQ glasses....

  19. Technical program plan, Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1979-12-01

    The Basalt Waste Isolation Project (BWIP) program as administered by the DOE's Richland Operations Office and Rockwell Hanford Operations is described. The objectives, scope and scientific technologies are discussed. The work breakdown structure of the project includes: project management and support, systems integration, geosciences, hydrology, engineered barriers, test facility design and construction, engineering testing, repository studies, and schedules. The budget of the program including operating and capital cost control is also included

  20. Gamma radiolysis effects on basalt groundwater

    International Nuclear Information System (INIS)

    Gray, W.J.

    1983-10-01

    Gamma radiolysis of basalt groundwater containing 700 ppM methane produces a milky liquid that is a suspension of fine particles of a high molecular weight hydrocarbon somewhat like polyethylene. The ability of these polymers to chelate with, or otherwise sorb, metal ions from aqueous solution was measured using Cu +2 as a representative cation. Values in the range 0.3 to 0.8 millimoles of Cu per liter of solution were found. 5 references, 2 figures, 2 tables

  1. Iron isotopic systematics of oceanic basalts

    Science.gov (United States)

    Teng, Fang-Zhen; Dauphas, Nicolas; Huang, Shichun; Marty, Bernard

    2013-04-01

    The iron isotopic compositions of 93 well-characterized basalts from geochemically and geologically diverse mid-ocean ridge segments, oceanic islands and back arc basins were measured. Forty-three MORBs have homogeneous Fe isotopic composition, with δ56Fe ranging from +0.07‰ to +0.14‰ and an average of +0.105 ± 0.006‰ (2SD/√n, n = 43, MSWD = 1.9). Three back arc basin basalts have similar δ56Fe to MORBs. By contrast, OIBs are slightly heterogeneous with δ56Fe ranging from +0.05‰ to +0.14‰ in samples from Koolau and Loihi, Hawaii, and from +0.09‰ to +0.18‰ in samples from the Society Islands and Cook-Austral chain, French Polynesia. Overall, oceanic basalts are isotopically heavier than mantle peridotite and pyroxenite xenoliths, reflecting Fe isotope fractionation during partial melting of the mantle. Iron isotopic variations in OIBs mainly reflect Fe isotope fractionation during fractional crystallization of olivine and pyroxene, enhanced by source heterogeneity in Koolau samples.

  2. AEGIS methodology demonstration: case example in basalt

    International Nuclear Information System (INIS)

    Dove, F.H.

    1982-01-01

    The AEGIS technology has been successfully demonstrated. For the same data, similar unpublished results have been obtained by RHO and INTERA Environmental Consultants, Inc. for contaminant transport. In addition to establishing the utility of computer codes and assessment methodology, the AEGIS technology demonstration in basalt has also produced some practical guidance for future field data gathering programs. The results of this basalt demonstration indicate that the geohydrologic systems separating the nuclear waste from the natural biosphere discharge site mitigate the consequences of the postulated fault intersection event. This analysis suggests that the basalt system satisfies the 1000- and 10,000-yr proposed standards for release to the accessible environment (limited release of 129 I and 14 C). The reader should be cautioned, however, that the results are valid only for one particular set of parameters and one postulated release scenario. A complete sensitivity analysis must be performed to evaluate the range of effects that might be observed under different release conditions and for the different range in parameters

  3. Hydrologic modeling of the Columbia Plateau basalts

    International Nuclear Information System (INIS)

    Dove, F.H.; Cole, C.R.; Bond, F.W.; Zimmerman, D.A.

    1982-09-01

    The Office of Nuclear Waste Isolation (ONWI) directed the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program to conduct a technology demonstration of current performance assessment techniques for the Department of Energy (DOE) as applied to a nuclear waste repository in the Columbia Plateau Basalts. Hypothetical repository coordinates were selected for an actual geographical setting on the Hanford Reservation in the state of Washington. Published hydrologic and geologic data used in the analyses were gathered in 1979 or earlier. The hydrologic simulation was divided into three major parts: (1) aquifer recharge calculations, (2) a regional hydrologic model, and (3) a local hydrologic model of the Pasco Basin. The presentation discusses the regional model. An estimate of the amount of water transmitted through the groundwater system was required to bound the transmissivity values and to estimate the transmissivity distributions for the deeper basalts. The multiple layer two-dimensional Variable Thickness Transient (VTT) code was selected as appropriate for the amount of data available and for the conditions existing in the regional systems. This model uses a finite difference formulation to represent the partial differential flow equation. The regional study area as defined for the VTT model was divided into 55 by 55 square pattern with each grid 5 kilometers on a side. The regional system was modeled as a held potential surface layer and two underlying basalt layers. The regional model established the boundary conditions for the hydrologic model the Pasco Basin

  4. Climate aberrations during the middle Miocene: evidence from the eastern North Atlantic Ocean

    NARCIS (Netherlands)

    Quaijtaal, W.; Donders, T.H.; Schouten, S.; Louwye, S.

    2013-01-01

    During the Middle Miocene Climatic Optimum (MMCO; 17-14.5 Ma) the relatively warm climate of the Miocene reached peak temperatures. After the MMCO, the global climate started cooling through several short-lived cooling events, represented by positive oxygen isotope excursions: the Mi-events (Miocene

  5. Basalt Reactivity Variability with Reservoir Depth in Supercritical CO2 and Aqueous Phases

    Energy Technology Data Exchange (ETDEWEB)

    Schaef, Herbert T.; McGrail, B. Peter; Owen, Antionette T.

    2011-04-01

    Long term storage of CO{sub 2} in geologic formations is currently considered the most attractive option to reduce greenhouse gas emissions while continuing to utilize fossil fuels for energy production. Injected CO{sub 2} is expected to reside as a buoyant water-saturated supercritical fluid in contact with reservoir rock, the caprock system, and related formation waters. As was reported for the first time at the GHGT-9 conference, experiments with basalts demonstrated surprisingly rapid carbonate mineral formation occurring with samples suspended in the scCO{sub 2} phase. Those experiments were limited to a few temperatures and CO{sub 2} pressures representing relatively shallow (1 km) reservoir depths. Because continental flood basalts can extend to depths of 5 km or more, in this paper we extend the earlier results across a pressure-temperature range representative of these greater depths. Different basalt samples, including well cuttings from the borehole used in a pilot-scale basalt sequestration project (Eastern Washington, U.S.) and core samples from the Central Atlantic Magmatic Province (CAMP), were exposed to aqueous solutions in equilibrium with scCO{sub 2} and water-rich scCO{sub 2} at six different pressures and temperatures for select periods of time (30 to 180 days). Conditions corresponding to a shallow injection of CO{sub 2} (7.4 MPa, 34 C) indicate limited reactivity with basalt; surface carbonate precipitates were not easily identified on post-reacted basalt grains. Basalts exposed under identical times appeared increasingly more reacted with simulated depths. Tests, conducted at higher pressures (12.0 MPa) and temperatures (55 C), reveal a wide variety of surface precipitates forming in both fluid phases. Under shallow conditions tiny clusters of aragonite needles began forming in the wet scCO{sub 2} fluid, whereas in the CO{sub 2} saturated water, cation substituted calcite developed thin radiating coatings. Although these types of coatings

  6. Palynological Zonation of Oligocene to Early Miocene Sediments of ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-31

    Dec 31, 2017 ... Keywords: Lithozones; Niger delta Basin; Palynomorphs; Oligocene to Early Miocene; Depobelt. The Niger Delta is ... province on the West African continental margin. It lies mainly in the ... Nigeria depends largely on the oil and gas derived from it. ... generation, accumulation and retention of hydrocarbons.

  7. Molluscan fauna from the Miocene sediments of Kachchh, Gujarat ...

    Indian Academy of Sciences (India)

    geological mapping of Kachchh was assigned to. Fedden and Wynne in the late ... Figure 1. Geological map of parts of Kachchh Region, Gujarat State, India; slightly modified after Biswas and Deshpande. Formational boundaries ...... division and correlation of Oligo–Miocene petroleum bearing strata in India and future ...

  8. Avian fossils from the Early Miocene Moghra Formation of Egypt ...

    African Journals Online (AJOL)

    Avian remains from the Early Miocene (~17 Ma) Moghra Formation of Egypt include new records of 'waterbirds' (storks, herons, pelicans and allies) and a ratite. Only a single avian fossil has been previously reported from Wadi Moghra and, thus, additional knowledge of the avifauna complements previously documented ...

  9. Larger benthic foraminifera in Miocene carbonates of Indonesia

    NARCIS (Netherlands)

    Novak, Vibor

    2014-01-01

    Present day Southeast Asia represents the region that supports the most diverse marine ecosystems on Earth. The origin of this biodiversity is still unresolved, but it is proposed to be present at least since the Early Miocene. Therefore, the data acquired from the fossil assemblages may contribute

  10. A southern North Sea Miocene dinoflagellate cyst zonation

    NARCIS (Netherlands)

    Munsterman, D.K.; Brinkhuis, H.

    2004-01-01

    An integrated stratigraphical analysis emphasizing organic-walled dinoflagellate cyst (dinocyst) distribution has been carried out on multiple boreholes penetrating the Miocene in the subsurface of the Netherlands (southern North Sea Basin). The bulk of the investigated successions is attributed to

  11. Two New Mylagaulid Rodents from the Early Miocene of China.

    Directory of Open Access Journals (Sweden)

    Xiaoyu Lu

    Full Text Available Mylagaulid fossorial rodents are a common component of North American Miocene fossil faunas. However outside of North America, only three species are known from Asia. Here we report two new mylagaulids, Irtyshogaulus minor gen. et sp. nov. and Irtyshogaulus major gen. et sp. nov., recovered from early Miocene sediments in the Junggar Basin in northwestern China. The two new taxa are small-sized, high-crowned promylagauline rodents. Their lower molars possess high metastylid crests, small mesostylids, broad and posterolingually expanded labial inflections, and transversely extending metalophid IIs. The mesoconid is absent in both species. The anterior and posterior fossettids are large and equally developed. Their upper M1-2s possess a square occlusal surface with five deep fossettes. The two new taxa are distinguished from each other mainly by their size, the morphology of fossettes and fossettids, development of mesial and distal lophs, posterior reduction of M3, and the orientation of m2 hypolophid. Our phylogenetic analysis indicates that Irtyshogaulus and Lamugaulus (another early Miocene Asian mylagaulid are sister taxa. The two genera are nested among the North American promylagaulines, and share a common ancestor from North America, indicating early Miocene intercontinental dispersal within this clade of rodents.

  12. A Transitional Gundi (Rodentia: Ctenodactylidae from the Miocene of Israel.

    Directory of Open Access Journals (Sweden)

    Raquel López-Antoñanzas

    Full Text Available We describe a new species of gundi (Rodentia: Ctenodactylidae: Ctenodactylinae, Sayimys negevensis, on the basis of cheek teeth from the Early Miocene of the Rotem Basin, southern Israel. The Rotem ctenodactylid differs from all known ctenodactylid species, including Sayimys intermedius, which was first described from the Middle Miocene of Saudi Arabia. Instead, it most resembles Sayimys baskini from the Early Miocene of Pakistan in characters of the m1-2 (e.g., the mesoflexid shorter than the metaflexid, the obliquely orientated hypolophid, and the presence of a strong posterolabial ledge and the upper molars (e.g., the paraflexus that is longer than the metaflexus. However, morphological (e.g., presence of a well-developed paraflexus on unworn upper molars and dimensional (regarding, in particular, the DP4 and M1 or M2 differences between the Rotem gundi and Sayimys baskini distinguish them and testify to the novelty and endemicity of the former. In its dental morphology, Sayimys negevensis sp. nov. shows a combination of both the ultimate apparition of key-characters and incipient features that would be maintained and strengthened in latter ctenodactylines. Thus, it is a pivotal species that bridges the gap between an array of primitive ctenodactylines and the most derived, Early Miocene and later, gundis.

  13. Making rhyolite in a basalt crucible

    Science.gov (United States)

    Eichelberger, John

    2016-04-01

    Iceland has long attracted the attention of those concerned with the origin of rhyolitic magmas and indeed of granitic continental crust, because it presents no alternative for such magmas other than deriving them from a basaltic source. Hydrothermally altered basalt has been identified as the progenitor. The fact that rhyolite erupts as pure liquid requires a process of melt-crustal separation that is highly efficient despite the high viscosity of rhyolite melt. Volcanoes in Iceland are foci of basaltic magma injection along the divergent plate boundary. Repeated injection produces remelting, digestion, and sometimes expulsion or lateral withdrawal of material resulting in a caldera, a "crucible" holding down-dropped and interlayered lava flows, tephras, and injected sills. Once melting of this charge begins, a great deal of heat is absorbed in the phase change. Just 1% change in crystallinity per degree gives a melt-present body an effective heat capacity >5 times the subsolidus case. Temperature is thus buffered at the solidus and melt composition at rhyolite. Basalt inputs are episodic ("fires") so likely the resulting generation of rhyolite by melting is too. If frequent enough to offset cooling between events, rhyolite melt extractions will accumulate as a rhyolite magma reservoir rather than as discrete crystallized sills. Evidently, such magma bodies can survive multiple firings without themselves erupting, as the 1875 eruption of Askja Caldera of 0.3 km3 of rhyolite equilibrated at 2-km depth without previous leakage over a ten-millennium period and the surprise discovery of rhyolite magma at 2-km depth in Krafla suggest. Water is required for melting; otherwise melting cannot begin at a temperature lower than that of the heat source. Because the solubility of water in melt is pressure-dependent and almost zero at surface pressure, there must be a minimum depth at which basalt-induced melting can occur and a rhyolite reservoir sustained. In practice, the

  14. Lithostratigraphy of the Upper Oligocene - Miocene succession of Denmark

    Directory of Open Access Journals (Sweden)

    Piasecki, Stefan

    2010-12-01

    Full Text Available This paper presents a revised lithostratigraphic scheme for the uppermost Upper Oligocene – Miocene succession of Denmark. The marine Oligocene Brejning Clay Member is upgraded to formation status and includes the Sydklint Member and the Øksenrade Member (new. The shallow marine and deltaic deposits of mainly Early Miocene age are included in the Ribe Group (new while the fully marine Middle and Upper Miocene clay-rich deposits are referred to the Måde Group (new. The Ribe Group is subdivided into 6 formations: the Vejle Fjord Formation is revised and includes the Skansebakke Member,the Billund Formation (new includes the Addit and Hvidbjerg Members (new, the Klintinghoved Formation is redefined formally and includes the Koldingfjord Member (new, the Bastrup Formation(new includes the Resen Member (new, the Vandel Member is a new member in the Arnum Formation (revised, the Odderup Formation is redefined and includes the Stauning Member (new and the coalbearing Fasterholt Member. The Måde Group is subdivided into the Hodde, Ørnhøj (new, Gram and Marbæk (new Formations. Subdivision of the Upper Oligocene – Miocene succession into two groups, the Ribe and Måde Groups, is compatible with the North Sea lithostratigraphic framework where they correlate with the upper part of the Hordaland Group and the Nordland Group, respectively. The revised lithostratigraphic framework correlated in three dimensions provides rigorous constraints on the palaeogeographic interpretation of the Late Oligocene – Miocene period. Three major deltaic units (Billund, Bastrup and Odderup Formations prograded from the north and north-east into the North Sea Basin during the Early – early Middle Miocene. Delta progradation was punctuated by deposition of marine clay and silt associated with minor transgressive events (Vejle Fjord, Klintinghoved and Arnum Formations. During the Middle–Late Miocene, marine depositional conditions dominated (Hodde, Ørnhøj and

  15. A major reorganization of Asian climate by the early Miocene

    Directory of Open Access Journals (Sweden)

    Z. T. Guo

    2008-08-01

    Full Text Available The global climate system experienced a series of drastic changes during the Cenozoic. In Asia, these include the climate transformation from a zonal pattern to a monsoon-dominated pattern, the disappearance of typical subtropical aridity, and the onset of inland deserts. Despite major advances in the last two decades in characterizing and understanding these climate phenomena, disagreements persist relative to the timing, behaviors and underlying causes.

    This paper addresses these issues mainly based on two lines of evidence. First, we compiled newly collected data from geological indicators of the Cenozoic environment in China as paleoenvironmental maps of ten intervals. In confirming the earlier observation that a zonal climate pattern was transformed into a monsoonal one, the maps within the Miocene indicate that this change was achieved by the early Miocene, roughly consistent with the onset of loess deposition in China. Although a monsoon-like regime would have existed in the Eocene, it was restricted to tropical-subtropical regions. The latitudinal oscillations of the climate zones during the Paleogene are likely attributable to the imbalance in evolution of polar ice-sheets between the two hemispheres.

    Secondly, we examine the relevant depositional and soil forming processes of the Miocene loess-soil sequences to determine the circulation characteristics with emphasis on the early Miocene. Continuous eolian deposition in the middle reaches of the Yellow River since the early Miocene firmly indicates the formation of inland deserts, which have been constantly maintained during the past 22 Ma. Grain-size gradients between loess sections indicate northerly dust-carrying winds from northern sources, a clear indication of an Asian winter monsoon system. Meanwhile, well-developed Luvisols show evidence that moisture from the oceans reached northern China. This evidence shows the coexistence of two kinds of

  16. The early to mid-Miocene environment of Antarctica

    Science.gov (United States)

    Ashworth, A. C.; Lewis, A.

    2012-12-01

    Paleoecological studies in the Transantarctic Mountains of the McMurdo region provide evidence that the climate was both warmer and wetter in the early to mid-Miocene than it was during the late Miocene. The climate change was accompanied by a shift from wet- to cold-based glaciation in the TAM and the probable growth of the polar ice sheet. Terrestrial and freshwater aquatic fossil assemblages from the Friis Hills (77°S) and the Olympus Range (77°S), with endpoint 40Ar/39Ar ages on tephras of 19.76 Ma and 14.07 Ma, respectively, indicate climatic cooling during the interval. At c.14 Ma, the temperature dropped below the threshold required to support the plants and insects of a tundra biome, and they became extinct. This interpretation is supported by pollen studies from Ross Sea cores. The extinction of the tundra biota on the continent appears to have been time-transgressive, occurring at 12.8 Ma on the Antarctic Peninsula. Evidence of climatic cooling from early to mid-Miocene is based on a decrease in biodiversity. During interglacial phases of the early Miocene, the poorly drained valley of the Friis Hills supported a sexually-reproducing moss community dominated by Campylium cf. polygamum, which today grows on the margins of lakes and in soil between boulders. Wood and leaves of Nothofagus (Southern Beech), and the seeds of at least five other angiosperm species are preserved as fossils. In addition, there are abundant megaspores and spiny, curved leaves of the aquatic lycopod Isoetes (Quillwort), as well as chitinous remains of curculionid beetles and Chironomidae (midges). During glacial phases, the only fossils found are Nothofagus leaves of a species which appears to be different than that associated with the interglacial phases. Pollen supports the interpretation that there was more than one species of Nothofagus in the vegetation. The types and numbers of species indicate that the vegetation was a shrub tundra. The closest modern analog for the fossil

  17. Flood Hazard Area

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  18. Flood Hazard Boundaries

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  19. Base Flood Elevation

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  20. Flood Risk Regional Flood Defences : Technical report

    NARCIS (Netherlands)

    Kok, M.; Jonkman, S.N.; Lendering, K.T.

    2015-01-01

    Historically the Netherlands have always had to deal with the threat of flooding, both from the rivers and the sea as well as from heavy rainfall. The country consists of a large amount of polders, which are low lying areas of land protected from flooding by embankments. These polders require an

  1. High resolution biostratigraphy of Oligo-Miocene Leon and Chama Formations: An integrated approach for sequence stratigraphy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pittelli, R.; Rull, V. (Maraven S.A., Caracas (Venezuela))

    1993-02-01

    Based on foraminiferal and palynological high resolution studies, a set of Sequence Boundaries (SB) and Maximum Flooding Surfaces (MSF) were identified for the Venezuelan Northwestern Andean Foothills Leon and Chama formations. Changes in abundance patterns of forminifera palynomorphs, in faunal/floral composition and distribution, together with quantitative studies of particulate organic matter allowed picking SB 30, 21 and 15.5 (very low values of fossil abundance and faunal discontinuities, recognized by a rapid stratigraphic change in biofacies and faunal assemblage and the associated mineralogical contents) and MFS 18.5, 16, and 15 (abundant fossils). The Leon Formation represents coastal plain and swamp deposits with some minor fluctuations in the seawater level. The top of the Leon Formation shaly unit is bounded by SB 30, according to Hag B.U. et al (version 1992), marked by a decrease in fossil abundance. An increase in faunal/floral content close to the top of the section coincides with the MFS 18.5. The upper part of the formation is marked by a sandy unit with SB 16.5, characterized again by a decrease in fossil abundance at its top. The Chama Formation was deposited in a transitional environment, with minor seawater level fluctuations. Climate type was tropical humid, with seasonal precipitations, except at the Early Miocene arid or semiarid phase. Mangrove and rain forest vegetation dominated throughout the Early to Middle Miocene. MFS 16 was picked on the basis of a high abundance of microforams and glauconite.

  2. Magnetostratigraphy of the Grande Ronde Basalt Pasco Basin, Washington

    International Nuclear Information System (INIS)

    Packer, D.R.; Petty, M.H.

    1979-01-01

    The paleomagnetic measurements of samples from the holes sampled have shown that there are four magnetic correlation lines, between adjacent flows in holes that have distinctly different mean stratigraphic inclinations, and two magnetic polarity boundaries that can be used for magnetic correlation in the Grande Ronde Basalt in the Pasco Basin. The results of paleomagnetic measurements of samples from the Wanapum Basalt and Saddle Mountains Basalt indicate that the potential for magnetostratigraphic correlation in these sequences is also good

  3. Increased corrosion resistance of basalt reinforced cement compositions with nanosilica

    OpenAIRE

    URKHANOVA Larisa Alekseevna; LKHASARANOV Solbon Aleksandrovich; ROZINA Victoria Yevgenievna; BUYANTUEV Sergey Lubsanovich; BARDAKHANOV Sergey Prokopievich

    2014-01-01

    Disperse fiber reinforcement is used to improve deformation and shrinkage characteristics, flexural strength of concrete. Basalt roving and thin staple fiber are often used as mineral fibers. The paper considers the problems of using thin basalt fiber produced by centrifugal-blow method. Evaluation of the corrosion resistance of basalt fiber as part of the cement matrix was performed. Nanodispersed silica produced by electron beam accelerator was used to increase corrosion resistance of ba...

  4. Structural control on basaltic dike and sill emplacement, Paiute Ridge mafic intrusion complex, southern Nevada

    International Nuclear Information System (INIS)

    Carter Krogh, K.E.; Valentine, G.A.

    1996-08-01

    Late Miocene basaltic sills and dikes in the Paiute Ridge area of southern nevada show evidence that their emplacement was structurally controlled. Basaltic dikes in this area formed by dilating pre-existing vertical to steeply E-dipping normal faults. Magma propagation along these faults must have required less energy than the creation of a self-propagated fracture at dike tips and the magma pressure must have been greater than the compressive stress perpendicular to the fault surface. N- to NE-trending en echelon dikes formed locally and are not obviously attached to the three main dikes in the area. The en echelon segments are probably pieces of deeper dikes, which are segmented perhaps as a result of a documented rotation of the regional stresses. Alternatively, changes in orientation of principal stresses in the vicinity of each en echelon dike could have resulted from local loads associated with paleotopographic highs or nearby structures. Sills locally branched off some dikes within 300 m of the paleosurface. These subhorizontal bodies occur consistently in the hanging wall block of the dike-injected faults, and intrude Tertiary tuffs near the Paleozoic-Tertiary contact. The authors suggest that the change in stresses near the earth's surface, the material strength of the tuff and paleozoic rocks, and the Paleozoic bedding dip direction probably controlled the location of sill formation and direction of sill propagation. The two largest sills deflected the overlying tuffs to form lopoliths, indicating that the magma pressure exceeded vertical stresses at that location and that the shallow level and large size of the sills allowed interaction with the free (earth's) surface. 32 refs., 4 figs., 1 tab

  5. Study on basalt fiber parameters affecting fiber-reinforced mortar

    Science.gov (United States)

    Orlov, A. A.; Chernykh, T. N.; Sashina, A. V.; Bogusevich, D. V.

    2015-01-01

    This article considers the effect of different dosages and diameters of basalt fibers on tensile strength increase during bending of fiberboard-reinforced mortar samples. The optimal dosages of fiber, providing maximum strength in bending are revealed. The durability of basalt fiber in an environment of cement, by means of microscopic analysis of samples of fibers and fiberboard-reinforced mortar long-term tests is examined. The article also compares the behavior of basalt fiber in the cement stone environment to a glass one and reveals that the basalt fiber is not subject to destruction.

  6. Miocene magmatism and tectonics within the Peri-Alboran orogen (western Mediterranean)

    Science.gov (United States)

    El Azzouzi, M.; Bellon, H.; Coutelle, A.; Réhault, J.-P.

    2014-07-01

    The aim of this paper concerns Miocene igneous activity in the Alboran Sea and Peri-Alboran area (northern Morocco, western Algeria and Betic Cordilleras in Spain), considering its age and its location with regard to major tectonics structures. We have compiled previous K-Ar isotopic ages of lavas and plutonic boulders and intrusives with an error of ±1σ and completed this set by a new K-Ar isotopic age for andesitic tuffites from Alboran Island. Geochemistry of most of these samples has been considered after previous analyses completed with new data for Spain magmatism. These two sets of data allow us to place the magmatic activity within the regional stratigraphy and tectonics and their chronological framework of the three major tectonic phases of the Maghrebian orogen, at 17 Ma (Burdigalian), 15 Ma (Langhian) and 9 Ma (Tortonian). Petro-geochemical characteristics are compared through time and geographical locations. A major goal of this coupled approach is to help the elaboration of possible geodynamical processes. As an application, we present the case study of the Dellys, Djinet and Thenia region (east of Algiers) where the successive magmatic events between 19.4 ± 1 and 11.6 ± 0.5 Ma are closely related to the local tectonics and sedimentation. The Peri-Alboran igneous activity is placed in a multidisciplinary framework. Timing of activity is defined according to the ages of the neighbouring sedimentary units and the K-Ar ages of igneous rocks. In Spain, the Cabo de Gata-Carboneras magmatic province displays late Oligocene and early Miocene leucogranitic dikes, dated from 24.8 ± 1.3 to 18.1 ± 1.2 Ma; three following andesitic to rhyolitic events took place around 15.1 ± 0.8 to 14.0 ± 0.7 Ma, 11.8 ± 0.6 to 9.4 ± 0.4 Ma, 8.8 ± 0.4 to 7.9 ± 0.4 Ma; this last event displays also granitic rocks. Lamproitic magmas dated between 8.4 ± 0.4 and 6.76 ± 0.04 Ma were emplaced after the Tortonian phase. In Morocco, after the complex building of the Ras Tarf

  7. FOAM CONCRETE REINFORCEMENT BY BASALT FIBRES

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-10-01

    Full Text Available The authors demonstrate that the foam concrete performance can be improved by dispersed reinforcement, including methods that involve basalt fibres. They address the results of the foam concrete modeling technology and assess the importance of technology-related parameters. Reinforcement efficiency criteria are also provided in the article. Dispersed reinforcement improves the plasticity of the concrete mix and reduces the settlement crack formation rate. Conventional reinforcement that involves metal laths and rods demonstrates its limited application in the production of concrete used for thermal insulation and structural purposes. Dispersed reinforcement is preferable. This technology contemplates the infusion of fibres into porous mixes. Metal, polymeric, basalt and glass fibres are used as reinforcing components. It has been identified that products reinforced by polypropylene fibres demonstrate substantial abradability and deformability rates even under the influence of minor tensile stresses due to the low adhesion strength of polypropylene in the cement matrix. The objective of the research was to develop the type of polypropylene of D500 grade that would demonstrate the operating properties similar to those of Hebel and Ytong polypropylenes. Dispersed reinforcement was performed by the basalt fibre. This project contemplates an autoclave-free technology to optimize the consumption of electricity. Dispersed reinforcement is aimed at the reduction of the block settlement in the course of hardening at early stages of their operation, the improvement of their strength and other operating properties. Reduction in the humidity rate of the mix is based on the plasticizing properties of fibres, as well as the application of the dry mineralization method. Selection of optimal parameters of the process-related technology was performed with the help of G-BAT-2011 Software, developed at Moscow State University of Civil Engineering. The authors also

  8. Descriptive summary of the Grande Ronde Basalt type section, Columbia River Basalt Group

    International Nuclear Information System (INIS)

    Camp, V.E.; Price, S.M.; Reidel, S.P.

    1978-10-01

    The Grande Ronde Basalt type section, located in extreme southeastern Washington, was measured, sampled, and characterized. The section is 800 meters thick and is comprised of 35 Grande Ronde Basalt flows. These flows are divisible into 3 magnetostratiographic units termed, in ascending order, the R 1 , the N 1 , and the R 2 . The R 1 unit is represented by 13 reversely polarized flows; the N 1 unit, by 13 normally polarized flows; and the R 2 , by 9 reversely polarized flows. Chemically, the Grande Ronde Basalt flows are divided into 2 major groups, termed A and B. The compositions of the lower 9 flows, members of Group A, are similar to either the high-Mg Grande Ronde chemical type, the high-Ti Grande Ronde chemical type, or the Pomona chemical type. The compositions of the upper 25 flows, members of Group B, are predominantly similar to the low-Mg Grande Ronde chemical type. Petrographically, the Grande Ronde Basalt flows are generally fine grained and aphyric, and have a intergranular or intersertal micro-texture. Major mineral phases include plagioclase (An/sub 40-60/) and augite; minor mineral phases include pigeonite, orthopyroxene, ilmenite, titanomagnetite, and olivine. Group A flows generally contain more olivine and less pigeonite than do Group B flows. 6 figures, 6 tables

  9. Crystal Stratigraphy of Two Basalts from Apollo 16: Unique Crystallization of Picritic Basalt 606063,10-16 and Very-Low-Titanium Basalt 65703,9-13

    Science.gov (United States)

    Donohue, P. H.; Neal, C. R.; Stevens, R. E.; Zeigler, R. A.

    2014-01-01

    A geochemical survey of Apollo 16 regolith fragments found five basaltic samples from among hundreds of 2-4 mm regolith fragments of the Apollo 16 site. These included a high-Ti vitrophyric basalt (60603,10-16) and one very-low-titanium (VLT) crystalline basalt (65703,9-13). Apollo 16 was the only highlands sample return mission distant from the maria (approx. 200 km). Identification of basaltic samples at the site not from the ancient regolith breccia indicates input of material via lateral transport by post-basin impacts. The presence of basaltic rocklets and glass at the site is not unprecedented and is required to satisfy mass-balance constraints of regolith compositions. However, preliminary characterization of olivine and plagioclase crystal size distributions indicated the sample textures were distinct from other known mare basalts, and instead had affinities to impact melt textures. Impact melt textures can appear qualitatively similar to pristine basalts, and quantitative analysis is required to distinguish between the two in thin section. The crystal stratigraphy method is a powerful tool in studying of igneous systems, utilizing geochemical analyses across minerals and textural analyses of phases. In particular, trace element signatures can aid in determining the ultimate origin of these samples and variations document subtle changes occurring during their petrogenesis.

  10. Urban pluvial flood prediction

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Nielsen, Jesper Ellerbæk; Jensen, David Getreuer

    2016-01-01

    Flooding produced by high-intensive local rainfall and drainage system capacity exceedance can have severe impacts in cities. In order to prepare cities for these types of flood events – especially in the future climate – it is valuable to be able to simulate these events numerically both...... historically and in real-time. There is a rather untested potential in real-time prediction of urban floods. In this paper radar data observations with different spatial and temporal resolution, radar nowcasts of 0–2 h lead time, and numerical weather models with lead times up to 24 h are used as inputs...... to an integrated flood and drainage systems model in order to investigate the relative difference between different inputs in predicting future floods. The system is tested on a small town Lystrup in Denmark, which has been flooded in 2012 and 2014. Results show it is possible to generate detailed flood maps...

  11. Commercial nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Hardy, M.P.; Patricio, J.G.; Heley, W.H.

    1980-06-01

    The Basalt Waste Isolation Project (BWIP) is an ongoing research and engineering effort being conducted by Rockwell Hanford Operations (Rockwell), which is under contract to the US Department of Energy. The objectives of this program are to assess the feasibility of and to provide the technology needed to design and construct a licensed commercial nuclear waste repository in the deep basalt formations underlying the Hanford Site. An extensive preconceptual design effort was undertaken during 1979 to develop a feasible concept that could serve as a reference design for both surface and underground facilities. The preconceptual design utilized existing technology to the greatest extent possible to offer a system design that could be utilized in establishing schedule and cost baseline data, recommend alternatives that require additional study, and develop basic design requirements that would allow evolution of the design process prior to the existence of legislated criteria. This paper provides a description of the concept developed for the subsurface aspects of this nuclear waste repository

  12. Preparation of basalt-based glass ceramics

    Directory of Open Access Journals (Sweden)

    MIHOVIL LOGAR

    2003-06-01

    Full Text Available Local and conventional raw materials–massive basalt from the Vrelo locality on Kopaonik mountain–have been used as starting materials to test their suitability for the production of glass-ceramics. Crystallization phenomena of glasses of the fused basalt rocks were studied by X-ray phase analysis, optical microscopy and other techniques. Various heat treatments were used, and their influences, on controlling the microstructures and properties of the products were studied with the aim of developing high strength glass-ceramic materials. Diopside CaMg(SiO32 and hypersthene ((Mg,FeSiO3 were identifies as the crystalline phases. The final products contained considerable amounts of a glassy phase. The crystalline size was in range of 8–480 mm with plate or needle shape. Microhardness, crashing strength and wears resistence of the glass-ceramics ranged from 6.5–7.5, from 2000–6300 kg/cm2 and from 0.1–0.2 g/cm, respectively.

  13. Degassing of reduced carbon from planetary basalts.

    Science.gov (United States)

    Wetzel, Diane T; Rutherford, Malcolm J; Jacobsen, Steven D; Hauri, Erik H; Saal, Alberto E

    2013-05-14

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential.

  14. FLOOD MENACE IN KADUNA METROPOLIS: IMPACTS ...

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    damage, causes of flooding, human response to flooding and severity of ... from moving out. Source of ... Man responds to flood hazards through adjustment, flood abatement ... action to minimize or ameliorate flood hazards; flood abatement.

  15. Formation of early-middle Miocene red beds in the South China Sea: element geochemistry and mineralogy analysis

    Science.gov (United States)

    Lyu, X.; Liu, Z.

    2017-12-01

    The formation of oceanic red beds that usually present oxic and oligotrophic conditions with low sedimentation rate has been used to trace depositional paleoenvironment and paleoclimate change. Red beds overlying oceanic basalts were drilled at two adjacent Sites U1433 and U1434 of IODP Expedition 349 in the Southwest Subbasin of the South China Sea. The occurrence of early-middle Miocene red beds may indicate that at that time there was oxic and quiet marine environment in the deep South China Sea. To understand their formation of red-color, local depositional condition, and potential paleoceanographic significance, major elements (XRF), trace and rare earth elements (ICP-MS), Fe chemical speciation (modified sequential iron extraction procedure), and Fe oxic minerals (CBD and DRS) were analyzed. Geochemical and mineralogical data reveal that hematite and goethite are responsible for the reddish color and red beds were deposited under highly oxic, oligotrophic conditions with a little later hydrothermal influence in the South China Sea. Our results indicate that: (1) after treatment using the CBD procedure, the red samples presented a change in color to greenish, showing the iron oxides being responsible for the sediment color; (2) enriched Mn, depleted U, S enrichment factors, and negative Ce anomaly show that the water mass was pre-oxidized before transported to the study location; (3) low primary productivity was inferred from the lower P, Ba enrichment factors in red beds compared to non-red beds; (4) the excess Mo influx at the bottom may come from the later hydrothermal input; (5) the diverse Ca enrichment factors and correlations between Fe and Al suggest different allogenic sources for red beds at our two sites. We conclude that the red beds at Sites U1433 and U1434 despite their diverse sources both developed in externally oxidized water mass and low primary productivity conditions, and partially altered by hydrothermal fluids after their pelagic

  16. Exceptional preservation of Miocene pollen: plasmolysis captured in salt?

    Energy Technology Data Exchange (ETDEWEB)

    Durska, W.

    2016-07-01

    Exceptionally well-preserved Miocene pollen from the Bochnia salt mine of southern Poland is reported herein. The halite deposits within the salt mine belonging to Late Badenian (Miocene) marine evaporites originated in the Paratethys. Rounded and angular structures are present inside pollen grains. On the basis of the similarity with plasmolyzed pollen grains of modern plants, these structures are considered to represent cytoplasms plasmolyzed in the condensed brine prior to fossilization. Two forms of plasmolyzed cytoplasms (concave and convex) can be observed in modern pollen. Both are distinguished in the investigated fossil material. In porate and colporate grains the shape of the plasmolyzed cellular content is concave while in inaperturate it is convex. The plasmolysis form depends on the type of apertures and pollen shape. The percentage of pollen with fossilized cytoplasms within individual taxa is a valuable environmental indicator, as it depends on the proximity of the pollen-producing plant assemblages to the depositional setting. (Author)

  17. Determining the Ages and Eruption Rates of the Columbia River Basalt Group Magnetozones

    Science.gov (United States)

    Jarboe, N. A.; Coe, R. S.; Renne, P. R.; Glen, J. M.

    2009-12-01

    The Columbia River Basalt Group (CRBG) eruptions have a well defined relative magnetostratigraphy but have not been definitively correlated to the geomagnetic polarity time scale. Fifteen 40Ar/39Ar ages from lavas erupted in the R0 through R1 magnetozones of the CRBG, in conjunction with the geomagnetic polarity time scales (GPTS) of Lourens et al. (2004) and Billups et al. (2004) based on sea-floor spreading rates and orbital tuning, identify the R0 as the C5Cr chron. Particularly important for correlation to GPTS are four ages from transitionally magnetized lavas from the R0-N0 transition (Steens Reversal) found at Steens Mountain, Catlow Peak and Poker Jim Ridge. These transitionally magnetized lavas, found in sections separated by ~100 km and definitively erupted during the same reversal based on the similarity of their transitional field paths, have a weighted mean age 16.58 ±± 0.19 Ma (±± stands for two sigma). At the top of the Catlow Peak section, a more precise age of 16.654 ±± 0.050 Ma of the normally magnetized Oregon Canyon Tuff places further constraints on the age of the Steens Reversal. Using Isoplot’s Bayesian statistical “Stacked Beds” function on four flows at Catlow Peak (including the mean age of the Steens Reversal) gives a best age of the Steens Reversal at that section of 16.73 +0.13/-0.08 Ma (95% confidence). A normally magnetized Imnaha Basalt age of 16.85 ±± 0.42 Ma, a normally magnetized basalt age from Pole Creek (16.45 ±± 0.22 Ma), and other ages correlate the N0 to the C5Cn.3n chron. Depending on the geomagnetic polarity time scale model, the eruption rate from N0 through R2 (0.34-0.42 Ma in the middle and the bulk of the CRBG emplacement) averaged 0.33-0.45 km3/a and peaked at a rate 1 ½ to 4 ½ times higher during R2. Billups, K., H. Palike, J. E. T. Channell, J. C. Zachos, and N. J. Shackleton, Astronomic Calibration of the Late Oligocene Through Early Miocene Geomagnetic Polarity Time Scale, Earth and Planetary

  18. Petrology of offshore basalts of Bombay harbour area, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.

    glass are conspicuous. The chemical data indicate that the basalts are tholeiitic. Secondary minerals encountered support the view that the basalts are spilitised. Basalts of this area show affinities to both continental and oceanic types especially...

  19. Fish vertebra from Miocene beds at Govce, Slovenia

    Directory of Open Access Journals (Sweden)

    Vasja Mikuž

    2014-07-01

    Full Text Available The article discusses a vertebra and a small shark tooth found in the Miocene Govce sandstone near Govce west of Laško in central Slovenia. The vertebra belongs to a shark of the superorder Galeomorphii but we could not determine it with greater precision. The small tooth was assigned to Carcharias cf. taurus Rafinesque, 1810. The nannofossils in the sample are scarce and did not allow dating at biozone precision.

  20. EARLY MIOCENE INSULAR VERTEBRATES FROM LAERRU (SARDINIA, ITALY): PRELIMINARY NOTE

    OpenAIRE

    DANIEL ZOBOLI; GIAN LUIGI PILLOLA

    2017-01-01

    A new vertebrate assemblage was discovered in an Early  Miocene lacustrine deposit near the village of Laerru (northern Sardinia, Italy). The assemblage is composed by mammals, reptiles and a bird. The mammals are represented by three ruminants (cf. Sardomeryx oschiriensis, Pecora indet. small size and Pecora indet. very small size) and one dormouse (Peridyromys aff. murinus) while reptiles are represented by turtles (Trionychidae?) and crocodiles (cf. Diplocynodon sp.). A bird bone fragment ...

  1. Rb-Sr geochronology of some Miocene West Australian lamproites

    International Nuclear Information System (INIS)

    Allsopp, H.L.; Scott Smith, B.H.; Danchin, R.V.

    1985-01-01

    Rb-Sr ages are presented for four lamproite intrusions (Mount North, Old Leopold Hill, Mount Rose and Seltrust Pipe 2) located in the west Kimberley region of West Australia. The data are in agreement with the early Miocene ages previously obtained for the lamproites of this area. The lamproites are characterized by high initial-Sr ratios, indicative of derivation from an enriched source. Localized and regional mantle heterogeneity is indicated by new and existing data

  2. Updated chronology for the Miocene hominoid radiation in Western Eurasia

    Science.gov (United States)

    Casanovas-Vilar, Isaac; Alba, David M.; Garcés, Miguel; Robles, Josep M.; Moyà-Solà, Salvador

    2011-01-01

    Extant apes (Primates: Hominoidea) are the relics of a group that was much more diverse in the past. They originated in Africa around the Oligocene/Miocene boundary, but by the beginning of the Middle Miocene they expanded their range into Eurasia, where they experienced a far-reaching evolutionary radiation. A Eurasian origin of the great ape and human clade (Hominidae) has been favored by several authors, but the assessment of this hypothesis has been hampered by the lack of accurate datings for many Western Eurasian hominoids. Here we provide an updated chronology that incorporates recently discovered Iberian taxa and further reevaluates the age of many previously known sites on the basis of local biostratigraphic scales and magnetostratigraphic data. Our results show that identifiable Eurasian kenyapithecins (Griphopithecus and Kenyapithecus) are much younger than previously thought (ca. 14 Ma instead of 16 Ma), which casts serious doubts on the attribution of the hominoid tooth from Engelswies (16.3–16.5 Ma) to cf. Griphopithecus. This evidence is further consistent with an alternative scenario, according to which the Eurasian pongines and African hominines might have independently evolved in their respective continents from similar kenyapithecin ancestors, resulting from an early Middle Miocene intercontinental range extension followed by vicariance. This hypothesis, which would imply an independent origin of orthogrady in pongines and hominines, deserves further testing by accurately inferring the phylogenetic position of European dryopithecins, which might be stem pongines rather than stem hominines. PMID:21436034

  3. Hydrogeology of the basalts in the Uruguayan NW

    International Nuclear Information System (INIS)

    Hausman, A.; Fernandez, A.

    1967-01-01

    This work is about the hydrogeological aspects in the NW Uruguayan basaltic area. The results of this research are the main geological, morphological and hydrogeological aspects of the area as well as the characteristics and the color of the basalt and sandstones

  4. Influence of basalt/groundwater interactions on radionuclide migration

    International Nuclear Information System (INIS)

    Vandegrift, G.F.

    1984-01-01

    The work presented here is a partial summary of the experimental results obtained in the Laboratory Analog Program. Two aspects of this effort are (1) the interaction between simulated basaltic groundwater and basalt fissures that were either freshly cleaved or laboratory altered by hydrothermal treatment with the simulated groundwater and (2) the effect of this interaction on radionuclide migration through these basalt fissures. The following conclusions of this study bear heavily on the predicted safety of a basalt repository: Sorption properties of freshly fissured basalt and naturally aged basalt are quite different for different chemical species. Analog experiments predict that aged basalt would be an effective retarder of cesium, but would be much less so for actinide elements. Distribution ratios measured from batch experiments with finely ground rock samples (presenting unaltered rock surfaces) are not a reliable means of predicting radionuclide migration in geological repositories. As the near-repository area is resaturated by groundwater, its ability to retard actinide migration will be degraded with time. Disturbing the natural flow of groundwater through the repository area by constructing and backfilling the repository will modify the composition of groundwater. This modified groundwater is likely to interact with and to modify naturally aged basalt surfaces downstream from the repository

  5. Constructibility issues associated with a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Turner, D.A.

    1981-01-01

    This report contains the text and slide reproductions of a speech on nuclear waste disposal in basalt. The presentation addresses the layout of repository access shafts and subsurface facilities resulting from the conceptual design of a nuclear repository in basalt. The constructibility issues that must be resolved prior to construction are described

  6. Use of basaltic waste as red ceramic raw material

    Directory of Open Access Journals (Sweden)

    T. M. Mendes

    Full Text Available Abstract Nowadays, environmental codes restrict the emission of particulate matters, which result in these residues being collected by plant filters. This basaltic waste came from construction aggregate plants located in the Metropolitan Region of Londrina (State of Paraná, Brazil. Initially, the basaltic waste was submitted to sieving (< 75 μm and the powder obtained was characterized in terms of density and particle size distribution. The plasticity of ceramic mass containing 0%, 10%, 20%, 30%, 40% and 50% of basaltic waste was measured by Atterberg method. The chemical composition of ceramic formulations containing 0% and 20% of basaltic waste was determined by X-ray fluorescence. The prismatic samples were molded by extrusion and fired at 850 °C. The specimens were also tested to determine density, water absorption, drying and firing shrinkages, flexural strength, and Young's modulus. Microstructure evaluation was conducted by scanning electron microscopy, X-ray diffraction, and mercury intrusion porosimetry. Basaltic powder has similar physical and chemical characteristics when compared to other raw materials, and contributes to ceramic processing by reducing drying and firing shrinkage. Mechanical performance of mixtures containing basaltic powder is equivalent to mixtures without waste. Microstructural aspects such as pore size distribution were modified by basaltic powder; albite phase related to basaltic powder was identified by X-ray diffraction.

  7. Subduction controls on Miocene back-arc lavas from Sierra de Huantraico and La Matancilla, Argentina and new 40Ar/39Ar dating from the Mendoza Region, Argentina

    DEFF Research Database (Denmark)

    Dyhr, Charlotte Thorup; Holm, Paul Martin; Llambias, Eduardo J.

    2013-01-01

    Back-arc volcanism in the western Argentinian provinces of Mendoza and Neuquén has been widespread from the Miocene to historic times. We present a detailed investigation of profiles through two of the major Miocene volcanic areas of the region, the neighboring Huantraico and LaMatancilla plateaus......, including new 40Ar/39Ar age results of major and trace elements as well as Nd, Sr and Pb isotopic data. Four million years of eruptions from 24.4 ± 0.3 Ma (2σ) of alkali olivine basalts with OIB-type incompatible trace element enrichments at La Matancilla (~36.50°S) provide evidence for the presence of back......-arc mantle devoid of subduction-related components. In contrast, the lower Huantraico lavas (~37.30°S) require an atypical back-arc mantle, almost devoid of arc-like components (e.g. low La/Ta = 15–18 and Ba/La = 12–18), but with a more depleted isotopic signature (e.g. 87Sr/86Sr, 0.7033–0.7037) than...

  8. Hydrothermal interactions of cesium and strontium phases from spent unreprocessed fuel with basalt phases and basalts

    International Nuclear Information System (INIS)

    Komarneni, S.; Scheetz, B.E.; McCarthy, G.J.; Coons, W.E.

    1980-03-01

    This investigation is a segment of an extensive research program aimed at investigating the feasibility of long-term, subsurface storage of commercial nuclear waste. Specifically, it is anticipated that the waste will be housed in a repository mined from the basalt formations which lie beneath the Hanford Site. The elements monitored during the present experiments were Cs and Sr. These two elements represent significant biohazards if released from a repository and are the major heat producing radionuclides present in commercial radioactive waste. Several Cs phases and/or solutions were reacted with either isolated basalt phases or bulk-rock basalt, and the resulting solids and solutions were analyzed. The hydrothermal reactivity of SrZrO 3 , which is believed to be a probable host for Sr in SFE was investigated. While so far no evidence exists which indicates that Sr is present in a water soluble phase in spent fuel elements (SFE), detailed investigation of a potential hazard is warranted. This investigation has determined that some Cs compounds likely to be stable components of spent fuel (i.e., CsOH, Cs 2 MoO 4 , Cs 2 U 2 O 7 ) have significant hydrothermal solubilities. These solubilities are greatly decreased in the presence of basalt and/or basalt minerals. The decrease in the amount of Cs in solution results from reactions which form pollucite and/or CsAlSiO 4 , with the production of pollucite exceeding that of CsAlSiO 4 . Dissolution of β-Cs 2 U 2 O 7 implies solubilizing a uranium species to an undetermined extent. The production of schoepite (UO 3 .3H 2 O) during some experiments containing basalt phases, indicates a tendency to oxidize U 4+ to U 6+ . When diopside (nominally CaMgSi 2 O 6 ) and β-Cs 2 U 2 O 7 were hydrothermally reacted, at 300 0 C both UO 2 and UO 3 .3H 2 O were produced. Experiments on SrZrO 3 show it to be an unreactive phase

  9. Hydrothermal interactions of cesium and strontium phases from spent unreprocessed fuel with basalt phases and basalts

    Energy Technology Data Exchange (ETDEWEB)

    Komarneni, S.; Scheetz, B.E.; McCarthy, G.J.; Coons, W.E.

    1980-03-01

    This investigation is a segment of an extensive research program aimed at investigating the feasibility of long-term, subsurface storage of commercial nuclear waste. Specifically, it is anticipated that the waste will be housed in a repository mined from the basalt formations which lie beneath the Hanford Site. The elements monitored during the present experiments were Cs and Sr. These two elements represent significant biohazards if released from a repository and are the major heat producing radionuclides present in commercial radioactive waste. Several Cs phases and/or solutions were reacted with either isolated basalt phases or bulk-rock basalt, and the resulting solids and solutions were analyzed. The hydrothermal reactivity of SrZrO/sub 3/, which is believed to be a probable host for Sr in SFE was investigated. While so far no evidence exists which indicates that Sr is present in a water soluble phase in spent fuel elements (SFE), detailed investigation of a potential hazard is warranted. This investigation has determined that some Cs compounds likely to be stable components of spent fuel (i.e., CsOH, Cs/sub 2/MoO/sub 4/, Cs/sub 2/U/sub 2/O/sub 7/) have significant hydrothermal solubilities. These solubilities are greatly decreased in the presence of basalt and/or basalt minerals. The decrease in the amount of Cs in solution results from reactions which form pollucite and/or CsAlSiO/sub 4/, with the production of pollucite exceeding that of CsAlSiO/sub 4/. Dissolution of ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ implies solubilizing a uranium species to an undetermined extent. The production of schoepite (UO/sub 3/.3H/sub 2/O) during some experiments containing basalt phases, indicates a tendency to oxidize U/sup 4 +/ to U/sup 6 +/. When diopside (nominally CaMgSi/sub 2/O/sub 6/) and ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ were hydrothermally reacted, at 300/sup 0/C both UO/sub 2/ and UO/sub 3/.3H/sub 2/O were produced. Results of experiments on SrZrO/sub 3/ show it to be

  10. [Determination of Total Iron and Fe2+ in Basalt].

    Science.gov (United States)

    Liu, Jian-xun; Chen, Mei-rong; Jian, Zheng-guo; Wu, Gang; Wu, Zhi-shen

    2015-08-01

    Basalt is the raw material of basalt fiber. The content of FeO and Fe2O3 has a great impact on the properties of basalt fibers. ICP-OES and dichromate method were used to test total Fe and Fe(2+) in basalt. Suitable instrument parameters and analysis lines of Fe were chosen for ICP-OES. The relative standard deviation (RSD) of ICP-OES is 2.2%, and the recovery is in the range of 98%~101%. The method shows simple, rapid and highly accurate for determination of total Fe and Fe(2+) in basalt. The RSD of ICP-OES and dichromate method is 0.42% and 1.4%, respectively.

  11. Petrological constraints on the high-Mg basalts from Capo Marargiu (Sardinia, Italy): Evidence of cryptic amphibole fractionation in polybaric environments

    Science.gov (United States)

    Tecchiato, Vanni; Gaeta, Mario; Mollo, Silvio; Scarlato, Piergiorgio; Bachmann, Olivier; Perinelli, Cristina

    2018-01-01

    This study deals with the textural and compositional characteristics of the calc-alkaline stratigraphic sequence from Capo Marargiu Volcanic District (CMVD; Sardinia island, Italy). The area is dominated by basaltic to intermediate hypabyssal (dikes and sills) and volcanic rocks (lava flows and pyroclastic deposits) emplaced during the Oligo-Miocene orogenic magmatism of Sardinia. Interestingly, a basaltic andesitic dome hosts dark-grey, crystal-rich enclaves containing up 50% of millimetre- to centimetre-sized clinopyroxene and amphibole crystals. This mineral assemblage is in equilibrium with a high-Mg basalt recognised as the parental magma of the entire stratigraphic succession at CMVD. Analogously, centimetre-sized clots of medium- and coarse-grained amphibole + plagioclase crystals are entrapped in andesitic dikes that ultimately intrude the stratigraphic sequence. Amphibole-plagioclase cosaturation occurs at equilibrium with a differentiated basaltic andesite. Major and trace element modelling indicates that the evolutionary path of magma is controlled by a two-step process driven by early olivine + clinopyroxene and late amphibole + plagioclase fractionation. In this context, enclaves represent parts of a cumulate horizon segregated at the early stage of differentiation of the precursory high-Mg basalt. This is denoted by i) resorption effects and sharp transitions between Mg-rich and Mg-poor clinopyroxenes, indicative of pervasive dissolution phenomena followed by crystal re-equilibration and overgrowth, and ii) reaction minerals found in amphibole coronas formed at the interface with more differentiated melts infiltrating within the cumulate horizon, and carrying the crystal-rich material with them upon eruption. Coherently, the mineral chemistry and phase relations of enclaves indicate crystallisation in a high-temperature, high-pressure environment under water-rich conditions. On the other hand, the upward migration and subsequent fractionation of the

  12. Basalt alteration and basalt-waste interaction in the Pasco Basin of Washington State. Final report

    International Nuclear Information System (INIS)

    Benson, L.V.; Carnahan, C.L.; Apps, J.A.; Mouton, C.A.; Corrigan, D.J.; Frisch, C.J.; Shomura, L.K.

    1978-09-01

    A study was conducted to determine the nature of the minerals which coat vesicle and fracture surfaces in the Grande Ronde Basalt Formation, simulate the mass transfer which led to their precipitation, and predict the mass transfer associated with the dissolution of spent unreprocessed fuel (SURF). Scanning electron microscopy (SEM), petrographic, x-ray diffraction (XRD), and electron microprobe (EMP) analyses have been made on a series of samples taken from 1100 ft (335.3 m) of core from core hole DC2. Preliminary simulations of the mass transfer associated with basalt dissolution in a thermodynamically closed system have been accomplished. In addition two mass transfer codes have been modified to facilitate data base changes. Thermochemical data for uranium and plutonium have been collected and converted to standard state conditions. These data will be critically evaluated and input to the mass transfer data base in the near future

  13. Strontium stable isotope behaviour accompanying basalt weathering

    Science.gov (United States)

    Burton, K. W.; Parkinson, I. J.; Gíslason, S. G. R.

    2016-12-01

    The strontium (Sr) stable isotope composition of rivers is strongly controlled by the balance of carbonate to silicate weathering (Krabbenhöft et al. 2010; Pearce et al. 2015). However, rivers draining silicate catchments possess distinctly heavier Sr stable isotope values than their bedrock compositions, pointing to significant fractionation during weathering. Some have argued for preferential release of heavy Sr from primary phases during chemical weathering, others for the formation of secondary weathering minerals that incorporate light isotopes. This study presents high-precision double-spike Sr stable isotope data for soils, rivers, ground waters and estuarine waters from Iceland, reflecting both natural weathering and societal impacts on those environments. The bedrock in Iceland is dominantly basaltic, d88/86Sr ≈ +0.27, extending to lighter values for rhyolites. Geothermal waters range from basaltic Sr stable compositions to those akin to seawater. Soil pore waters reflect a balance of input from primary mineral weathering, precipitation and litter recycling and removal into secondary phases and vegetation. Rivers and ground waters possess a wide range of d88/86Sr compositions from +0.101 to +0.858. Elemental and isotope data indicate that this fractionation primarily results from the formation or dissolution of secondary zeolite (d88/86Sr ≈ +0.10), but also carbonate (d88/86Sr ≈ +0.22) and sometimes anhydrite (d88/86Sr ≈ -0.73), driving the residual waters to heavier or lighter values, respectively. Estuarine waters largely reflect mixing with seawater, but are also be affected by adsorption onto particulates, again driving water to heavy values. Overall, these data indicate that the stability and nature of secondary weathering phases, exerts a strong control on the Sr stable isotope composition of silicate rivers. [1] Krabbenhöft et al. (2010) Geochim. Cosmochim. Acta 74, 4097-4109. [2] Pearce et al. (2015) Geochim. Cosmochim. Acta 157, 125-146.

  14. BASALT A: Basaltic Terrains in Idaho and Hawaii as Planetary Analogs for Mars Geology and Astrobiology

    Science.gov (United States)

    Hughes, Scott S.; Haberle, Christopher W.; Nawotniak, Shannon E. Kobs; Sehlke, Alexander; Garry, W. Brent; Elphic, Richard C.; Payler, Sam J.; Stevens, Adam H.; Cockell, Charles S.; Brady, Allyson L.; hide

    2018-01-01

    Assessments of field research target regions are described within two notably basaltic geologic provinces as Earth analogs to Mars. Regions within the eastern Snake River Plain of Idaho and the Big Island of Hawaii, USA, provinces that represent analogs of present-day and early Mars, respectively, were evaluated on the basis of geologic settings, rock lithology and geochemistry, rock alteration, and climate. Each of these factors provide rationale for the selection of specific targets for field research in five analog target regions: (1) Big Craters and (2) Highway lava flows at Craters of the Moon National Monument and Preserve, Idaho; and (3) Mauna Ulu low shield, (4) Kilauea Iki lava lake and (5) Kilauea caldera in the Kilauea Volcano summit region and the East Rift Zone of Hawaii. Our evaluation of compositional and textural differences, as well as the effects of syn- and post-eruptive rock alteration, shows that the basaltic terrains in Idaho and Hawaii provide a way to characterize the geology and major geologic substrates that host biological activity of relevance to Mars exploration. This work provides the foundation to better understand the scientific questions related to the habitability of basaltic terrains, the rationale behind selecting analog field targets, and their applicability as analogs to Mars.

  15. Thermobarometry for spinel lherzolite xenoliths in alkali basalts

    Science.gov (United States)

    Ozawa, Kazuhito; Youbi, Nasrrddine; Boumehdi, Moulay Ahmed; Nagahara, Hiroko

    2016-04-01

    geothermobarometry based on reactions with large and distinct volume changes, is necessary. Specification of mineral domains and their components representing the thermal state of the mantle just before xenolith extraction is one of the major tasks for the establishment of reliable geothermobarometry for spinel lherzolite xenoliths. Systematic variations of such mineralogical information among xenoliths transported by a single volcanic eruption guarantees proper estimation of a mantle geotherm. For the development of such geobarometry, it is important to choose appropriate xenolith locality, where previous studies provide enough information and where many xenolith samples are available for extending a range of derivation depth. Spinel lherzolite xenoliths in alkali basalts from Bou Ibalhatene maars in the Middle Atlas in Morocco are suitable study target. Geochemical, geochronological, petrological, and rheological aspects of the spinel lherzolite xenoliths have been studied (Raffone et al. 2009; El Messbahi et al., 2015; Witting et al., 2010; El Azzouzi et al., 2010), which show that they represent fragments of the lithospheric mantle formed and modified since 1.7Ga before their extraction from Miocene to recent. We have pinpointed portions of minerals in the xenolith samples and their components representing condition just before their entrapment in magmas, on which appropriate geothermobarometers are applied and detected ~0.5GPa pressure difference (1.5-2.0GPa) for ~100°C variation in temperatures (950-1050°C).

  16. Miocene vegetation shift and climate change: Evidence from the Siwalik of Nepal

    Science.gov (United States)

    Srivastava, Gaurav; Paudayal, Khum N.; Utescher, Torsten; Mehrotra, R. C.

    2018-02-01

    We reconstruct climate and vegetation applying the Coexistence Approach (CA) methodology on two palaeofloras recovered from the Lower (middle Miocene; 13-11 Ma) and Middle Siwalik (late Miocene; 9.5-6.8 Ma) sediments of Surai Khola section, Nepal. The reconstructed mean annual temperature (MAT) and cold month mean temperature (CMT) show an increasing trend, while warm month mean temperature (WMT) remains nearly the same during the period. The reconstructed precipitation data indicates that the summer monsoon precipitation was nearly the same during the middle and late Miocene, while the winter season precipitation significantly decreased in the late Miocene. The overall precipitation infers increased rainfall seasonality during the late Miocene. The vegetation during the middle Miocene was dominated by wet evergreen taxa, whereas deciduous ones increased significantly during the late Miocene. The reconstructed climate data indicates that high temperature and significantly low precipitation during the winter season (dry season) in the late Miocene might have enhanced forest fire which favoured the expansion of C4 plants over C3 plants during the period. This idea gets further support not only from a recent forest fire in northern India that was caused by the weakening of winter precipitation, but also from the burnt wood recovered from the late Miocene Siwalik sediments of northern India.

  17. The Thickness and Volume of Young Basalts Within Mare Imbrium

    Science.gov (United States)

    Chen, Yuan; Li, Chunlai; Ren, Xin; Liu, Jianjun; Wu, Yunzhao; Lu, Yu; Cai, Wei; Zhang, Xunyu

    2018-02-01

    Basaltic volcanism is one of the most important geologic processes of the Moon. Research on the thickness and volume of late-stage basalts of Mare Imbrium helps better understand the source of lunar volcanism and eruption styles. Based on whether apparent flow fronts exist or not, the late-stage basalts within Mare Imbrium were divided into two groups, namely, Upper Eratosthenian basalts (UEm) and Lower Eratosthenian basalts (LEm). Employing the topographic profile analysis method for UEm and the crater excavation technique for LEm, we studied the thickness and distribution of Eratosthenian basalts in Mare Imbrium. For the UEm units, their thicknesses were estimated to be 16-34 (±2) m with several layers of individual lava ( 8-13 m) inside. The estimated thickness of LEm units was 14-45(±1) m, with a trend of reducing thickness from north to south. The measured thickness of late-stage basalts around the Chang'E-3 landing site ( 37 ± 1 m) was quite close to the results acquired by the lunar penetrating radar carried on board the Yutu Rover ( 35 m). The total volume of the late-stage basalts in Mare Imbrium was calculated to be 8,671 (±320) km3, which is 4 times lower than that of Schaber's estimation ( 4 × 104 km3). Our results indicate that the actual volume is much lower than previous estimates of the final stage of the late basaltic eruption of Mare Imbrium. Together, the area flux and transport distance of the lava flows gradually decreased with time. These results suggest that late-stage volcanic evolution of the Moon might be revised.

  18. Simulating the structure of gypsum composites using pulverized basalt waste

    Directory of Open Access Journals (Sweden)

    Buryanov Аleksandr

    2017-01-01

    Full Text Available This paper examines the possibility of simulating the structure of gypsum composite modified with basalt dust waste to make materials and products based on it. Structural simulating of the topological space in gypsum modified composite by optimizing its grain-size composition highly improves its physical and mechanical properties. Strength and density tests have confirmed the results of the simulation. The properties of modified gypsum materials are improved by obtaining of denser particle packing in the presence of hemihydrate of finely dispersed basalt and plasticizer particles in the system, and by engaging basalt waste in the structuring process of modified gypsum stone.

  19. Basaltic volcanic episodes of the Yucca Mountain region

    International Nuclear Information System (INIS)

    Crowe, B.M.

    1990-01-01

    The purpose of this paper is to summarize briefly the distribution and geologic characteristics of basaltic volcanism in the Yucca Mountain region during the last 10--12 Ma. This interval largely postdates the major period of silicic volcanism and coincides with and postdates the timing of major extensional faulting in the region. Field and geochronologic data for the basaltic rocks define two distinct episodes. The patterns in the volume and spatial distribution of these basaltic volcanic episodes in the central and southern part of the SNVF are used as a basis for forecasting potential future volcanic activity in vicinity of Yucca Mountain. 33 refs., 2 figs

  20. Discover Floods Educators Guide

    Science.gov (United States)

    Project WET Foundation, 2009

    2009-01-01

    Now available as a Download! This valuable resource helps educators teach students about both the risks and benefits of flooding through a series of engaging, hands-on activities. Acknowledging the different roles that floods play in both natural and urban communities, the book helps young people gain a global understanding of this common--and…

  1. Middle Miocene carnivorans from the Monarch Mill Formation, Nevada

    Directory of Open Access Journals (Sweden)

    Kent Smith

    2016-02-01

    Full Text Available he lowest part of the Monarch Mill Formation in the Middlegate basin, west-central Nevada, has yielded a middle Miocene (Barstovian Land Mammal Age vertebrate assemblage, the Eastgate local fauna. Paleobotanical evidence from nearby, nearly contemporaneous fossil leaf assemblages indicates that the Middle Miocene vegetation in the area was mixed coniferous and hardwood forest and chaparral-sclerophyllous shrubland, and suggests that the area had been uplifted to 2700–2800 m paleoaltitude before dropping later to near its present elevation of 1600 m. Thus, the local fauna provides a rare glimpse at a medium- to high-altitude vertebrate community in the intermountain western interior of North America. The local fauna includes the remains of fish, amphibians, reptiles, birds, and 25 families of mammals. Carnivorans, the focus of this study, include six taxa (three of which are new belonging to four families. Canidae are represented by the borophagine Tomarctus brevirostris and the canine Leptocyon sp. indet. The earliest record and second North American occurrence of the simocyonine ailurid Actiocyon is represented by A. parverratis sp. nov. Two new mustelids, Brevimalictis chikasha gen. et sp. nov. and Negodiaetictis rugatrulleum gen. et sp. nov., may represent Galictinae but are of uncertain subfamilial and tribal affinity. The fourth family is represented by the felid Pseudaelurus sp. indet. Tomarctus brevirostris is limited biochronologically to the Barstovian land mammal age and thus is consistent with the age indicated by other members of the Eastgate local fauna as well as by indirect tephrochronological dates previously associated with the Monarch Mill Formation. Actiocyon parverratis sp. nov. extends the temporal range of the genus Actiocyon from late Clarendonian back to the Barstovian. The Eastgate local fauna improves our understanding of mammalian successions and evolution, during and subsequent to the Mid-Miocene Climatic Optimum

  2. Enhanced methane emission during carbonaceous sediment-basalt interactions as a mechanism for mass extinction

    Science.gov (United States)

    Kubo, A. I.; Day, J. M.; Ryabov, V. V.; Taylor, L. A.

    2016-12-01

    volatiles necessary to cause a runaway greenhouse effect and the estimated emission of flood basalts.

  3. Natural product terpenoids in Eocene and Miocene conifer fossils.

    Science.gov (United States)

    Otto, Angelika; White, James D; Simoneit, Bernd R T

    2002-08-30

    Numerous saturated and aromatic hydrocarbons, but not polar compounds, originating from plants and microorganisms (biomarkers) have been reported in sediments, coals, and petroleum. Here we describe natural product terpenoids found in two fossil conifers, Taxodium balticum (Eocene) and Glyptostrobus oregonensis (Miocene). A similar terpenoid pattern is also observed in extant Taxodium distichum. The preservation of characteristic terpenoids (unaltered natural products) in the fossil conifers supports their systematic assignment to the Cypress family (Cupressaceae sensu lato). The results also show that fossil conifers can contain polar terpenoids, which are valuable markers for (paleo)chemosystematics and phylogeny.

  4. Miocene shale tectonics in the Moroccan margin (Alboran Sea)

    Science.gov (United States)

    Do Couto, D.; El Abbassi, M.; Ammar, A.; Gorini, C.; Estrada, F.; Letouzey, J.; Smit, J.; Jolivet, L.; Jabour, H.

    2011-12-01

    The Betic (Southern Spain) and Rif (Morocco) mountains form an arcuate belt that represents the westernmost termination of the peri-mediterranean Alpine mountain chain. The Miocene Alboran Basin and its subbasins is located in the hinterland of the Betic-Rif belt. It is considered to be a back-arc basin that developed during the coeval westward motion of the Alboran domain and the extensional collapse of previously thickened crust of the Betic-Rif belt. The Western Alboran Basin (WAB) is the major sedimentary depocenter with a sediment thickness in excess of 10 km, it is bordered by the Gibraltar arc, the volcanic Djibouti mounts and the Alboran ridge. Part of the WAB is affected by shale tectonics and associated mud volcanism. High-quality 2D seismic profiles acquired on the Moroccan margin of the Alboran Basin during the last decade reveal the multiple history of the basin. This study deals with the analysis of a number of these seismic profiles that are located along and orthogonal to the Moroccan margin. Seismic stratigraphy is calibrated from industrial wells. We focus on the interactions between the gravity-driven tectonic processes and the sedimentation in the basin. Our seismic interpretation confirms that the formation of the WAB began in the Early Miocene (Aquitanian - Burdigalian). The fast subsidence of the basin floor coeval to massive sedimentation induced the undercompaction of early miocene shales during their deposition. Downslope migration of these fine-grained sediments initiated during the deposition of the Langhian siliciclastics. This gravity-driven system was accompanied by continuous basement subsidence and induced disharmonic deformation in Mid Miocene units (i.e. not related to basement deformation). The development of shale-cored anticlines and thrusts in the deep basin is the result of compressive deformation at the front of the gravity-driven system and lasted for ca. 15 Ma. The compressive front has been re-activated by strong

  5. Shark-bitten vertebrate coprolites from the Miocene of Maryland

    Science.gov (United States)

    Godfrey, Stephen J.; Smith, Joshua B.

    2010-05-01

    Coprolites (fossilized feces) preserve a wide range of biogenic components, from bacteria and spores to a variety of vertebrate tissues. Two coprolites from the Calvert Cliffs outcrop belt (Miocene-aged Chesapeake Group), MD, USA, preserve shark tooth impressions in the form of partial dental arcades. The specimens are the first known coprolites to preserve vertebrate tooth marks. They provide another example of trace fossils providing evidence of prehistoric animal behaviors that cannot be directly approached through the study of body fossils. Shark behaviors that could account for these impressions include: (1) aborted coprophagy, (2) benthic or nektonic exploration, or (3) predation.

  6. An Early Miocene bumble bee from northern Bohemia (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    Jakub Prokop

    2017-10-01

    Full Text Available A new species of fossil bumble bee (Apinae: Bombini is described and figured from Early Miocene (Burdigalian deposits of the Most Basin at the Bílina Mine, Czech Republic. Bombus trophonius sp. n., is placed within the subgenus Cullumanobombus Vogt and distinguished from the several species groups therein. The species is apparently most similar to the Nearctic B. (Cullumanobombus rufocinctus Cresson, the earliest-diverging species within the clade and the two may be related only by symplesiomorphies. The age of the fossil is in rough accordance with divergence estimations for Cullumanobombus.

  7. Flood action plans

    International Nuclear Information System (INIS)

    Slopek, R.J.

    1995-01-01

    Safe operating procedures developed by TransAlta Utilities for dealing with flooding, resulting from upstream dam failures or extreme rainfalls, were presented. Several operating curves developed by Monenco AGRA were described, among them the No Overtopping Curve (NOC), the Safe Filling Curve (SFC), the No Spill Curve (NSC) and the Guaranteed Fill Curve (GFC). The concept of an operational comfort zone was developed and defined. A flood action plan for all operating staff was created as a guide in case of a flooding incident. Staging of a flood action plan workshop was described. Dam break scenarios pertinent to the Bow River were developed for subsequent incorporation into a Flood Action Plan Manual. Evaluation of the technical presentations made during workshops were found them to have been effective in providing operating staff with a better understanding of the procedures that they would perform in an emergency. 8 figs

  8. Melt rock components in KREEPy breccia 15205: Petrography and mineral chemistry of KREEP basalts and quartz-normative mare basalts

    Science.gov (United States)

    Shervais, John W.; Vetter, Scott K.

    1993-05-01

    Many current models for the origin of lunar highland rocks feature as an essential component the assimilation of KREEPy material by primitive magmas parental to the Mg-rich suite and alkali suite plutonic rocks. Similar models have also been proposed for the origin of various mare basalt suites. However, any model which considers assimilation of KREEP an important petrologic process must sooner-or-later deal with the question: what is KREEP? Because pristine KREEP basalts are rare, and most known samples are small (e.g., 15382/15386), the geochemical variability of KREEP basalts is poorly known. Other KREEP compositions which are commonly used in these models include the hypothetical 'high-K KREEP' component of Warren and Wasson, which is derived from Apollo 14 soil data, and the 'superKREEP' quartz-monzodiorite 15405. Lunar breccia 15205 is a polymict regolith breccia that consists of approximately 20% KREEP basalt clasts and 20% quartz-normative basalt clasts in a KREEP-rich matrix. Bulk rock mixing calculations show that this sample comprises about 84% KREEP. The clasts range up to 1 cm in size, but most are considerably smaller. The primary aim is to characterize pristine KREEP basalts petrographically, to establish the range in chemical compositions of KREEP basalts, and to test models that were proposed for their origin. In addition, we may be able to extend the compositional range recognized in the quartz-normative basalt suite and cast some light on its origin as well. Preliminary whole rock geochemical data on the KREEP basalts are presented in a companion paper by M.M. Lindstrom and co-workers. Concentration is on petrography and mineral chemistry of these clasts, and the implications these data have for the origin of the different melt rock suites.

  9. Paleomagnetism of late Archaean flood basalt terrains : implications for early Earth geodynamics and geomagnetism

    NARCIS (Netherlands)

    Strik, G.H.M.A.

    2004-01-01

    Palaeomagnetic studies are e.g. important for demonstrating and quantifying horizontal movement and rotation of pieces of the Earth's crust. The constant movement and recycling of plates, in other words plate tectonics, is an important mechanism for the Earth to lose its heat. It is generally

  10. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  11. Engineered barrier development for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    The BWIP Engineered Barrier Program has been developed to provide an integrated approach to the development of site-specific Engineered Barrier assemblages for a repository located in basalt. The goal of this program is to specify engineered and natural barriers which will ensure that nuclear and non-radioactive hazardous materials emplaced in a repository in basalt do not exceed acceptable rates of release to the biosphere. A wide range of analytical and experimental activities related to the basalt repository environment, waste package environment, waste/barrier/rock interactions, and barrier performance assessment provide the basis for selection of systems capable of meeting licensing requirements. Work has concentrated on specifying and testing natural and man-made materials which can be used to plug boreholes in basalt and which can be used as multiple barriers to surround nuclear waste forms and containers. The Engineered Barriers Program is divided into two major activities: multiple barrier studies and borehole plugging. 8 figures, 4 tables

  12. Geochemical characterization of oceanic basalts using artificial neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.

    method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). Artificial Neural Network (ANN) technique as a supervised Learning Vector Quantisation (LVQ) is applied to identify the inherent...

  13. Alteration of basaltic glasses from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    Textural, mineralogical and compositional characteristics of basaltic glasses from the Central Indian Ocean show them to be altered to varying extents through their interaction with the seawater, resulting in the formation of palagonite. The major...

  14. A note on incipient spilitisation of central Indian basin basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Iyer, S.D.

    Rocks dredged in the vicinity of the 79 degrees E fracture zone, in the Central Indian Basin, are sub-alkaline basalts, which are regarded as precursors to spilites. The minerals identified are mainly albitic plagioclase, augite, olivine, and less...

  15. [Comparative carcinogenic properties of basalt fiber and chrysotile-asbestos].

    Science.gov (United States)

    Nikitina, O V; Kogan, F M; Vanchugova, N N; Frash, V N

    1989-01-01

    In order to eliminate asbestos adverse effect on workers' health it was necessary to use mineral rayon, primarily basalt fibre, instead of asbestos. During a chronic experiment on animals the oncogenicity of 2 kinds of basalt fibre was studied compared to chrysotile asbestos. The dust dose of 25 mg was twice administered by intraperitonial route. All types of dust induced the onset of intraperitonial mesotheliomas but neoplasm rates were significantly lower in the groups exposed to basalt fibre. There was no credible data on the differences between the groups exposed to various types of basalt fibre. Since the latter produced some oncogenic effect, it was necessary to develop a complex of antidust measures, fully corresponding to the measures adopted for carcinogenic dusts.

  16. Trace Element Abundances in Eucrite Basalts: Enrichment or Depletion?

    Science.gov (United States)

    Castle, N. R.

    2018-05-01

    It is not clear how incompatible trace element (ITE) variation in eucrite basalts originated. Here, mechanisms for relative ITE enrichment or depletion are experimentally evaluated in an attempt to reconcile the Stannern and main group eucrites.

  17. Iowa Flood Information System

    Science.gov (United States)

    Demir, I.; Krajewski, W. F.; Goska, R.; Mantilla, R.; Weber, L. J.; Young, N.

    2011-12-01

    The Iowa Flood Information System (IFIS) is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to flood inundation maps, real-time flood conditions, flood forecasts both short-term and seasonal, flood-related data, information and interactive visualizations for communities in Iowa. The key element of the system's architecture is the notion of community. Locations of the communities, those near streams and rivers, define basin boundaries. The IFIS provides community-centric watershed and river characteristics, weather (rainfall) conditions, and streamflow data and visualization tools. Interactive interfaces allow access to inundation maps for different stage and return period values, and flooding scenarios with contributions from multiple rivers. Real-time and historical data of water levels, gauge heights, and rainfall conditions are available in the IFIS by streaming data from automated IFC bridge sensors, USGS stream gauges, NEXRAD radars, and NWS forecasts. Simple 2D and 3D interactive visualizations in the IFIS make the data more understandable to general public. Users are able to filter data sources for their communities and selected rivers. The data and information on IFIS is also accessible through web services and mobile applications. The IFIS is optimized for various browsers and screen sizes to provide access through multiple platforms including tablets and mobile devices. The IFIS includes a rainfall-runoff forecast model to provide a five-day flood risk estimate for around 500 communities in Iowa. Multiple view modes in the IFIS accommodate different user types from general public to researchers and decision makers by providing different level of tools and details. River view mode allows users to visualize data from multiple IFC bridge sensors and USGS stream gauges to follow flooding condition along a river. The IFIS will help communities make better-informed decisions on the occurrence of floods, and will alert communities

  18. Chemical magnetization when determining Thellier paleointensity experiments in oceanic basalts

    Science.gov (United States)

    Tselebrovskiy, Alexey; Maksimochkin, Valery

    2017-04-01

    The natural remanent magnetization (NRM) of oceanic basalts selected in the rift zones of the Mid-Atlantic Ridge (MAR) and the Red Sea has been explored. Laboratory simulation shows that the thermoremanent magnetization and chemical remanent magnetization (CRM) in oceanic basalts may be separated by using Tellier-Coe experiment. It was found that the rate of CRM destruction is about four times lower than the rate of the partial thermoremanent magnetization formation in Thellier cycles. The blocking temperatures spectrum of chemical component shifted toward higher temperatures in comparison with the spectrum of primary thermoremanent magnetization. It was revealed that the contribution of the chemical components in the NRM increases with the age of oceanic basalts determined with the analysis of the anomalous geomagnetic field (AGF) and spreading theory. CRM is less than 10% at the basalts aged 0.2 million years, less than 50% at basalts aged 0.35 million years, from 60 to 80% at basalts aged 1 million years [1]. Geomagnetic field paleointensity (Hpl) has been determined through the remanent magnetization of basalt samples of different ages related to Brunhes, Matuyama and Gauss periods of the geomagnetic field polarity. The value of the Hpl determined by basalts of the southern segment of MAR is ranged from 17.5 to 42.5 A/m, by the Reykjanes Ridge basalts — from 20.3 to 44 A/m, by the Bouvet Ridge basalts — from 21.7 to 34.1 A/m. VADM values calculated from these data are in good agreement with the international paleointensity database [2] and PISO-1500 model [3]. Literature 1. Maksimochkin V., Tselebrovskiy A., (2015) The influence of the chemical magnetization of oceanic basalts on determining the geomagnetic field paleointensity by the thellier method, moscow university physics bulletin, 70(6):566-576, 2. Perrin, M., E. Schnepp, and V. Shcherbakov (1998), Update of the paleointensity database, Eos Trans. AGU, 79, 198. 3. Channell JET, Xuan C, Hodell DA (2009

  19. Diversity of life in ocean floor basalt

    Science.gov (United States)

    Thorseth, I. H.; Torsvik, T.; Torsvik, V.; Daae, F. L.; Pedersen, R. B.

    2001-12-01

    Electron microscopy and biomolecular methods have been used to describe and identify microbial communities inhabiting the glassy margins of ocean floor basalts. The investigated samples were collected from a neovolcanic ridge and from older, sediment-covered lava flows in the rift valley of the Knipovich Ridge at a water depth around 3500 m and an ambient seawater temperature of -0.7°C. Successive stages from incipient microbial colonisation, to well-developed biofilms occur on fracture surfaces in the glassy margins. Observed microbial morphologies are various filamentous, coccoidal, oval, rod-shaped and stalked forms. Etch marks in the fresh glass, with form and size resembling the attached microbes, are common. Precipitation of alteration products around microbes has developed hollow subspherical and filamentous structures. These precipitates are often enriched in Fe and Mn. The presence of branching and twisted stalks that resemble those of the iron-oxidising Gallionella, indicate that reduced iron may be utilised in an energy metabolic process. Analysis of 16S-rRNA gene sequences from microbes present in the rock samples, show that the bacterial population inhabiting these samples cluster within the γ- and ɛ-Proteobacteria and the Cytophaga/Flexibacter/Bacteroides subdivision of the Bacteria, while the Archaea all belong to the Crenarchaeota kingdom. This microbial population appears to be characteristic for the rock and their closest relatives have previously been reported from cold marine waters in the Arctic and Antarctic, deep-sea sediments and hydrothermal environments.

  20. Magnesium-rich Basalts on Mercury

    Science.gov (United States)

    Martel, L. M. V.

    2013-05-01

    X-ray and gamma-ray spectrometers on NASA's MESSENGER spacecraft are making key measurements regarding the composition and properties of the surface of Mercury, allowing researchers to more clearly decipher the planet's formation and geologic history. The origin of the igneous rocks in the crust of Mercury is the focus of recent research by Karen Stockstill-Cahill and Tim McCoy (National Museum of Natural History, Smithsonian Institution), along with Larry Nittler and Shoshana Weider (Carnegie Institution of Washington) and Steven Hauck II (Case Western Reserve University). Using the well-known MELTS computer code Stockstill-Cahill and coauthors worked with MESSENGER-derived and rock-analog compositions to constrain petrologic models of the lavas that erupted on the surface of Mercury. Rock analogs included a partial melt of the Indarch meteorite and a range of Mg-rich terrestrial rocks. Their work shows the lavas on Mercury are most similar to terrestrial magnesian basalt (with lowered FeO content). The implications of the modeling are that Mg-rich lavas came from high-temperature sources in Mercury's mantle and erupted at high temperature with exceptionally low viscosity into thinly bedded and laterally extensive flows, concepts open to further evaluation by laboratory experiments and by geologic mapping of Mercury's surface using MESSENGER's imaging system and laser altimeter to document flow features and dimensions.

  1. Basalt FRP Spike Repairing of Wood Beams

    Directory of Open Access Journals (Sweden)

    Luca Righetti

    2015-08-01

    Full Text Available This article describes aspects within an experimental program aimed at improving the structural performance of cracked solid fir-wood beams repaired with Basalt Fiber Reinforced Polymer (BFRP spikes. Fir wood is characterized by its low density, low compression strength, and high level of defects, and it is likely to distort when dried and tends to fail under tension due to the presence of cracks, knots, or grain deviation. The proposed repair technique consists of the insertion of BFRP spikes into timber beams to restore the continuity of cracked sections. The experimental efforts deal with the evaluation of the bending strength and deformation properties of 24 timber beams. An artificially simulated cracking was produced by cutting the wood beams in half or notching. The obtained results for the repaired beams were compared with those of solid undamaged and damaged beams, and increases of beam capacity, bending strength and of modulus of elasticity, and analysis of failure modes was discussed. For notched beams, the application of the BFRP spikes was able to restore the original bending capacity of undamaged beams, while only a small part of the original capacity was recovered for beams that were cut in half.

  2. Radiolytic hydrogen production in the subseafloor basaltic aquifer

    Directory of Open Access Journals (Sweden)

    Mary E Dzaugis

    2016-02-01

    Full Text Available Hydrogen (H2 is produced in geological settings by dissociation of water due to radiation from radioactive decay of naturally occurring uranium (238U, 235U, thorium (232Th and potassium (40K. To quantify the potential significance of radiolytic H2 as an electron donor for microbes within the South Pacific subseafloor basaltic aquifer, we use radionuclide concentrations of 43 basalt samples from IODP Expedition 329 to calculate radiolytic H2 production rates in basement fractures. The samples are from three sites with very different basement ages and a wide range of alteration types. U, Th and K concentrations vary by up to an order of magnitude from sample to sample at each site. Comparison of our samples to each other and to the results of previous studies of unaltered East Pacific Rise basalt suggests that significant variations in radionuclide concentrations are due to differences in initial (unaltered basalt concentrations (which can vary between eruptive events and post-emplacement alteration. In our samples, there is no clear relationship between alteration type and calculated radiolytic yields. Local maxima in U, Th, and K produce hotspots of H2 production, causing calculated radiolytic rates to differ by up to a factor of 80 from sample to sample. Fracture width also greatly influences H2 production, where microfractures are hotspots for radiolytic H2 production. For example, H2 production rates normalized to water volume are 190 times higher in 1 μm wide fractures than in fractures that are 10 cm wide. To assess the importance of water radiolysis for microbial communities in subseafloor basaltic aquifers, we compare electron transfer rates from radiolysis to rates from iron oxidation in subseafloor basalt. Radiolysis appears likely to be a more important electron donor source than iron oxidation in old (>10 Ma basement basalt. Radiolytic H2 production in the volume of water adjacent to a square cm of the most radioactive SPG basalt may

  3. Geochemistry of the Potassic Basalts from the Bufumbira Volcanic ...

    African Journals Online (AJOL)

    The various basalts are low in SiO2 wt %, Al2O3 wt % and Na2O wt % but high in MgO wt %, TiO2 wt %, CaO wt %, K2O wt % with K2O/Na2O = 1.08 to 2.07. These are potassic belonging to the kamafugite series. Plots discriminate two geochemical trends corresponding to the picritic and clinopyroxene rich basalts.

  4. Mechanical Characterization of Basalt and Glass Fiber Epoxy Composite Tube

    OpenAIRE

    Lapena, Mauro Henrique; Marinucci, Gerson

    2017-01-01

    The application of basalt fibers are possible in many areas thanks to its multiple and good properties. It exhibits excellent resistance to alkalis, similar to glass fiber, at a much lower cost than carbon and aramid fibers. In the present paper, a comparative study on mechanical properties of basalt and E-glass fiber composites was performed. Results of apparent hoop tensile strength test of ring specimens cut from tubes and the interlaminar shear stress (ILSS) test are presented. Tensile te...

  5. Implications of Zn/Fe ratios for the sources of Colorado Plateau basalts

    Science.gov (United States)

    Rudzitis, S.; Reid, M. R.

    2011-12-01

    Early Miocene to recent mafic magmatism migrated across the Arizona Transition Zone towards the center of the stable Colorado Plateau at a rate of ~ 3-6 km/Myr (Roy et al., 2009). Present-day volcanic centers are close to a stepwise change in the thickness of the lithosphere between the Colorado Plateau and Basin and Range. Accordingly, volcanic migration might track progressive thinning of the lithosphere towards the center of the Colorado Plateau. This project aims to determine the conditions of melt generation across the transition zone in order to investigate the temporal/spatial correlation between volcanism and thinning of the Colorado Plateau lithosphere. Pressure and temperature estimates for Colorado Plateau basalts can be obtained from the Mg and Si contents of melts (Lee et al, 2009) but require melting of a peridotitic source. Eclogite and pyroxenite xenoliths reported in Colorado Plateau basalts show that melt sources could be olivine-poor. Zn/Fe ratios in melts can help to distinguish contributions from olivine-poor sources because they are sensitive to differences in bulk chemistry and to mineralogy (Le Roux et al., 2010). Specifically, Zn/Fe is not fractionated between melt, olivine, and orthopyroxene, but is highly fractionated when clinopyroxene and garnet are present. Our work to date has focused on laser ablation-IC-PMS analysis of individual olivine grains from high-Mg basalts (>8.0 wt. %) from the San Francisco and Mormon Mountain volcanic fields. Preliminary values of Zn/Fe ratios that represent the averages of multiple analyses of several grains in individual samples range from 7.9 to 9.3 (x10000). Variations of up to 1.7 (x10000) in the ratios exist between individual grains within samples and could be the result of co-crystallization of clinopyroxene with olivine. The lowest values in each sample should approach the Zn/Fe ratios of parental melts, and are, in turn, similar to MORB values and predicted peridotite melts. The results suggest

  6. Paleoclimatic and paleoenvironmental records of the Oligocene-Miocene transition, central Jylland, Denmark

    NARCIS (Netherlands)

    Sliwinska, K.K.; Dybkjær, K.; Schoon, P.L.; Beyer, C.; King, C.; Schouten, S.; Nielsen, O.B.

    2014-01-01

    A multidisciplinary study of the Oligocene/Miocene (O/M) transition was carried in two boreholes (Harre-1 and Horn-1) from the Danish land area in order to improve the understanding of the paleodimatological and environmental changes across the Mi-1, the earliest Miocene cooling event.

  7. Miocene fish faunas from the northwestern Amazonia basin (Colombia, Peru, Brazil) with evidence of marine incursions

    NARCIS (Netherlands)

    Monsch, KA

    1998-01-01

    New evidence indicates marine influences during the Miocene in the northwestern Amazonia basin. This is the first major survey of the ichthyofauna from this area in the Miocene. Fossil fish remains from taxa such as the Dasyatoidea, Myliobatoidea, Characiformes, Siluriformes and Sciaenidae are

  8. Facies architecture of basin-margin units in time and space: Lower to Middle Miocene Sivas Basin, Turkey

    Science.gov (United States)

    Çiner, A.; Kosun, E.

    2003-04-01

    The Miocene Sivas Basin is located within a collision zone, forming one of the largest basins in Central Turkey that developed unconformably on a foundered Paleozoic-Mesozoic basement and Eocene-Oligocene deposits. The time and space relationships of sedimentary environments and depositional evolution of Lower to Middle Miocene rocks exposed between Zara and Hafik towns is studied. A 4 km thick continuous section is subdivided into the Agilkaya and Egribucak Formations. Each formation shows an overall fining upward trend and contains three members. Although a complete section is present at the western part (near Hafik) of the basin, to the east the uppermost two members (near Zara) are absent. The lower members of both formations are composed of fluvial sheet-sandstone and red mudstone that migrate laterally on a flood basin within a semi-arid fan system. In the Agilkaya Formation that crops out near Zara, alluvial fans composed of red-pink volcanic pebbles are also present. The middle members are composed of bedded to massive gypsum and red-green mudstone of a coastal and/or continental sabkha environment. While the massive gypsum beds reach several 10’s of m in Hafik area, near Zara, they are only few m thick and alternate with green mudstones. In Hafik, bedded gypsums are intercalated with lagoonal dolomitic limestone and bituminous shale in the Agilkaya Formation and with fluvial red-pink sandstone-red mudstone in the Egribucak Formation. The upper members are made up of fossiliferous mudstone and discontinuous sandy limestone beds with gutter casts, HCS, and 3-D ripples. They indicate storm-induced sedimentation in a shallow marine setting. The disorganized accumulations of ostreid and cerithiid shells, interpreted as coquina bars, are the products of storm generated reworking processes in brackish environments. Rapid vertical and horizontal facies changes and the facies associations in both formations reflect the locally subsiding nature of this molassic

  9. High alkali-resistant basalt fiber for reinforcing concrete

    International Nuclear Information System (INIS)

    Lipatov, Ya.V.; Gutnikov, S.I.; Manylov, M.S.; Zhukovskaya, E.S.; Lazoryak, B.I.

    2015-01-01

    Highlights: • Doping of basalt fiber with ZrSiO 4 increased its alkali resistance. • Alkali treatment results in formation of protective surface layer on fibers. • Morphology and chemical composition of surface layer were investigated. • Mechanical properties of fibers were analyzed by a Weibull distribution. • Zirconia doped basalt fibers demonstrate high performance in concrete. - Abstract: Basalt glasses and fibers with zirconia content in the range from 0 to 7 wt% were obtained using ZrSiO 4 as a zirconium source. Weight loss and tensile strength loss of fibers after refluxing in alkali solution were determined. Basalt fiber with 5.7 wt% ZrO 2 had the best alkali resistance properties. Alkali treatment results in formation of protective surface layer on fibers. Morphology and chemical composition of surface layer were investigated. It was shown that alkali resistance of zirconia doped basalt fibers is caused by insoluble compounds of Zr 4+ , Fe 3+ and Mg 2+ in corrosion layer. Mechanical properties of initial and leached fibers were evaluated by a Weibull distribution. The properties of basalt fibers with ZrSiO 4 were compared with AR-glass fibers. The performance of concrete with obtained fibers was investigated

  10. Tropical sea surface temperature variability near the Oligocene - Miocene boundary

    Science.gov (United States)

    Zhang, Y.; Pagani, M.

    2010-12-01

    The Oligocene/Miocene (O-M) boundary is characterized by a period of rapid and intense glaciation labeled Mi-1 at ~ 23.1 Ma. An abrupt 1.5‰ increase in the benthic foraminifera oxygen isotope composition that characterizes Mi-1 may indicate a (1) significant deep-water temperature decrease; (2) major ice-sheet expansion, or the combination of both. Current coarse Mg/Ca-based temperature estimations for the early Miocene suggests that deep-ocean temperatures were ~2°C warmer than Today [1, 2]. However, Mg/Ca based temperatures can also be influenced by changes in the carbonate ion concentration, vital effects, and diagenesis. In particular, recent evidence from mid-ocean ridge flank carbonate veins shows dramatic seawater Mg/Ca ratio changes during the Neogene (Mg/Ca from ~2.2 to 5.3, [3]), which further challenges the application of Mg/Ca thermometry. Owing to poor temperature constraints, current ice volume estimations for the late Oligocene/early Miocene range from 125% of the present-day East Antarctic Ice Sheet (EAIS) to a nearly complete collapse of the Antarctic glaciers [4]. Here we present tropical sea surface temperatures (SSTs) records based on TEX86 and alkenone UK37 near the O-M boundary. Sediment samples from Ocean Drilling Program (ODP) Site 926 in the Ceara Rise (tropical Atlantic) and Site 1148 in the South China Sea (tropical Pacific) were subject to lipid extraction, separation, gas chromatography, and liquid chromatography-mass spectrometry analysis. TEX86-based SST indicates that the tropics were ~3-4°C warmer than today and relatively stable during Mi-1. This suggests that ice-sheet dynamics, rather than temperature, might be responsible for the observed oxygen isotope changes during the O-M boundary. Further, O-M boundary averaged temperatures recorded at site 926 is ~ 0.5°C higher relative to the late Eocene from site 925 (a nearby site [5]). Given late Oligocene benthic δ18O that suggests at least 1‰ enrichment relative to the late

  11. Health impacts of floods.

    Science.gov (United States)

    Du, Weiwei; FitzGerald, Gerard Joseph; Clark, Michele; Hou, Xiang-Yu

    2010-01-01

    Floods are the most common hazard to cause disasters and have led to extensive morbidity and mortality throughout the world. The impact of floods on the human community is related directly to the location and topography of the area, as well as human demographics and characteristics of the built environment. The aim of this study is to identify the health impacts of disasters and the underlying causes of health impacts associated with floods. A conceptual framework is developed that may assist with the development of a rational and comprehensive approach to prevention, mitigation, and management. This study involved an extensive literature review that located >500 references, which were analyzed to identify common themes, findings, and expert views. The findings then were distilled into common themes. The health impacts of floods are wide ranging, and depend on a number of factors. However, the health impacts of a particular flood are specific to the particular context. The immediate health impacts of floods include drowning, injuries, hypothermia, and animal bites. Health risks also are associated with the evacuation of patients, loss of health workers, and loss of health infrastructure including essential drugs and supplies. In the medium-term, infected wounds, complications of injury, poisoning, poor mental health, communicable diseases, and starvation are indirect effects of flooding. In the long-term, chronic disease, disability, poor mental health, and poverty-related diseases including malnutrition are the potential legacy. This article proposes a structured approach to the classification of the health impacts of floods and a conceptual framework that demonstrates the relationships between floods and the direct and indirect health consequences.

  12. A macroecological glance at the structure of late Miocene rodent assemblages from Southwest Europe

    Science.gov (United States)

    Cano, Ana Rosa Gómez; Cantalapiedra, Juan L.; Álvarez-Sierra, M. Ángeles; Fernández, Manuel Hernández

    2014-10-01

    Deep-time perspectives in macroecology are essential with regard to understanding the impact of climate forcing on faunal communities. Using late Miocene rodent faunas (12 to 5 Ma) from two different biogeographical provinces from southwestern Europe, we asked whether the waxing and waning of faunas with dissimilar ecological affinities tracked climate in different ways. The latest middle Miocene featured a fauna dominated by dormice with forest and mixed-habitat affinities. This group declined towards the Upper Miocene. Rodent taxa with the highest values of richness at the beginning of the Upper Miocene are generalists in the southern province and specialists of forested habitats in the northern province. Finally, we identified a third, increasingly significant group of rodents linked to open landscapes towards the end of the Miocene. These three broad ecological groups showed differential responses to a complex set of interconnected circumstances, including the biogeographic structure of the study area and climatic changes throughout time.

  13. Miocene transgression in the central and eastern parts of the Sivas Basin (Central Anatolia, Turkey) and the Cenozoic palaeogeographical evolution

    Science.gov (United States)

    Poisson, André; Vrielynck, Bruno; Wernli, Roland; Negri, Alessandra; Bassetti, Maria-Angela; Büyükmeriç, Yesim; Özer, Sacit; Guillou, Hervé; Kavak, Kaan S.; Temiz, Haluk; Orszag-Sperber, Fabienne

    2016-01-01

    We present here a reappraisal of the tectonic setting, stratigraphy and palaeogeography of the central part of the Sivas Basin from Palaeocene to late Miocene. The Sivas Basin is located in the collision zone between the Pontides (southern Eurasia) and Anatolia (a continental block rifted from Gondwana). The basin overlies ophiolites that were obducted onto Anatolia from Tethys to the north. The Central Anatolian Crystalline Complex (CACC) experienced similar ophiolite obduction during Campanian time, followed by exhumation and thrusting onto previously emplaced units during Maastrichtian time. To the east, crustal extension related to exhumation of the CACC created grabens during the early Tertiary, including the Sivas Basin. The Sivas Basin underwent several tectonic events during Paleogene-Neogene. The basin fill varies, with several sub-basins, each being characterised by a distinctive sequence, especially during Oligocene and Miocene. Evaporite deposition in the central part of the basin during early Oligocene was followed by mid-late Oligocene fluvio-lacustrine deposition. The weight of overlying fluvial sediments triggered salt tectonics and salt diapir formation. Lacustrine layers that are interbedded within the fluviatile sediments have locally yielded charophytes of late Oligocene age. Emergent areas including the pre-existing Sivas Basin and neighbouring areas were then flooded from the east by a shallow sea, giving rise to a range of open-marine sub-basins, coralgal reef barriers and subsiding, restricted-marine sub-basins. Utilising new data from foraminifera, molluscs, corals and nannoplankton, the age of the marine transgression is reassessed as Aquitanian. Specifically, age-diagnostic nannoplankton assemblages of classical type occur at the base of the transgressive sequence. However, classical stratigraphic markers have not been found within the planktic foraminiferal assemblages, even in the open-marine settings. In the restricted-marine sediments

  14. Nogales flood detention study

    Science.gov (United States)

    Norman, Laura M.; Levick, Lainie; Guertin, D. Phillip; Callegary, James; Guadarrama, Jesus Quintanar; Anaya, Claudia Zulema Gil; Prichard, Andrea; Gray, Floyd; Castellanos, Edgar; Tepezano, Edgar; Huth, Hans; Vandervoet, Prescott; Rodriguez, Saul; Nunez, Jose; Atwood, Donald; Granillo, Gilberto Patricio Olivero; Ceballos, Francisco Octavio Gastellum

    2010-01-01

    Flooding in Ambos Nogales often exceeds the capacity of the channel and adjacent land areas, endangering many people. The Nogales Wash is being studied to prevent future flood disasters and detention features are being installed in tributaries of the wash. This paper describes the application of the KINEROS2 model and efforts to understand the capacity of these detention features under various flood and urbanization scenarios. Results depict a reduction in peak flow for the 10-year, 1-hour event based on current land use in tributaries with detention features. However, model results also demonstrate that larger storm events and increasing urbanization will put a strain on the features and limit their effectiveness.

  15. Development of flood index by characterisation of flood hydrographs

    Science.gov (United States)

    Bhattacharya, Biswa; Suman, Asadusjjaman

    2015-04-01

    In recent years the world has experienced deaths, large-scale displacement of people, billions of Euros of economic damage, mental stress and ecosystem impacts due to flooding. Global changes (climate change, population and economic growth, and urbanisation) are exacerbating the severity of flooding. The 2010 floods in Pakistan and the 2011 floods in Australia and Thailand demonstrate the need for concerted action in the face of global societal and environmental changes to strengthen resilience against flooding. Due to climatological characteristics there are catchments where flood forecasting may have a relatively limited role and flood event management may have to be trusted upon. For example, in flash flood catchments, which often may be tiny and un-gauged, flood event management often depends on approximate prediction tools such as flash flood guidance (FFG). There are catchments fed largely by flood waters coming from upstream catchments, which are un-gauged or due to data sharing issues in transboundary catchments the flow of information from upstream catchment is limited. Hydrological and hydraulic modelling of these downstream catchments will never be sufficient to provide any required forecasting lead time and alternative tools to support flood event management will be required. In FFG, or similar approaches, the primary motif is to provide guidance by synthesising the historical data. We follow a similar approach to characterise past flood hydrographs to determine a flood index (FI), which varies in space and time with flood magnitude and its propagation. By studying the variation of the index the pockets of high flood risk, requiring attention, can be earmarked beforehand. This approach can be very useful in flood risk management of catchments where information about hydro-meteorological variables is inadequate for any forecasting system. This paper presents the development of FI and its application to several catchments including in Kentucky in the USA

  16. Legitimizing differentiated flood protection levels

    NARCIS (Netherlands)

    Thomas, Hartmann; Spit, Tejo

    2016-01-01

    The European flood risk management plan is a new instrument introduced by the Floods Directive. It introduces a spatial turn and a scenario approach in flood risk management, ultimately leading to differentiated flood protection levels on a catchment basis. This challenges the traditional sources of

  17. Icelandic basaltic geothermal field: A natural analog for nuclear waste isolation in basalt

    International Nuclear Information System (INIS)

    Ulmer, G.C.; Grandstaff, D.E.

    1984-01-01

    Analog studies of Icelandic geothermal fields have shown that the design of nuclear waste repositories in basalt can benefit by comparison to the data base already available from the development of these geothermal fields. A high degree of similarity exists between these two systems: their petrology, groundwater geochemistry, mineral solubilities, hydrologic parameters, temperature ranges, water-rock redox equilibria, hydrothermal pH values, and secondary mineralogies all show considerable overlap in the range of values. The experimentally-simulated hydrothermal studies of the basaltic nuclear waste repository rocks have, at this time, produced a data base that receives a strong confirmation from the Icelandic analog. Furthermore, the Icelandic analog should eventually be employed to extrapolate into higher and lower temperatures, into longer time-base chemical comparisons, and into more realistic mineral deposition studies, than have been possible in the laboratory evaluations of the nuclear waste repository designs. This eventual use of the Icelandic analog will require cooperative work with the Icelandic Geological Survey. 46 refs., 4 figs., 2 tabs

  18. Geomechanical rock properties of a basaltic volcano

    Directory of Open Access Journals (Sweden)

    Lauren N Schaefer

    2015-06-01

    Full Text Available In volcanic regions, reliable estimates of mechanical properties for specific volcanic events such as cyclic inflation-deflation cycles by magmatic intrusions, thermal stressing, and high temperatures are crucial for building accurate models of volcanic phenomena. This study focuses on the challenge of characterizing volcanic materials for the numerical analyses of such events. To do this, we evaluated the physical (porosity, permeability and mechanical (strength properties of basaltic rocks at Pacaya Volcano (Guatemala through a variety of laboratory experiments, including: room temperature, high temperature (935 °C, and cyclically-loaded uniaxial compressive strength tests on as-collected and thermally-treated rock samples. Knowledge of the material response to such varied stressing conditions is necessary to analyze potential hazards at Pacaya, whose persistent activity has led to 13 evacuations of towns near the volcano since 1987. The rocks show a non-linear relationship between permeability and porosity, which relates to the importance of the crack network connecting the vesicles in these rocks. Here we show that strength not only decreases with porosity and permeability, but also with prolonged stressing (i.e., at lower strain rates and upon cooling. Complimentary tests in which cyclic episodes of thermal or load stressing showed no systematic weakening of the material on the scale of our experiments. Most importantly, we show the extremely heterogeneous nature of volcanic edifices that arise from differences in porosity and permeability of the local lithologies, the limited lateral extent of lava flows, and the scars of previous collapse events. Input of these process-specific rock behaviors into slope stability and deformation models can change the resultant hazard analysis. We anticipate that an increased parameterization of rock properties will improve mitigation power.

  19. Flood-proof motors

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Marcus [AREVA NP GmbH, Erlangen (Germany)

    2013-07-01

    Even before the Fukushima event occurred some German nuclear power plants (NPP) have considered flooding scenarios. As a result of one of these studies, AREVA performed an upgrade project in NPP Isar 1 with flood-proof motors as a replacement of existing air-cooled low-voltage and high-voltage motors of the emergency cooling chain. After the Fukushima event, in which the cooling chains failed, the topic flood-proof equipment gets more and more into focus. This compact will introduce different kinds of flood-proof electrical motors which are currently installed or planned for installation into NPPs over the world. Moreover the process of qualification, as it was performed during the project in NPP Isar 1, will be shown. (orig.)

  20. Floods and Mold Growth

    Science.gov (United States)

    Mold growth may be a problem after flooding. Excess moisture in the home is cause for concern about indoor air quality primarily because it provides breeding conditions for pests, molds and other microorganisms.

  1. FLOODPLAIN, FLOOD COUNTY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

  2. Flood-proof motors

    International Nuclear Information System (INIS)

    Schmitt, Marcus

    2013-01-01

    Even before the Fukushima event occurred some German nuclear power plants (NPP) have considered flooding scenarios. As a result of one of these studies, AREVA performed an upgrade project in NPP Isar 1 with flood-proof motors as a replacement of existing air-cooled low-voltage and high-voltage motors of the emergency cooling chain. After the Fukushima event, in which the cooling chains failed, the topic flood-proof equipment gets more and more into focus. This compact will introduce different kinds of flood-proof electrical motors which are currently installed or planned for installation into NPPs over the world. Moreover the process of qualification, as it was performed during the project in NPP Isar 1, will be shown. (orig.)

  3. Geochemical Consequences of Lithospheric Delamination in the Eastern Mediterranean: Evidence From Young Turkish Basalts

    Science.gov (United States)

    Furman, T.; Kurkcuoglu, B.; Plummer, C.

    2007-12-01

    Magmatism associated with continental collision is increasingly attributed to major disturbance of or within the lithosphere. Geochemical and isotopic data on post-collisional primitive mafic lavas from across the Anatolian plate enable us to assess the effects of lithospheric delamination (slab rollback and breakoff) as indicated by geophysical studies. The Anatolian province displays geodynamically complex manifestations of the closure of neo-Tethys and the collision between Africa and Europe that commenced circa 30 Ma. The current south- southwestward motion of Anatolia, a.k.a. "Turkish escape", is accommodated by slab rollback along the Hellenic trench and orogenic collapse along both the eastern and western margins of the microplate. Volcanism occurs primarily along the fault zones that border and cross-cut Anatolia, and major element characteristics of the lavas vary with both space and time. In Western Anatolia, early Miocene collisional calc- alkaline magmatism was followed by Quaternary alkaline volcanism (Alici et al. 1998, 2002; Aldanmaz et al. 2000, 2006) related to orogenic collapse, presumably resulting from slab rollback. Orogenic collapse in Eastern Anatolia is facilitated by slab breakoff as determined by geophysical studies (Zor et al. 2003; Angus et al. 2006; Lei & Zhao 2007). This transition was accompanied a change from mid-Miocene calc-alkaline to Quaternary alkaline volcanism (e.g., Yilmaz 1990; Pearce et al. 1990). Central Anatolia displays calc-alkaline and tholeiitic volcanism, including alkali olivine basalts; plate tectonic reconstructions (Lyberis et al. 1992) indicate that the African slab did not reach Central Anatolia. Sr-Nd isotope values from each volcanic province define linear arrays that converge upon a common unradiogenic value typical of global depleted mantle. We suggest that mafic volcanism throughout Anatolia is supported by a common asthenospheric component, modified by identifiable, location-specific additions. In areas

  4. Flood hazard assessment in areas prone to flash flooding

    Science.gov (United States)

    Kvočka, Davor; Falconer, Roger A.; Bray, Michaela

    2016-04-01

    Contemporary climate projections suggest that there will be an increase in the occurrence of high-intensity rainfall events in the future. These precipitation extremes are usually the main cause for the emergence of extreme flooding, such as flash flooding. Flash floods are among the most unpredictable, violent and fatal natural hazards in the world. Furthermore, it is expected that flash flooding will occur even more frequently in the future due to more frequent development of extreme weather events, which will greatly increase the danger to people caused by flash flooding. This being the case, there will be a need for high resolution flood hazard maps in areas susceptible to flash flooding. This study investigates what type of flood hazard assessment methods should be used for assessing the flood hazard to people caused by flash flooding. Two different types of flood hazard assessment methods were tested: (i) a widely used method based on an empirical analysis, and (ii) a new, physically based and experimentally calibrated method. Two flash flood events were considered herein, namely: the 2004 Boscastle flash flood and the 2007 Železniki flash flood. The results obtained in this study suggest that in the areas susceptible to extreme flooding, the flood hazard assessment should be conducted using methods based on a mechanics-based analysis. In comparison to standard flood hazard assessment methods, these physically based methods: (i) take into account all of the physical forces, which act on a human body in floodwater, (ii) successfully adapt to abrupt changes in the flow regime, which often occur for flash flood events, and (iii) rapidly assess a flood hazard index in a relatively short period of time.

  5. CO{sub 2} mineral trapping: an experimental study on the carbonation of basalts from the eastern Deccan Volcanic Province, India

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Nishi; Pathak, Vamdev; Shrivastava, J.P. [Department of Geology, University of Delhi, Delhi 110007 (India)

    2013-07-01

    Rock specimens from Deccan flood basalts have been reacted in the laboratory under high pCO{sub 2} (5 and 10 bars), total pressure (vessel pressure between 10 and 20 bars), and temperature (100 and 200 deg. C) conditions for 50, 60, 70, and 80 hours. XRD and SEM-EDS analyses show that calcite, aragonite, siderite and magnesite, and clays are derived from the alteration of Deccan basalts under water-saturated, hydrothermal-like conditions. Alteration reactions were accompanied by significant variation in the pH of the reacting aqueous solution, dependent upon time, pCO{sub 2}, and temperature variables of the experiment. Neo-formed secondary products also include significant amounts of smectite, chlorite, and smectite/chlorite mixed layer clays. (authors)

  6. Comments to Middle Miocene closure of the Central American Seaway

    Science.gov (United States)

    Coates, A.G.; Stallard, Robert F.

    2016-01-01

    In a recent paper proposing an early (mid-Miocene) closure of the Central American Seaway (CAS), Montes et al. 2015 (1) disregard existing paleogeographic data that invalidate Panama as a source for zircons, and inappropriately ignore the evidence for trans-isthmian marine connections until 4-3 Ma. They also fail to cite previous work (2, 3), that had reconstructed the Central American arc already docked with South America by 12 Ma. Montes et al. 2015 (1) (Fig. 1) disregard the Atrato-San Juan sedimentary basin (3), a shallowing Oligocene to Pliocene, Pacific to Caribbean seaway (3, 4, 5). This deep graben (6) is filled with thousands of meters of Pre-Pliocene marine sediments (3, 5, 6) that now occupy a lowland between the Baudo uplift to the west and the Western Cordillera to the east. The Mande Batholith and numerous Eocene and younger volcanic rocks (4), the most proximal source of the zircons, are situated to the east of this seaway and would have shed zircons eastward towards the Cordillera Central. There is no evidence for any rivers crossing the seaway (3, 5), and thus no Panamanian source of zircons. Instead this seaway is evidence of a significant marine connection between the Pacific and Atlantic oceans into the Pliocene. The authors assume that the middle Miocene closure of the CAS effectively creates a continuous land bridge connecting North and South America and separating the Atlantic from the Pacific. They acknowledge, but then discount, marine connections across the Isthmus until 4-3 Ma even though these satisfactorily explain (Coates and Stallard, 2014 (6)) the oceanographic, molecular and Great American Biological Interchange events ignore unexplained by Montes et al. 2015. Only by conspicuously ignoring these events can they imply that the Isthmus was formed at 15-13 Ma. References 1. C. Montes et al., Middle Miocene closure of the Central American Seaway. Science 348, 226-229 (2015). 2. A. G. Coates, R. F. Stallard, How old is the Isthmus of

  7. Surface oxidization-reduction reactions in Columbia Plateau basalts

    International Nuclear Information System (INIS)

    White, A.F.; Yee, A.

    1984-01-01

    Results are presented which define principal oxidation-reduction reactions expected between ground water and iron in the Umtanum and Cohassett basalt flows of south central Washington. Data include kinetics of aqueous iron speciation, rates of O 2 uptake and nature of oxyhydroxide precipitates. Such data are important in predicting behavior of radionuclides in basalt aquifers including determination of valence states, speciation, solubility, sorption, and coprecipitation on iron oxyhydroxide substrates and colloids. Analyses of the basalt by XPS indicates that ferrous iron is oxidized to ferric iron on the surface and that the total iron decreases as a function of pH during experimental weathering. Iron oxyhydroxide phases did not form surface coating on basalt surfaces but rather nucleated as separate plases in solution. No significant increases in Cs or Sr sorption were observed with increased weathering of the basalt. Concurrent increases in Fe(II) and decreases in Fe(III) in slightly to moderately acid solutions indicated continued oxidization of ferrous iron in the basalt. At neutral to basic pH, Fe(II) was strongly sorbed onto the basalt surface (Kd = 6.5 x 10 -3 1 x m 2 ) resulting in low dissolved concentrations even under anoxic conditions. The rate of O 2 uptake increased with decreasing pH. Diffusion rates (-- 10 -14 cm 2 x s -1 ), calculated using a one-dimensional analytical model, indicate grain boundary diffusion. Comparisons of Eh values calculated by Pt electrode, dissolved O 2 and Fe(II)/Fe(III) measurements showed considerable divergence, with the ferric-ferrous couple being the preferred method of estimating Eh

  8. Precipitation history of the central Atacama Desert since the Miocene as reconstructed from clay pan records of the Costal Cordillera/ N Chile

    Science.gov (United States)

    Wennrich, V.; Melles, M.; Diederich, J. L.; Fernández Galego, E.; Ritter, B.; Brill, D.; Niemann, K.; Rolf, C.; Dunai, T. J.

    2017-12-01

    Hyperaridity is a major limitation of Earth-surface processes and biological activity in the Atacama Desert of N Chile, one of the oldest and the driest deserts on Earth. But even the hyperarid core of the Atacama Desert of N Chile has experienced sever precipitation events, e.g., during the flash floods in 2015. On geological timescales, the overall aridity that is postulated to have lasted at least since the early Miocene was punctuated by distinct pluvial events. Such wetter conditions, e.g. during the Miocene, caused widespread lake-formation in the Central Depression and Coastal Cordillera, but also caused amplified surface processes, changes in vegetation dynamics, and enabled the dispersal of species. Unfortunately, due to the limited number and heterogeneous appearance of climate archives from the central Atacama, it's longer-scale precipitation history is still a matter of controversy. This study aims to study continuous longterm (Pleistocene-Miocene) paleoclimatic and environmental records from the hyperarid core of the Atacama Desert covering the last >10 Ma. Therefor we investigate clay pans records from endorheic basins in the Coastal Cordillera mostly formed by blocking of drainage by tectonic movement. The clay pans under study are located along a latitudinal transect across the hyperarid core of the Atacama, and thus, are assumed to have recorded local and regional precipitation variations on different timescales. The investigated sequences exhibit significant changes in the sedimentological, geochemical, and mineralogical properties due to changes in precipitation, but also in the weathering and erosion in the catchments. Diatom and phytolith remains preserved in these records clearly point to significant water bodies during the wettest periods and a significant vegetation cover. The results shed a new light on the timing, frequency, and the driving mechanisms of the intervening pluvial phases.

  9. EARLY MIOCENE INSULAR VERTEBRATES FROM LAERRU (SARDINIA, ITALY: PRELIMINARY NOTE

    Directory of Open Access Journals (Sweden)

    DANIEL ZOBOLI

    2017-01-01

    Full Text Available A new vertebrate assemblage was discovered in an Early  Miocene lacustrine deposit near the village of Laerru (northern Sardinia, Italy. The assemblage is composed by mammals, reptiles and a bird. The mammals are represented by three ruminants (cf. Sardomeryx oschiriensis, Pecora indet. small size and Pecora indet. very small size and one dormouse (Peridyromys aff. murinus while reptiles are represented by turtles (Trionychidae? and crocodiles (cf. Diplocynodon sp.. A bird bone fragment is also reported and referred to Palaeortyx cf. brevipes (Galliformes. The assemblage can be related to the “Oschiri fauna”, one of the oldest endemic insular fauna known in the Mediterranean. The age of the Laerru vertebrates is early-middle Burdigalian, between 18.8 and 18.3 Ma, corresponding to the mammal unit of the main land MN3. The predominance of ruminants confirms the good capacity of these mammals to colonize insular environments.

  10. Quantifying the Effects of Spatial Uncertainty in Fracture Permeability on CO2 Leakage through Columbia River Basalt Flow Interiors

    Science.gov (United States)

    Gierzynski, A.; Pollyea, R.

    2016-12-01

    Recent studies suggest that continental flood basalts may be suitable for geologic carbon sequestration, due to fluid-rock reactions that mineralize injected CO2 on relatively short time-scales. Flood basalts also possess a morphological structure conducive to injection, with alternating high-permeability (flow margin) and low-permeability (flow interior) layers. However, little information exists on the behavior of CO2 migration within field-scale fracture networks, particularly within flow interiors and at conditions near the critical point for CO2. In this study, numerical simulation is used to investigate the influence of fracture permeability uncertainty during gravity-driven CO2 migration within a jointed basalt flow interior as CO2 undergoes phase change from supercritical fluid to a subcritical phase. The model domain comprises a 2D fracture network mapped with terrestrial LiDAR scans of Columbia River Basalt acquired near Starbuck, WA. The model domain is 5 m × 5 m with bimodal heterogeneity (fracture and matrix), and initial conditions corresponding to a hydrostatic pressure gradient between 750 and 755 m depth. Under these conditions, the critical point for CO2 occurs 1.5 m above the bottom of the domain. For this model scenario, CO2 enters the base of the fracture network at 0.5 MPa overpressure, and matrix permeability is assumed constant. Fracture permeability follows a lognormal distribution on the basis of fracture aperture values from literature. In order to account for spatial uncertainty, the lognormal fracture permeability distribution is randomly located in the model domain and CO2 migration is simulated within the same fracture network for 50 equally probable realizations. Model results suggest that fracture connectivity, which is independent of permeability distribution, governs the path taken by buoyant CO2 as it rises through the flow interior; however, the permeability distribution strongly governs the CO2 flux magnitude. In particular

  11. The subcontinental mantle beneath southern New Zealand, characterised by helium isotopes in intraplate basalts and gas-rich springs

    Science.gov (United States)

    Hoke, L.; Poreda, R.; Reay, A.; Weaver, S. D.

    2000-07-01

    relationship with either age or proximity to the Cenozoic intraplate volcanic centres or with major faults. In general, areas characterised by mantle 3He emission are interpreted to define those regions beneath which mantle melting and basalt magma addition to the crust are recent. The strongest mantle 3He anomaly (equivalent to >80% mantle helium component) is centred over southern Dunedin, measured in magmatic CO 2-rich mineral water springs issuing from crystalline basement rocks which outcrop at the southern extent of Miocene intraplate basaltic volcanism which ceased 9 Ma ago. This mantle helium anomaly overlaps with an area characterised by elevated surface high heat flow, compatible with a long-lived mantle melt/heat input into the crust. In comparison Banks Peninsula, another Miocene intraplate basaltic centre, is characterised by relatively low surface heat flow and a small mantle helium contribution measured in a nitrogen-rich spring. Here the thermal transient induced by the magmatic event has either dissipated or has not reached the surface. In the former case one might be dealing with storage and mixing of magmatic and crustal gases at shallow crustal levels and in the latter with active to recent mantle-melt degassing at depth. Along the most actively deforming part of the plate boundary zone, the transpressional Alpine Fault and Marlborough fault systems, mantle helium is present in gas-rich springs in all those areas underlain by actively subducting oceanic crust (the Australian plate in the south and Pacific plate in the north), whereas the central part of the Alpine transpressional fault is characterised by pure crustal radiogenic helium. Areas where the mantle helium component is negligible are restricted to the centre part of the South Island, extending along its length from Southland to northern Canterbury and Murchison. These areas are interpreted to delineate the extent of thicker and colder lithosphere compared to all other areas where mantle helium

  12. Changing seasonality patterns in Central Europe from Miocene Climate Optimum to Miocene Climate Transition deduced from the Crassostrea isotope archive

    Science.gov (United States)

    Harzhauser, Mathias; Piller, Werner E.; Müllegger, Stefan; Grunert, Patrick; Micheels, Arne

    2011-03-01

    The Western Tethyan estuarine oyster Crassostrea gryphoides is an excellent climate archive due to its large size and rapid growth. It is geologically long lived and allows a stable isotope-based insight into climatic trends during the Miocene. Herein we utilised the climate archive of 5 oyster shells from the Miocene Climate Optimum (MCO) and the subsequent Miocene Climate Transition (MCT) to evaluate changes of seasonality patterns. MCO shells exhibit highly regular seasonal rhythms of warm-wet and dry-cool seasons. Optimal conditions resulted in extraordinary growth rates of the oysters. δ 13C profiles are in phase with δ 18O although phytoplankton blooms may cause a slight offset. Estuarine waters during the MCO in Central Europe display a seasonal temperature range of c. 9-10 °C. Absolute water temperatures have ranged from 17 to 19 °C during cool seasons and up to 28 °C in warm seasons. Already during the early phase of the MCO, the growth rates are distinctly declining, although gigantic and extremely old shells have been formed at that time. Still, a very regular and well expressed seasonality is dominating the isotope profiles, but episodically occurring extreme climate events influence the environments. The seasonal temperature range is still c. 9 °C but the cool season temperature seems to be slightly lower (16 °C) and the warm season water temperature does not exceed c. 25 °C. In the later MCT at c. 12.5-12.0 Ma the seasonality pattern is breaking down and is replaced by successions of dry years with irregular precipitation events. No correlation between δ 18O and δ 13C is documented maybe due to a suboptimal nutrition level which would explain the low growth rates and small sizes. The amplitude of seasonal temperature range is decreasing to 5-8 °C. No clear cooling trend can be postulated for that time as the winter season water temperatures range from 15 to 20 °C. This may point to unstable precipitation rhythms on a multi-annual to

  13. Gulf of Mexico miocene CO₂ site characterization mega transect

    Energy Technology Data Exchange (ETDEWEB)

    Meckel, Timothy [Univ. of Austin, Austin, TX (United Staes); Trevino, Ramon [Univ. of Austin, Austin, TX (United Staes)

    2014-12-01

    This project characterized the Miocene-age sub-seafloor stratigraphy in the near-offshore portion of the Gulf of Mexico adjacent to the Texas coast. The large number of industrial sources of carbon dioxide (CO₂) in coastal counties and the high density of onshore urbanization and environmentally sensitive areas make this offshore region extremely attractive for long-term storage of carbon dioxide emissions from industrial sources (CCS). The study leverages dense existing geologic data from decades of hydrocarbon exploration in and around the study area to characterize the regional geology for suitability and storage capacity. Primary products of the study include: regional static storage capacity estimates, sequestration “leads” and prospects with associated dynamic capacity estimates, experimental studies of CO₂-brine-rock interaction, best practices for site characterization, a large-format ‘Atlas’ of sequestration for the study area, and characterization of potential fluid migration pathways for reducing storage risks utilizing novel high-resolution 3D (HR3D) seismic surveys. In addition, three subcontracted studies address source-to-sink matching optimization, offshore well bore management and environmental aspects. The various geologic data and interpretations are integrated and summarized in a series of cross-sections and maps, which represent a primary resource for any near-term commercial deployment of CCS in the area. The regional study characterized and mapped important geologic features (e.g., Clemente-Tomas fault zone, the regionally extensive Marginulina A and Amphistegina B confining systems, etc.) that provided an important context for regional static capacity estimates and specific sequestration prospects of the study. A static capacity estimate of the majority of the Study area (14,467 mi2) was estimated at 86 metric Gigatonnes. While local capacity estimates are likely to be lower due to reservoir-scale characteristics, the

  14. Diffusion of hydrous species in model basaltic melt

    Science.gov (United States)

    Zhang, Li; Guo, Xuan; Wang, Qinxia; Ding, Jiale; Ni, Huaiwei

    2017-10-01

    Water diffusion in Fe-free model basaltic melt with up to 2 wt% H2O was investigated at 1658-1846 K and 1 GPa in piston-cylinder apparatus using both hydration and diffusion couple techniques. Diffusion profiles measured by FTIR are consistent with a model in which both molecular H2O (H2Om) and hydroxyl (OH) contribute to water diffusion. OH diffusivity is roughly 13% of H2Om diffusivity, showing little dependence on temperature or water concentration. Water diffusion is dominated by the motion of OH until total H2O (H2Ot) concentration reaches 1 wt%. The dependence of apparent H2Ot diffusivity on H2Ot concentration appears to be overestimated by a previous study on MORB melt, but H2Ot diffusivity at 1 wt% H2Ot in basaltic melt is still greater than those in rhyolitic to andesitic melts. The appreciable contribution of OH to water diffusion in basaltic melt can be explained by enhanced mobility of OH, probably associated with the development of free hydroxyl bonded with network-modifying cations, as well as higher OH concentration. Calculation based on the Nernst-Einstein equation demonstrates that OH may serve as an effective charge carrier in hydrous basaltic melt, which could partly account for the previously observed strong influence of water on electrical conductivity of basaltic melt.

  15. Stratigraphy of Oceanus Procellarum basalts - Sources and styles of emplacement

    Science.gov (United States)

    Whitford-Stark, J. L.; Head, J. W., III

    1980-01-01

    The basaltic fill of Oceanus Procellarum has been formally subdivided into four lithostratigraphic formations: The Repsold Formation, the Telemann Formation, the Hermann Formation, and the Sharp Formation. The Repsold Formation is composed of high-Ti basalts and pyroclastic deposits with an estimated age of 3.75 + or - 0.05 b.y. and an estimated volume of about 2.1 x 10 to the 5th cu km. This is overlain by the Telemann Formation composed of very low-Ti basalts and pyroclastic deposits with an estimated age of 3.6 + or - 0.2 b.y. and a volume of 4.2 x 10 to the 5th cu km. The Hermann Formation, composed of intermediate basalts with an estimated age of 3.3 + or - 0.3 b.y., represents the next youngest unit with an estimated volume of 2.2 x 10 to the 5th cu km. The youngest materials in Procellarum are the medium-to-high-Ti basalts comprising the Sharp Formation with an estimated age of 2.7 + or - 0.7 b.y. and a volume of 1.8 x 10 to the 4th cu km.

  16. Similar microbial communities found on two distant seafloor basalts

    Directory of Open Access Journals (Sweden)

    Esther eSinger

    2015-12-01

    Full Text Available The oceanic crust forms two thirds of the Earth’s surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lō’ihi Seamount, Hawai’i, and the East Pacific Rise (EPR (9˚N. Phylogenetic analysis indicates the presence of a total of 43 bacterial and archaeal mono-phyletic groups, dominated by Alpha- and Gammaproteobacteria, as well as Thaumarchaeota. Functional gene analysis suggests that these Thaumarchaeota play an important role in ammonium oxidation on seafloor basalts. In addition to ammonium oxidation, the seafloor basalt habitat reveals a wide spectrum of other metabolic potentials, including CO2 fixation, denitrification, dissimilatory sulfate reduction, and sulfur oxidation. Basalt communities from Lō’ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy.

  17. Canyon formation constraints on the discharge of catastrophic outburst floods of Earth and Mars

    Science.gov (United States)

    Lapotre, Mathieu G. A.; Lamb, Michael P.; Williams, Rebecca M. E.

    2016-07-01

    Catastrophic outburst floods carved amphitheater-headed canyons on Earth and Mars, and the steep headwalls of these canyons suggest that some formed by upstream headwall propagation through waterfall erosion processes. Because topography evolves in concert with water flow during canyon erosion, we suggest that bedrock canyon morphology preserves hydraulic information about canyon-forming floods. In particular, we propose that for a canyon to form with a roughly uniform width by upstream headwall retreat, erosion must occur around the canyon head, but not along the sidewalls, such that canyon width is related to flood discharge. We develop a new theory for bedrock canyon formation by megafloods based on flow convergence of large outburst floods toward a horseshoe-shaped waterfall. The model is developed for waterfall erosion by rock toppling, a candidate erosion mechanism in well fractured rock, like columnar basalt. We apply the model to 14 terrestrial (Channeled Scablands, Washington; Snake River Plain, Idaho; and Ásbyrgi canyon, Iceland) and nine Martian (near Ares Vallis and Echus Chasma) bedrock canyons and show that predicted flood discharges are nearly 3 orders of magnitude less than previously estimated, and predicted flood durations are longer than previously estimated, from less than a day to a few months. Results also show a positive correlation between flood discharge per unit width and canyon width, which supports our hypothesis that canyon width is set in part by flood discharge. Despite lower discharges than previously estimated, the flood volumes remain large enough for individual outburst floods to have perturbed the global hydrology of Mars.

  18. POLYPLACOPHORA FROM THE MIOCENE OF NORTH ITALY. PART 2: CALLOCHITONIDAE, CHITONIDAE, LEPIDOCHITONIDAE, ACANTHOCHITONIDAE AND CRYPTOPLACIDAE

    Directory of Open Access Journals (Sweden)

    BRUNO DELL’ ANGELO

    2016-10-01

    Full Text Available This study completes the description of the chiton fauna (Mollusca, Polyplacophora from deposits of the Miocene marine sequence of North Italy, located in Piedmont and Emilia Romagna regions. This second and final part describes chitons belonging to five families: Callochitonidae, Chitonidae, Lepidochitonidae, Acanthochitonidae and Cryptoplacidae. Nineteen species were identified, of which two are described as new (Chiton sulcomarginatus sp. n. and Craspedochiton brunettii sp. n., and 17 were already known. Craspedochiton mutinocrassus is the new name attributed to the species previously known as Acanthochiton costatus or A. costatus var. mutinocrassa; Chiton sulcomarginatus sp. n., Lepidochitona monterosatoi, L. pliocinerea, and Acanthochitona oblonga, previously known only up to Pliocene, are reported for the first time from the Miocene of Italy. The stratigraphic distribution of numerous species thought to first appear in the Late Miocene (Callochiton doriae, Chiton olivaceus, C. corallinus, Acanthochitona fascicularis, A. crinita, and Craspedochiton altavillensis is here extended to the Early Miocene. The distribution of Cryptoplax weinlandi is extended to the Middle Miocene (Serravallian. In total 35 chiton species (with 3.003 valves were identified in the Italian Miocene (including both parts of this series. Ten species became extinct at the end of the Miocene, six in the Pliocene, two in the Pleistocene, and 17 are extant. Of the extant species nine occur both in the Atlantic and Mediterranean, two exclusively in the Atlantic and six only in the Mediterranean. The number of species reported from the Torino Hill assemblages (Burdigalian? is increased from three listed by Sacco (1897 to nine. Thirty-four of the 35 species (excluding only Lepidopleurus benoisti occur in the Tortonian-Messinian Po Basin. Thirteen (37% of the species are also found in the Miocene Paratethys (Austria, Poland, Czech Republic, Hungary, Romania and Ukraine, which

  19. Permanent groundwater storage in basaltic dyke fractures and termite mound viability

    Science.gov (United States)

    Mège, Daniel; Rango, Tewodros

    2010-04-01

    Many basaltic dykes of the Ethiopian flood basalt province are observed in the northwestern Ethiopian lowlands. In this area, the termites preferentially build their epigeous mounds on the top of dolerite dykes. The relationship between termite mounds and dykes is investigated from the analysis of their distribution along one of these dykes, of thickness 2-5 m, that we could follow over 2000 m. Termite mounds are periodically spaced (mean distance 63 m, R2 = 0.995), and located exclusively where the topographic relief of the dyke is not more than 2 m above the surrounding area. From these observations and from the geological context, a hydrological circuit model is proposed in which (1) dykes are preferential conduits for groundwater drainage during the rainy season due to pervasive jointing, (2) during the dry season, the portion of the dyke forming a local topographic relief area dries up more quickly than the surroundings, the elevation difference between the dyke summit and the surroundings being a factor restricting termite mound development. For dyke topographic relief >2 m, drying is an obstacle for maintaining the appropriate humidity for the termite colony life. Periodic termite mound spacing is unlikely to be related to dyke or other geological properties. It is more likely related to termite population behaviour, perhaps to clay shortage, which restricts termite population growth by limiting the quantity of building material available for mound extension, and triggers exploration for a new colonization site that will be located along the dyke at a distance from the former colony that may be controlled by the extent of the zone covered by its trail pheromones. This work brings out the importance of dykes in channelling and storing groundwater in semiarid regions, and shows that dykes can store groundwater permanently in such settings even though the dry season is half the year long. It contributes also to shedding light on water supply conditions

  20. Miocene shoshonite volcanism in Sardinia: Implications for magma sources and geodynamic evolution of the central-western Mediterranean

    Science.gov (United States)

    Beccaluva, Luigi; Bianchini, Gianluca; Mameli, Paola; Natali, Claudio

    2013-11-01

    In this paper we document the existence of a Miocene shoshonite (SHO) volcanism in Northern Sardinia (Anglona). This occurrence completes the spectrum of orogenic magmas related to the subduction process which developed from the Eocene along the Palaeo-European continental margin, in concert with the opening of the Ligurian-Balearic back-arc basin and southeastward drift/rotation of the Sardinia-Corsica continental block. K-Ar ages show that the oldest volcanics of the area are calcalkaline (CA) basalts and andesites (~ 21 Ma), overlain by 19.7-18.4 Ma-old more potassic products such as high-potassium calcalkaline (HK-CA) and SHO lavas. CA, HK-CA and SHO suites include basalts and differentiated lavas of andesite and latite composition, respectively, that (according to the PELE software modelling) represent ~ 40-45% residual liquid fraction after shallow fractional crystallization. Application of the "Arc Magma Simulator" software suggests that the generation of primary melts of the distinct suites may occur at similar degrees of partial melting (5-8%) and melting pressures (2-2.2 GPa, ~ 60-70 km depth) in the mantle wedge. By contrast, the potassic character of parental melts of CA, HK-CA and SHO suites is controlled by 1) the amount of subducted continental components (possibly terrigenous sediments) and 2) the pressure (depth) at which these metasomatic agents are released from the slab. Results suggest that the slab depth beneath the volcanic district increased from ~ 80-100 to 100-120 km for CA and SHO magmas, respectively. Accordingly, the evolution from CA to SHO magmatism in the same plumbing system could be related to slab deepening and increase of the subduction angle of ~ 5-10° in the time span of 2-3 Ma. This tectono-magmatic scenario conforms to the major anticlockwise rotation (~ 30°) event of the Sardinia block (between 20.5 and 18 Ma). This geodynamic evolution preludes the development of the volcanism in the Apennine-Tyrrhenian domains, where the

  1. Mitigating flood exposure

    Science.gov (United States)

    Shultz, James M; McLean, Andrew; Herberman Mash, Holly B; Rosen, Alexa; Kelly, Fiona; Solo-Gabriele, Helena M; Youngs Jr, Georgia A; Jensen, Jessica; Bernal, Oscar; Neria, Yuval

    2013-01-01

    Introduction. In 2011, following heavy winter snowfall, two cities bordering two rivers in North Dakota, USA faced major flood threats. Flooding was foreseeable and predictable although the extent of risk was uncertain. One community, Fargo, situated in a shallow river basin, successfully mitigated and prevented flooding. For the other community, Minot, located in a deep river valley, prevention was not possible and downtown businesses and one-quarter of the homes were inundated, in the city’s worst flood on record. We aimed at contrasting the respective hazards, vulnerabilities, stressors, psychological risk factors, psychosocial consequences, and disaster risk reduction strategies under conditions where flood prevention was, and was not, possible. Methods. We applied the “trauma signature analysis” (TSIG) approach to compare the hazard profiles, identify salient disaster stressors, document the key components of disaster risk reduction response, and examine indicators of community resilience. Results. Two demographically-comparable communities, Fargo and Minot, faced challenging river flood threats and exhibited effective coordination across community sectors. We examined the implementation of disaster risk reduction strategies in situations where coordinated citizen action was able to prevent disaster impact (hazard avoidance) compared to the more common scenario when unpreventable disaster strikes, causing destruction, harm, and distress. Across a range of indicators, it is clear that successful mitigation diminishes both physical and psychological impact, thereby reducing the trauma signature of the event. Conclusion. In contrast to experience of historic flooding in Minot, the city of Fargo succeeded in reducing the trauma signature by way of reducing risk through mitigation. PMID:28228985

  2. Application of Flood Nomograph for Flood Forecasting in Urban Areas

    Directory of Open Access Journals (Sweden)

    Eui Hoon Lee

    2018-01-01

    Full Text Available Imperviousness has increased due to urbanization, as has the frequency of extreme rainfall events by climate change. Various countermeasures, such as structural and nonstructural measures, are required to prepare for these effects. Flood forecasting is a representative nonstructural measure. Flood forecasting techniques have been developed for the prevention of repetitive flood damage in urban areas. It is difficult to apply some flood forecasting techniques using training processes because training needs to be applied at every usage. The other flood forecasting techniques that use rainfall data predicted by radar are not appropriate for small areas, such as single drainage basins. In this study, a new flood forecasting technique is suggested to reduce flood damage in urban areas. The flood nomograph consists of the first flooding nodes in rainfall runoff simulations with synthetic rainfall data at each duration. When selecting the first flooding node, the initial amount of synthetic rainfall is 1 mm, which increases in 1 mm increments until flooding occurs. The advantage of this flood forecasting technique is its simple application using real-time rainfall data. This technique can be used to prepare a preemptive response in the process of urban flood management.

  3. The Axum-Adwa basalt-trachyte complex: a late magmatic activity at the periphery of the Afar plume

    Science.gov (United States)

    Natali, C.; Beccaluva, L.; Bianchini, G.; Siena, F.

    2013-08-01

    The Axum-Adwa igneous complex consists of a basalt-trachyte (syenite) suite emplaced at the northern periphery of the Ethiopian plateau, after the paroxysmal eruption of the Oligocene (ca 30 Ma) continental flood basalts (CFB), which is related to the Afar plume activity. 40Ar/39Ar and K-Ar ages, carried out for the first time on felsic and basaltic rocks, constrain the magmatic age of the greater part of the complex around Axum to 19-15 Ma, whereas trachytic lavas from volcanic centres NE of Adwa are dated ca 27 Ma. The felsic compositions straddle the critical SiO2-saturation boundary, ranging from normative quartz trachyte lavas east of Adwa to normative (and modal) nepheline syenite subvolcanic domes (the obelisks stones of ancient axumites) around Axum. Petrogenetic modelling based on rock chemical data and phase equilibria calculations by PELE (Boudreau 1999) shows that low-pressure fractional crystallization processes, starting from mildly alkaline- and alkaline basalts comparable to those present in the complex, could generate SiO2-saturated trachytes and SiO2-undersaturated syenites, respectively, which correspond to residual liquid fractions of 17 and 10 %. The observed differentiation processes are consistent with the development of rifting events and formation of shallow magma chambers plausibly located between displaced (tilted) crustal blocks that favoured trapping of basaltic parental magmas and their fractionation to felsic differentiates. In syenitic domes, late- to post-magmatic processes are sometimes evidenced by secondary mineral associations (e.g. Bete Giorgis dome) which overprint the magmatic parageneses, and mainly induce additional nepheline and sodic pyroxene neo-crystallization. These metasomatic reactions were promoted by the circulation of Na-Cl-rich deuteric fluids (600-400 °C), as indicated by mineral and bulk rock chemical budgets as well as by δ18O analyses on mineral separates. The occurrence of this magmatism post-dating the

  4. Crowdsourcing detailed flood data

    Science.gov (United States)

    Walliman, Nicholas; Ogden, Ray; Amouzad*, Shahrzhad

    2015-04-01

    Over the last decade the average annual loss across the European Union due to flooding has been 4.5bn Euros, but increasingly intense rainfall, as well as population growth, urbanisation and the rising costs of asset replacements, may see this rise to 23bn Euros a year by 2050. Equally disturbing are the profound social costs to individuals, families and communities which in addition to loss of lives include: loss of livelihoods, decreased purchasing and production power, relocation and migration, adverse psychosocial effects, and hindrance of economic growth and development. Flood prediction, management and defence strategies rely on the availability of accurate information and flood modelling. Whilst automated data gathering (by measurement and satellite) of the extent of flooding is already advanced it is least reliable in urban and physically complex geographies where often the need for precise estimation is most acute. Crowdsourced data of actual flood events is a potentially critical component of this allowing improved accuracy in situations and identifying the effects of local landscape and topography where the height of a simple kerb, or discontinuity in a boundary wall can have profound importance. Mobile 'App' based data acquisition using crowdsourcing in critical areas can combine camera records with GPS positional data and time, as well as descriptive data relating to the event. This will automatically produce a dataset, managed in ArcView GIS, with the potential for follow up calls to get more information through structured scripts for each strand. Through this local residents can provide highly detailed information that can be reflected in sophisticated flood protection models and be core to framing urban resilience strategies and optimising the effectiveness of investment. This paper will describe this pioneering approach that will develop flood event data in support of systems that will advance existing approaches such as developed in the in the UK

  5. Experimental Melting Study of Basalt-Peridotite Hybrid Source: Melting model of Hawaiian plume

    Science.gov (United States)

    Takahashi, E.; Gao, S.

    2015-12-01

    Eclogite component entrained in ascending plume is considered to be essentially important in producing flood basalts (e.g., Columbia River basalt, Takahashi et al., 1998 EPSL), alkalic OIBs (e.g., Kogiso et al.,2003), ferro-picrites (Tuff et al.,2005) and Hawaiian shield lavas (e.g., Hauri, 1996; Takahashi & Nakajima, 2002, Sobolev et al.,2005). Size of the entrained eclogite, which controls the reaction rates with ambient peridotite, however, is very difficult to constrain using geophysical observation. Among Hawaiian shield volcanoes, Koolau is the most enriched end-member in eclogite component (Frey et al, 1994). Reconstruction of Koolau volcano based on submarine study on Nuuanu landslide (AGU Monograph vol.128, 2002, Takahashi Garcia Lipman eds.) revealed that silica-rich tholeiite appeared only at the last stage (Makapuu stage) of Koolau volcano. Chemical compositions of lavas as well as isotopes change abruptly and coherently across a horizon (Shinozaki et al. and Tanaka et al. ibid.). Based on these observation, Takahashi & Nakajima (2002 ibid) proposed that the Makapuu stage lava in Koolau volcano was supplied from a single large eclogite block. In order to study melting process in Hawaiian plume, high-pressure melting experiments were carried out under dry and hydrous conditions with layered eclogite/peridotite starting materials. Detail of our experiments will be given by Gao et al (2015 AGU). Combined previous field observation with new set of experiments, we propose that variation in SiO2 among Hawaiian tholeiites represent varying degree of wall-rock interaction between eclogite and ambient peridotite. Makapuu stage lavas in Koolau volcano represents eclogite partial melts formed at ~3 GPa with various amount of xenocrystic olivines derived from Pacific plate. In other words, we propose that "primary magma" in the melting column of Hawaiian plume ranges from basaltic andesite to ferro-picrite depending on the lithology of the source. Solidus of

  6. Corrosion phase formation on container alloys in basalt repository environments

    International Nuclear Information System (INIS)

    Johnston, R.G.; Anantatmula, R.P.; Lutton, J.M.; Rivera, C.L.

    1986-01-01

    The Basalt Waste Isolation Project is evaluating the suitability of basalt in southeastern Washington State as a possible location for a nuclear waste repository. The performance of the waste package, which includes the waste form, container, and surrounding packing material, will be affected by the stability of container alloys in the repository environment. Primary corrosion phases and altered packing material containing metals leached from the container may also influence subsequent reactions between the waste form and repository environment. Copper- and iron-based alloys were tested at 50 0 to 300 0 C in an air/steam environment and in pressure vessels in ground-water-saturated basalt-bentonite packing material. Reaction phases formed on the alloys were identified and corrosion rates were measured. Changes in adhering packing material were also evaluated. The observed reactions and their possible effects on container alloy durability in the repository are discussed

  7. Regional basalt hydrology of the Columbia Plateau in Washington

    International Nuclear Information System (INIS)

    Tanaka, H.; Barrett, G.; Wildrick, L.

    1979-10-01

    This study is part of the Basalt Waste Isolation Project, operated for the US Department of Energy by Rockwell Hanford Operations. The overall purpose of the study is to assess locations within the Columbia River Basalt Group beneath the Hanford Site in south-central Washington suitable for a geologic repository for radioactive waste. This hydrologic study was made to describe the hydrologic characteristics of the basalt units of the Columbia Plateau. This was done by comprehensive data compilation, data interpretation and analysis. Data are presented in the form of maps and tables suitable as input information about the regional hydrology for possible future analysis by computer models. The report includes: an introduction; basic data; interpretation which covers stratigraphic trend surface, water levels, transmissivity and storage of aquifers, recharge, discharge, flow, subbasins, cross sections, references and appendix of record of wells

  8. Basalt woven fiber reinforced vinylester composites: Flexural and electrical properties

    International Nuclear Information System (INIS)

    Carmisciano, Salvatore; Rosa, Igor Maria De; Sarasini, Fabrizio; Tamburrano, Alessio; Valente, Marco

    2011-01-01

    A preliminary comparative study of basalt and E-glass woven fabric reinforced composites was performed. The fabrics were characterized by the same weave pattern and the laminates tested by the same fiber volume fraction. Results of the flexural and interlaminar characterization are reported. Basalt fiber composites showed higher flexural modulus and apparent interlaminar shear strength (ILSS) in comparison with E-glass ones but also a lower flexural strength and similar electrical properties. With this fiber volume fraction, scanning electron microscopy (SEM) analysis of the fractured surfaces enabled a better understanding both of the failure modes involved and of points of concern. Nevertheless, the results of this study seem promising in view of a full exploitation of basalt fibers as reinforcement in polymer matrix composites (PMCs).

  9. Corrosion and tribological properties of basalt fiber reinforced composite materials

    Science.gov (United States)

    Ha, Jin Cheol; Kim, Yun-Hae; Lee, Myeong-Hoon; Moon, Kyung-Man; Park, Se-Ho

    2015-03-01

    This experiment has examined the corrosion and tribological properties of basalt fiber reinforced composite materials. There were slight changes of weight after the occurring of corrosion based on time and H2SO4 concentration, but in general, the weight increased. It is assumed that this happens due to the basalt fiber precipitate. Prior to the corrosion, friction-wear behavior showed irregular patterns compared to metallic materials, and when it was compared with the behavior after the corrosion, the coefficient of friction was 2 to 3 times greater. The coefficient of friction of all test specimen ranged from 0.1 to 0.2. Such a result has proven that the basalt fiber, similar to the resin rubber, shows regular patterns regardless of time and H2SO4 concentration because of the space made between resins and reinforced materials.

  10. Floods in Colorado

    Science.gov (United States)

    Follansbee, Robert; Sawyer, Leon R.

    1948-01-01

    The first records of floods in Colorado antedated the settlement of the State by about 30 years. These were records of floods on the Arkansas and Republican Rivers in 1826. Other floods noted by traders, hunters and emigrants, some of whom were on their way to the Far West, occurred in 1844 on the Arkansas River, and by inference on the South Platte River. Other early floods were those on the Purgatoire, the Lower Arkansas, and the San Juan Rivers about 1859. The most serious flood since settlement began was that on the Arkansas River during June 1921, which caused the loss of about 100 lives and an estimated property loss of $19,000,000. Many floods of lesser magnitude have occurred, and some of these have caused loss of life and very considerable property damage. Topography is the chief factor in determining the location of storms and resulting floods. These occur most frequently on the eastern slope of the Front Range. In the mountains farther west precipitation is insufficient to cause floods except during periods of melting snow, in June. In the southwestern part of the State, where precipitation during periods of melting snow is insufficient to cause floods, the severest floods yet experienced resulted from heavy rains in September 1909 and October 1911. In the eastern foothills region, usually below an altitude of about 7,500 feet and extending for a distance of about 50 miles east of the mountains, is a zone subject to rainfalls of great intensity known as cloudbursts. These cloudbursts are of short duration and are confined to very small areas. At times the intensity is so great as to make breathing difficult for those exposed to a storm. The areas of intense rainfall are so small that Weather Bureau precipitation stations have not been located in them. Local residents, being cloudburst conscious, frequently measure the rainfall in receptacles in their yards, and such records constitute the only source of information regarding the intensity. A flood

  11. Technetium and neptunium reactions in basalt/groundwater systems

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.

    1985-01-01

    Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/l Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to 10 -6 mol/l and 8 x 10 -7 mol/l under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 references, 6 figures

  12. Technetium and neptunium reactions in basalt/groundwater systems

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.; Florida State Univ., Tallahassee)

    1984-01-01

    Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/L Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to approx. 10 -6 mol/L and 8 x 10 -7 mol/L under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 refs., 6 tabs

  13. Basalt fiber reinforced polymer composites: Processing and properties

    Science.gov (United States)

    Liu, Qiang

    A high efficiency rig was designed and built for in-plane permeability measurement of fabric materials. A new data derivation procedure to acquire the flow fluid pattern in the experiment was developed. The measurement results of the in-plane permeability for basalt twill 31 fabric material showed that a high correlation exists between the two principal permeability values for this fabric at 35% fiber volume fraction. This may be the most important scientific contribution made in this thesis. The results from radial measurements corresponded quite well with those from Unidirectional (UD) measurements, which is a well-established technique. No significant differences in mechanical properties were found between basalt fabric reinforced polymer composites and glass composites reinforced by a fabric of similar weave pattern. Aging results indicate that the interfacial region in basalt composites may be more vulnerable to environmental damage than that in glass composites. However, the basalt/epoxy interface may have been more durable than the glass/epoxy interface in tension-tension fatigue because the basalt composites have significantly longer fatigue life. In this thesis, chapter I reviews the literature on fiber reinforced polymer composites, with concentration on permeability measurement, mechanical properties and durability. Chapter II discusses the design of the new rig for in-plane permeability measurement, the new derivation procedure for monitoring of the fluid flow pattern, and the permeability measurement results. Chapter III compares the mechanical properties and durability between basalt fiber and glass fiber reinforced polymer composites. Lastly, chapter IV gives some suggestions and recommendations for future work.

  14. Distribution and stratigraphy of basaltic units in Maria Tranquillitatis and Fecunditatis: A Clementine perspective

    Science.gov (United States)

    Rajmon, D.; Spudis, P.

    2004-01-01

    Maria Tranquillitatis and Fecunditatis have been mapped based on Clementine image mosaics and derived iron and titanium maps. Impact craters served as stratigraphic probes enabling better delineation of compositionally different basaltic units, determining the distribution of subsurface basalts, and providing estimates of total basalt thickness and the thickness of the surface units. Collected data indicate that volcanism in these maria started with the eruption of low-Ti basalts and evolved toward medium- and high-Ti basalts. Some of the high-Ti basalts in Mare Tranquillitatis began erupting early and were contemporaneous with the low- and medium-Ti basalts; these units form the oldest units exposed on the mare surface. Mare Tranquillitatis is mostly covered with high- Ti basalts. In Mare Fecunditatis, the volume of erupting basalts clearly decreased as the Ti content increased, and the high-Ti basalts occur as a few patches on the mare surface. The basalt in both maria is on the order of several hundred meters thick and locally may be as thick as 1600 m. The new basalt thickness estimates generally fall within the range set by earlier studies, although locally differ. The medium- to high-Ti basalts exposed at the surfaces of both maria are meters to tens of meters thick.

  15. Hydrothermal waste package interactions with methane-containing basalt groundwater

    International Nuclear Information System (INIS)

    McGrail, B.P.

    1984-01-01

    Hydrothermal waste package interaction tests were conducted with a mixture of crushed glass, basalt, and steel in methane-containing synthetic basalt groundwater. In the absence of gamma radiolysis, methane was found to have little influence on the corrosion behavior of the waste package constituents. Under gamma radiolysis, methane was found to significantly lower the solution oxidation potential when compared to identical tests without methane. In addition, colloidal hydrocarbon polymers that have been produced under the irradiation conditions of these experiments were not formed. The presence of the waste package constituents apparently inhibited the formation of the polymers. However, the mechanism which prevented their formation was not determined

  16. Friction Joint Between Basalt-Reinforced Composite and Aluminum

    DEFF Research Database (Denmark)

    Costache, Andrei; Glejbøl, Kristian; Sivebæk, Ion Marius

    2015-01-01

    The purpose of this study was to anchor basalt-reinforced polymers in an aluminum grip using dry friction. Dry friction clamping is considered the optimal solution for post-mounting of load-bearing terminations on composite structures. A new test method is presented for characterizing the frictio......The purpose of this study was to anchor basalt-reinforced polymers in an aluminum grip using dry friction. Dry friction clamping is considered the optimal solution for post-mounting of load-bearing terminations on composite structures. A new test method is presented for characterizing...

  17. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  18. Probabilistic flood extent estimates from social media flood observations

    NARCIS (Netherlands)

    Brouwer, Tom; Eilander, Dirk; Van Loenen, Arnejan; Booij, Martijn J.; Wijnberg, Kathelijne M.; Verkade, Jan S.; Wagemaker, Jurjen

    2017-01-01

    The increasing number and severity of floods, driven by phenomena such as urbanization, deforestation, subsidence and climate change, create a growing need for accurate and timely flood maps. In this paper we present and evaluate a method to create deterministic and probabilistic flood maps from

  19. Probabilistic flood extent estimates from social media flood observations

    NARCIS (Netherlands)

    Brouwer, Tom; Eilander, Dirk; Van Loenen, Arnejan; Booij, Martijn J.; Wijnberg, Kathelijne M.; Verkade, Jan S.; Wagemaker, Jurjen

    2017-01-01

    The increasing number and severity of floods, driven by phenomena such as urbanization, deforestation, subsidence and climate change, creates a growing need for accurate and timely flood maps. This research focussed on creating flood maps using user generated content from Twitter. Twitter data has

  20. Mapping flood hazards under uncertainty through probabilistic flood inundation maps

    Science.gov (United States)

    Stephens, T.; Bledsoe, B. P.; Miller, A. J.; Lee, G.

    2017-12-01

    Changing precipitation, rapid urbanization, and population growth interact to create unprecedented challenges for flood mitigation and management. Standard methods for estimating risk from flood inundation maps generally involve simulations of floodplain hydraulics for an established regulatory discharge of specified frequency. Hydraulic model results are then geospatially mapped and depicted as a discrete boundary of flood extents and a binary representation of the probability of inundation (in or out) that is assumed constant over a project's lifetime. Consequently, existing methods utilized to define flood hazards and assess risk management are hindered by deterministic approaches that assume stationarity in a nonstationary world, failing to account for spatio-temporal variability of climate and land use as they translate to hydraulic models. This presentation outlines novel techniques for portraying flood hazards and the results of multiple flood inundation maps spanning hydroclimatic regions. Flood inundation maps generated through modeling of floodplain hydraulics are probabilistic reflecting uncertainty quantified through Monte-Carlo analyses of model inputs and parameters under current and future scenarios. The likelihood of inundation and range of variability in flood extents resulting from Monte-Carlo simulations are then compared with deterministic evaluations of flood hazards from current regulatory flood hazard maps. By facilitating alternative approaches of portraying flood hazards, the novel techniques described in this presentation can contribute to a shifting paradigm in flood management that acknowledges the inherent uncertainty in model estimates and the nonstationary behavior of land use and climate.

  1. Flood Risk Management In Europe: European flood regulation

    NARCIS (Netherlands)

    Hegger, D.L.T.; Bakker, M.H.; Green, C.; Driessen, Peter; Delvaux, B.; Rijswick, H.F.M.W. van; Suykens, C.; Beyers, J-C.; Deketelaere, K.; Doorn-Hoekveld, W. van; Dieperink, C.

    2013-01-01

    In Europe, water management is moving from flood defense to a risk management approach, which takes both the probability and the potential consequences of flooding into account. In this report, we will look at Directives and (non-)EU- initiatives in place to deal with flood risk in Europe indirectly

  2. Exploitation of Documented Historical Floods for Achieving Better Flood Defense

    Directory of Open Access Journals (Sweden)

    Slobodan Kolaković

    2016-01-01

    Full Text Available Establishing Base Flood Elevation for a stream network corresponding to a big catchment is feasible by interdisciplinary approach, involving stochastic hydrology, river hydraulics, and computer aided simulations. A numerical model calibrated by historical floods has been exploited in this study. The short presentation of the catchment of the Tisza River in this paper is followed by the overview of historical floods which hit the region in the documented period of 130 years. Several well documented historical floods provided opportunity for the calibration of the chosen numerical model. Once established, the model could be used for investigation of different extreme flood scenarios and to establish the Base Flood Elevation. The calibration has shown that the coefficient of friction in case of the Tisza River is dependent both on the actual water level and on the preceding flood events. The effect of flood plain maintenance as well as the activation of six potential detention ponds on flood mitigation has been examined. Furthermore, the expected maximum water levels have also been determined for the case if the ever observed biggest 1888 flood hit the region again. The investigated cases of flood superposition highlighted the impact of tributary Maros on flood mitigation along the Tisza River.

  3. Improving Global Flood Forecasting using Satellite Detected Flood Extent

    NARCIS (Netherlands)

    Revilla Romero, B.

    2016-01-01

    Flooding is a natural global phenomenon but in many cases is exacerbated by human activity. Although flooding generally affects humans in a negative way, bringing death, suffering, and economic impacts, it also has potentially beneficial effects. Early flood warning and forecasting systems, as well

  4. Bed-material entrainment potential, Roaring Fork River at Basalt, Colorado

    Science.gov (United States)

    Elliott, John G.

    2002-01-01

    The Roaring Fork River at Basalt, Colorado, has a frequently mobile streambed composed of gravel, cobbles, and boulders. Recent urban and highway development on the flood plain, earlier attempts to realign and confine the channel, and flow obstructions such as bridge openings and piers have altered the hydrology, hydraulics, sediment transport, and sediment deposition areas of the Roaring Fork. Entrainment and deposition of coarse sediment on the streambed and in large alluvial bars have reduced the flood-conveying capacity of the river. Previous engineering studies have identified flood-prone areas and hazards related to inundation and high streamflow velocity, but those studies have not evaluated the potential response of the channel to discharges that entrain the coarse streambed. This study builds upon the results of earlier flood studies and identifies some potential areas of concern associated with bed-material entrainment. Cross-section surveys and simulated water-surface elevations from a previously run HEC?RAS model were used to calculate the boundary shear stress on the mean streambed, in the thalweg, and on the tops of adjacent alluvial bars for four reference streamflows. Sediment-size characteristics were determined for surficial material on the streambed, on large alluvial bars, and on a streambank. The median particle size (d50) for the streambed samples was 165 millimeters and for the alluvial bars and bank samples was 107 millimeters. Shear stresses generated by the 10-, 50-, and 100-year floods, and by a more common flow that just inundated most of the alluvial bars in the study reach were calculated at 14 of the cross sections used in the Roaring Fork River HEC?RAS model. The Shields equation was used with a Shields parameter of 0.030 to estimate the critical shear stress for entrainment of the median sediment particle size on the mean streambed, in the thalweg, and on adjacent alluvial bar surfaces at the 14 cross sections. Sediment

  5. The Global Flood Model

    Science.gov (United States)

    Williams, P.; Huddelston, M.; Michel, G.; Thompson, S.; Heynert, K.; Pickering, C.; Abbott Donnelly, I.; Fewtrell, T.; Galy, H.; Sperna Weiland, F.; Winsemius, H.; Weerts, A.; Nixon, S.; Davies, P.; Schiferli, D.

    2012-04-01

    Recently, a Global Flood Model (GFM) initiative has been proposed by Willis, UK Met Office, Esri, Deltares and IBM. The idea is to create a global community platform that enables better understanding of the complexities of flood risk assessment to better support the decisions, education and communication needed to mitigate flood risk. The GFM will provide tools for assessing the risk of floods, for devising mitigation strategies such as land-use changes and infrastructure improvements, and for enabling effective pre- and post-flood event response. The GFM combines humanitarian and commercial motives. It will benefit: - The public, seeking to preserve personal safety and property; - State and local governments, seeking to safeguard economic activity, and improve resilience; - NGOs, similarly seeking to respond proactively to flood events; - The insurance sector, seeking to understand and price flood risk; - Large corporations, seeking to protect global operations and supply chains. The GFM is an integrated and transparent set of modules, each composed of models and data. For each module, there are two core elements: a live "reference version" (a worked example) and a framework of specifications, which will allow development of alternative versions. In the future, users will be able to work with the reference version or substitute their own models and data. If these meet the specification for the relevant module, they will interoperate with the rest of the GFM. Some "crowd-sourced" modules could even be accredited and published to the wider GFM community. Our intent is to build on existing public, private and academic work, improve local adoption, and stimulate the development of multiple - but compatible - alternatives, so strengthening mankind's ability to manage flood impacts. The GFM is being developed and managed by a non-profit organization created for the purpose. The business model will be inspired from open source software (eg Linux): - for non-profit usage

  6. Camp Marmal Flood Study

    Science.gov (United States)

    2012-03-01

    was simulated by means of a broad - crested weir built into the topography of the mesh. There is 0.5 m of freeboard and the width of the weir is 30 m...ER D C/ CH L TR -1 2- 5 Camp Marmal Flood Study Co as ta l a nd H yd ra ul ic s La bo ra to ry Jeremy A. Sharp , Steve H. Scott...Camp Marmal Flood Study Jeremy A. Sharp , Steve H. Scott, Mark R. Jourdan, and Gaurav Savant Coastal and Hydraulics Laboratory U.S. Army Engineer

  7. Late Miocene radiolarian biostratigraphy and paleoceanography of Sawai Bay formation, Neill Island, Andamans, India

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.; Srinivasan, M.S.

    Late Miocene radiolarian zones are encountered from mudstone strata of Sawai Bay Formation, Neill Island, Andamans. Percentage data of forty-five coarser taxonomic groups of radiolarians were subjected to Q-mode cluster analysis. Based...

  8. The microfauna assemblages as indicators of paleoenvironmental changes in the Miocene fluvial- lacustrine cycles (NE Duero Basin, Spain

    Directory of Open Access Journals (Sweden)

    A. Herrero-Hernández

    2016-11-01

    Full Text Available The siliclastic and carbonate deposits are interbedded in the Villadiego area (Miocene, NE Duero Basin. They have been subdivided into two high-rank depositional sequences: DDS and CDS. The sedimentary analysis of these units and the study of the microfauna content, mainly ostracods, led to the identification of lacustrine-fluvial interaction systems. The sedimentary characteristics reveal the existence of fluvial systems of gravel, flood plains and lacustrine systems that were interconnected and intimately related in north-south direction. In the sedimentological analysis, thirteen types of fluvial and lacustrine lithofacies and six genetic facies associations were recognized. The top of DDS is the result of lake level risings. The CDS shows a deepening-shallowing cycle. The ostracod micropaleontological analysis of the sediments have been studied, with the aim of reconstructing the palaeoenvironmental evolution of this area. These microfauna assemblages integrated with the analysis of the sedimentary facies allowed to conclude the existence of lakes with a water-bearing level of few tens of meters. A change in the chemical conditions of the waters, which evolved from oligohaline and carbonated to mesohaline and sulphated is concluded.

  9. FEMA DFIRM Base Flood Elevations

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Base Flood Elevation (BFE) table is required for any digital data where BFE lines will be shown on the corresponding Flood Insurance Rate Map (FIRM). Normally,...

  10. 2013 FEMA Flood Hazard Boundaries

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  11. FEMA DFIRM Flood Hazard Areas

    Data.gov (United States)

    Minnesota Department of Natural Resources — FEMA flood hazard delineations are used by the Federal Emergency Management Agency (FEMA) to designate the Special Flood Hazard Area (SFHA) and for insurance rating...

  12. Base Flood Elevation (BFE) Lines

    Data.gov (United States)

    Department of Homeland Security — The Base Flood Elevation (BFE) table is required for any digital data where BFE lines will be shown on the corresponding Flood Insurance Rate Map (FIRM). Normally if...

  13. National Flood Hazard Layer (NFHL)

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The National Flood Hazard Layer (NFHL) is a compilation of GIS data that comprises a nationwide digital Flood Insurance Rate Map. The GIS data and services are...

  14. FEMA 100 year Flood Data

    Data.gov (United States)

    California Natural Resource Agency — The Q3 Flood Data product is a digital representation of certain features of FEMA's Flood Insurance Rate Map (FIRM) product, intended for use with desktop mapping...

  15. 2013 FEMA Flood Control Structures

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  16. FEMA Q3 Flood Data

    Data.gov (United States)

    Kansas Data Access and Support Center — The Q3 Flood Data are derived from the Flood Insurance Rate Maps (FIRMS) published by the Federal Emergency Management Agency (FEMA). The file is georeferenced to...

  17. Preliminary feasibility study on storage of radioactive wastes in Columbia River basalts. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    ,

    1976-11-01

    Volume II comprises four appendices: analytical data and sample locations for basalt flow type localities; Analytical data and sample locations for measured field sections in Yakima basalts; core hole lithology and analytical data; and geophysical logs. (LK)

  18. Mobilization of manganese by basalt associated Mn(II)-oxidizing bacteria from the Indian Ridge System

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; Mourya, B.S.; Krishnamurthi, S.; Meena, R.M.; LokaBharathi, P.A.

    The Indian Ridge System basalt bearing Mn-oxide coatings had todorokite as the major and birnesite as the minor mineral. We posit that microorganisms associated with these basalts participate in the oxidation of Mn and contribute to mineral...

  19. Petrographical indicators of petrogenesis: Examples from Central Indian Ocean Basin basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Mislankar, P.G.; Iyer, S.D.

    Petrographical features of the Central Indian Basin (CIOB) basalts were studied to understand their genetic significance. The fresh basaltic pillows show three textural zones from the top glassy (zone A) through the intermediate (zone B...

  20. Use of solar power for the production of basalt-based mineral fibers

    International Nuclear Information System (INIS)

    Gulamova, D. D.; Shevchenko, V. P.; Tokunov, S. G.; Kim, R. B.

    2012-01-01

    The possibility of obtaining basalt mineral fibers using concentrating solar power and melt-quench technique is shown. The microstructure and physicochemical properties of basalt fibers are analyzed. (author)

  1. Multivariate pluvial flood damage models

    International Nuclear Information System (INIS)

    Van Ootegem, Luc; Verhofstadt, Elsy; Van Herck, Kristine; Creten, Tom

    2015-01-01

    Depth–damage-functions, relating the monetary flood damage to the depth of the inundation, are commonly used in the case of fluvial floods (floods caused by a river overflowing). We construct four multivariate damage models for pluvial floods (caused by extreme rainfall) by differentiating on the one hand between ground floor floods and basement floods and on the other hand between damage to residential buildings and damage to housing contents. We do not only take into account the effect of flood-depth on damage, but also incorporate the effects of non-hazard indicators (building characteristics, behavioural indicators and socio-economic variables). By using a Tobit-estimation technique on identified victims of pluvial floods in Flanders (Belgium), we take into account the effect of cases of reported zero damage. Our results show that the flood depth is an important predictor of damage, but with a diverging impact between ground floor floods and basement floods. Also non-hazard indicators are important. For example being aware of the risk just before the water enters the building reduces content damage considerably, underlining the importance of warning systems and policy in this case of pluvial floods. - Highlights: • Prediction of damage of pluvial floods using also non-hazard information • We include ‘no damage cases’ using a Tobit model. • The damage of flood depth is stronger for ground floor than for basement floods. • Non-hazard indicators are especially important for content damage. • Potential gain of policies that increase awareness of flood risks

  2. Multivariate pluvial flood damage models

    Energy Technology Data Exchange (ETDEWEB)

    Van Ootegem, Luc [HIVA — University of Louvain (Belgium); SHERPPA — Ghent University (Belgium); Verhofstadt, Elsy [SHERPPA — Ghent University (Belgium); Van Herck, Kristine; Creten, Tom [HIVA — University of Louvain (Belgium)

    2015-09-15

    Depth–damage-functions, relating the monetary flood damage to the depth of the inundation, are commonly used in the case of fluvial floods (floods caused by a river overflowing). We construct four multivariate damage models for pluvial floods (caused by extreme rainfall) by differentiating on the one hand between ground floor floods and basement floods and on the other hand between damage to residential buildings and damage to housing contents. We do not only take into account the effect of flood-depth on damage, but also incorporate the effects of non-hazard indicators (building characteristics, behavioural indicators and socio-economic variables). By using a Tobit-estimation technique on identified victims of pluvial floods in Flanders (Belgium), we take into account the effect of cases of reported zero damage. Our results show that the flood depth is an important predictor of damage, but with a diverging impact between ground floor floods and basement floods. Also non-hazard indicators are important. For example being aware of the risk just before the water enters the building reduces content damage considerably, underlining the importance of warning systems and policy in this case of pluvial floods. - Highlights: • Prediction of damage of pluvial floods using also non-hazard information • We include ‘no damage cases’ using a Tobit model. • The damage of flood depth is stronger for ground floor than for basement floods. • Non-hazard indicators are especially important for content damage. • Potential gain of policies that increase awareness of flood risks.

  3. Floods in a changing climate

    Science.gov (United States)

    Theresa K. Andersen; Marshall J. Shepherd

    2013-01-01

    Atmospheric warming and associated hydrological changes have implications for regional flood intensity and frequency. Climate models and hydrological models have the ability to integrate various contributing factors and assess potential changes to hydrology at global to local scales through the century. This survey of floods in a changing climate reviews flood...

  4. Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation

    OpenAIRE

    Choi, Jeong-Il; Lee, Bang

    2015-01-01

    The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber?s suitability as a reinforcing fiber. Single fiber pullout tests were performed and then th...

  5. Application of carbon isotope stratigraphy to late miocene shallow marine sediments, new zealand.

    Science.gov (United States)

    Loutit, T S; Kennett, J P

    1979-06-15

    A distinct (0.5 per mil) carbon-13/carbon-12 isotopic shift in the light direction has been identified in a shallow marine sedimentary sequence of Late Miocene age at Blind River, New Zealand, and correlated with a similar shift in Late Miocene Deep Sea Drilling Project sequences throughout the Indo-Pacific. A dated piston core provides an age for the shift of 6.2 +/- 0.1 million years. Correlations based on the carbon isotopic change require a revision of the previously established magnetostratigraphy at Blind River. The carbon shift at Blind River occurs between 6.2 and 6.3 +/- 0.1 million years before present. A new chronology provides an age for the evolutionary first appearance datum of Globorotalia conomiozea at 6.1 +/- 0.1 million years, the beginning of a distinct latest Miocene cooling event associated with the Kapitean stage at 6.2 +/- 0.1 million years, and the beginning of a distinct shallowing of water depths at 6.1 +/- 0.1 million years. The Miocene-Pliocene boundary as recognized in New Zealand is now dated at 5.3 +/- 0.1 million years. Extension of carbon isotope stratigraphy to other shallow Late Miocene sequences should provide an important datum for international correlation of Late Miocene shallow and deep marine sequences.

  6. Response of deep-sea benthic foraminifera to Miocene paleoclimatic events, DSDP site 289

    International Nuclear Information System (INIS)

    Woodruff, F.; Douglas, R.G.

    1981-01-01

    Changes in the Miocene deep-sea benthic foraminifera at DSDP Site 289 closely correlate to the climatically induced variations in deep and bottom waters in the Pacific Ocean. In early Miocene time, oxygen and carbon isotopes indicate that bottom waters were relatively warm and poorly oxygenated. Benthic foraminiferal assemblages are characterized by various species inherited from the Oligocene. Expansion of the Antarctic icecap in the early middle Miocene, 14-16 m.y. ago, increased oxygen isotope values, produced cold, more oxygenated bottom waters and lead to a turnover in the benthic foraminifera. An Oligocene-early Miocene assemblage was replaced by a cibicidoid-dominated assemblage. Some species became extinct and benthic faunas became more bathymetrically restricted with the increased stratification of deep waters in the ocean. In mid-Miocene time, Epistominella exigua and E. umbonifera, indicative of young, oxygenated bottom waters, are relatively common at DSDP Site 289. Further glacial expansion 5-9 m.y. ago lowered sealevel, increased oceanic upwelling and associated biological productivity and intensified the oxygen minima. Abundant hispid and costate uvigerines become a dominant faunal element at shallow depths above 2500 m as E. umbonifera becomes common to abundant below 2500 m. By late Miocene time, benthic faunas similar in species composition and proportion to modern faunas on the Ontong-Java plateau, had become established. (Auth.)

  7. Flame-resistant pure and hybrid woven fabrics from basalt

    Science.gov (United States)

    Jamshaid, H.; Mishra, R.; Militky, J.

    2017-10-01

    This work has been formulated to investigate the burning behavior of different type of fabrics. The main concentration is to see how long the fabric resists after it catches the fire and the propagation of fire can be reduced by using flame resistant fiber i.e basalt. Basalt fiber is an environmental friendly material with low input, high output, low energy consumption and less emission. The goal of present investigations is to show the dependence of fabric flammability on its structure parameters i.e weave type, blend type etc. Fabric weaves have strong effect on flammability properties. Plain weave has the lowest burning rate as the density of the plain weave fabric is more and the structure is tight which gives less chances of flame passing through the fabric. Thermal stability is evaluated with TGA of all hybrid and nonhybrid fabrics and compared. The thermal stability of the basalt fiber is excellent. When comparing thermal analysis curves for hybrid samples it demonstrates that thermal stability of the samples containing basalt is much higher than the non- hybrid samples. Percentage weight loss is less in hybrid samples as compared to non-hybrid samples. The effectiveness of hybridization on samples may be indicated by substantial lowering of the decomposition mass. Correlation was made between flammability with the infrared radiations (IR)

  8. Nuclear waste package materials testing report: basaltic and tuffaceous environments

    International Nuclear Information System (INIS)

    Bradley, D.J.; Coles, D.G.; Hodges, F.N.; McVay, G.L.; Westerman, R.E.

    1983-03-01

    The disposal of high-level nuclear wastes in underground repositories in the continental United States requires the development of a waste package that will contain radionuclides for a time period commensurate with performance criteria, which may be up to 1000 years. This report addresses materials testing in support of a waste package for a basalt (Hanford, Washington) or a tuff (Nevada Test Site) repository. The materials investigated in this testing effort were: sodium and calcium bentonites and mixtures with sand or basalt as a backfill; iron and titanium-based alloys as structural barriers; and borosilicate waste glass PNL 76-68 as a waste form. The testing also incorporated site-specific rock media and ground waters: Reference Umtanum Entablature-1 basalt and reference basalt ground water, Bullfrog tuff and NTS J-13 well water. The results of the testing are discussed in four major categories: Backfill Materials: emphasizing water migration, radionuclide migration, physical property and long-term stability studies. Structural Barriers: emphasizing uniform corrosion, irradiation-corrosion, and environmental-mechanical testing. Waste Form Release Characteristics: emphasizing ground water, sample surface area/solution volume ratio, and gamma radiolysis effects. Component Compatibility: emphasizing solution/rock, glass/rock, glass/structural barrier, and glass/backfill interaction tests. This area also includes sensitivity testing to determine primary parameters to be studied, and the results of systems tests where more than two waste package components were combined during a single test

  9. Genetic aspects of basalts from the Carlsberg Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    of the CR rocks are sparse. The bulk chemical, mineral chemical and ore mineralization aspects of the dredged basalts from a segment of the CR (at 3°37¢N, 64°57¢E) are synthesized to indicate the influence of fractional crystallization coupled with magma...

  10. Gas adsorption on crushed quartz and basalt. [in vacuum

    Science.gov (United States)

    Barker, C.; Torkelson, B. E.

    1975-01-01

    The new surfaces generated by crushing rocks and minerals adsorb gases. Different gases are adsorbed to different extents so that both the total amount and composition of the released gases are changed. This affects the interpretation of the composition of the gases obtained by vacuum crushing lunar basalts, meteorites and minerals with fluid inclusions.

  11. Petrology of spinel lherzolite xenoliths in alkali basalts from Liri ...

    African Journals Online (AJOL)

    Al2O3), and Al-rich spinel occur in alkali basalts from Liri, South of the ... these spinel lherzolite xenoliths are reported, along with the analyses of ...... erupted in the Liri region. .... and temperatures with controlled activities of water, carbon.

  12. Petrography and chemistry of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    interior through a variolitic zone. The silica-alkalies relation show these basalts to be of sub-alkaline nature. Variable normative compositions and Mg number, increase in alkali index, differences in Al2O3/CaO and FeO/MgO ratios, variable trace element...

  13. Assesment of Alkali Resistance of Basalt Used as Concrete Aggregates

    Directory of Open Access Journals (Sweden)

    al-Swaidani Aref M.

    2015-11-01

    Full Text Available The objective of this paper is to report a part of an ongoing research on the influence of using crushed basalt as aggregates on one of durability-related properties of concrete (i.e. alkali-silica reaction which is the most common form of Alkali-Aggregate Reaction. Alkali resistance has been assessed through several methods specified in the American Standards. Results of petrographic examination, chemical test (ASTM C289 and accelerated mortar bar test (ASTM C1260 have particularly been reported. In addition, the weight change and compressive strength of 28 days cured concrete containing basaltic aggregates were also reported after 90 days of exposure to 10% NaOH solution. Dolomite aggregate were used in the latter test for comparison. The experimental results revealed that basaltic rocks quarried from As-Swaida’a region were suitable for production of aggregates for concrete. According to the test results, the studied basalt aggregates can be classified as innocuous with regard to alkali-silica reaction. Further, the 10% sodium hydroxide attack did not affect the compressive strength of concrete.

  14. Basalt Waste Isolation Project. Annual report, fiscal year 1979

    International Nuclear Information System (INIS)

    1979-11-01

    This project is aimed at examining the feasibility and providing the technology to design and construct a radwaste repository in basalt formations beneath and within the Hanford Site. The project is divided into seven areas: systems integration, geosciences, hydrologic studies, engineered barriers, near-surface test facility, engineering testing, and repository engineering. This annual report summarizes key investigations in these seven areas

  15. Evaluation of basalt flows as a waste isolation media

    International Nuclear Information System (INIS)

    Deju, R.A.

    1978-01-01

    Activities in basalt waste isolation programs in the Columbia River basin are reported. Work during the period is summarized for the overall program which is divided into systems integration, geology, hydrology, engineered barriers studies, engineering testing, and the construction of a near-surface test facility

  16. Nature and composition of interbedded marine basaltic pumice in the

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 2. Nature and composition of interbedded marine basaltic pumice in the ~52–50 Ma Vastan lignite sequence, western India: Implication for Early Eocene MORB volcanism offshore Arabian Sea. Sarajit Sensarma Hukam Singh R S Rana Debajyoti Paul ...

  17. Fire performance of basalt FRP mesh reinforced HPC thin plates

    DEFF Research Database (Denmark)

    Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup

    2013-01-01

    An experimental program was carried out to investigate the influence of basalt FRP (BFRP) reinforcing mesh on the fire behaviour of thin high performance concrete (HPC) plates applied to sandwich elements. Samples with BFRP mesh were compared to samples with no mesh, samples with steel mesh...

  18. Hydrologic testing methodology and results from deep basalt boreholes

    International Nuclear Information System (INIS)

    Strait, S.R.; Spane, F.A.; Jackson, R.L.; Pidcoe, W.W.

    1982-05-01

    The objective of the hydrologic field-testing program is to provide data for characterization of the groundwater systems wihin the Pasco Basin that are significant to understanding waste isolation. The effort is directed toward characterizing the areal and vertical distributions of hydraulic head, hydraulic properties, and hydrochemistry. Data obtained from these studies provide input for numerical modeling of groundwater flow and solute transport. These models are then used for evaluating potential waste migration as a function of space and time. The groundwater system beneath the Hanford Site and surrounding area consists of a thick, accordantly layered sequence of basalt flows and associated sedimentary interbed that primarily occur in the upper part of the Columbia River basalt. Permeable horizons of the sequence are associated with the interbeds and the interflow zones within the basalt. The columnar interiors of a flow act as low-permeability aquitards, separating the more-permeable interflows or interbeds. This paper discusses the hydrologic field-gathering activities, specifically, field-testing methodology and test results from deep basalt boreholes

  19. Heat resistance study of basalt fiber material via mechanical tests

    Science.gov (United States)

    Gao, Y. Q.; Jia, C.; Meng, L.; Li, X. H.

    2017-12-01

    This paper focuses on the study of the relationship between the fracture strength of basalt rovings and temperature. Strong stretching performance of the rovings has been tested after the treatment at fixed temperatures but different heating time and then the fracture strength of the rovings exposed to the heating at different temperatures and cooled in different modes investigated. Finally, the fracture strength of the basalt material after the heat treatment was studied. The results showed that the room-temperature strength tends to decrease with an increase of the heat treatment time at 250 °C, but it has the local maximum after 2h heating. And the basalt rovings strength increased after the heat treatment up to 200 °C. It was 16.7 percent higher than the original strength. The strength depends not only on the temperature and duration of the heating, but also on the cooling mode. The value of the strength measured after cold water cooling was less by 6.3% compared with an ambient air cooling mode. The room-temperature breaking strength of the rovings heated at 200 °C and 100 °C for 2 hours each increased by about 14.6% with respect to unpretreated basalt rovings.

  20. Math Fights Flooding

    NARCIS (Netherlands)

    Besseling, Niels; Bokhove, Onno; Kolechkina, Alla; Molenaar, Jaap; van Nooyen, Ronald; Rottschäfer, Vivi; Stein, Alfred; Stoorvogel, Anton

    2008-01-01

    Due to climate changes that are expected in the coming years, the characteristics of the rainfall will change. This can potentially cause flooding or have negative influences on agriculture and nature. In this research, we study the effects of this change in rainfall and investigate what can be done

  1. Depleted basaltic lavas from the proto-Iceland plume, Central East Greenland

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Baker, Joel A.

    2012-01-01

    New geochemical and isotopic data are presented for volumetrically minor, depleted low-Ti basalts that occur in the Plateau Basalt succession of central East Greenland (CEG), formed during the initial stages of opening of the North Atlantic at 55 Ma. The basalts have MORB-like geochemistry (e.g. ...

  2. Geochemical study of young basalts in East Azerbaijan (Northwest of Iran

    Directory of Open Access Journals (Sweden)

    Nasir Amel

    2016-12-01

    Full Text Available The young basalts in East Azerbaijan are placed in West Alborz – Azerbaijan zone. Volcanic activities have extended from the Pliocene to the Quaternary by eruption from fracture systems and faults. Rocks under study are olivine-basalt and trachybasalts. The main minerals are olivine, pyroxene, plagioclase set in glassy or microcrystalline matrix and olivine are present as phenocryst. The textures in the studied rocks are mainly hyaloporphyric, hyalomicrolitic and porphyritic. Trace elements and rare earth elements on spider diagrams have high LREE/HREE ratio. Rare earth elements on diagram display negative slope indicating alkaline nature for the basalts under study. As it may be observed, on tectonic diagrams, the Marand basalts are placed on Island Arc basalt (IAB field, whereas the Ahar, Heris, Kalaibar and Miyaneh basalts are classified as Ocean Island Basalts (OIB and finally the basalts of Sohrol area are plotted on continental rift Basalt (CRB field. The Marand and Sohrol basalts were likely originated from lithospheric - astenospheric mantle with 2 to 5 % partial melting whereas, the Ahar, Heris and Kalaibar basalts having same source experienced 1-2% partial melting rate and the Miyaneh basalts possibly produced from lithospheric mantle with 10-20% partial melting rate pointing to shallow depth of mantle and the higher rate of melting. Based on tectonic setting diagrams, all the rocks studied are plotted in post collisional environments.

  3. Behaviour of rare earth elements, as natural analogues of transuranium elements, during weathering of basaltic glasses

    International Nuclear Information System (INIS)

    Daux, V.; Crovisier, J.L.; Petit, J.C.

    1991-01-01

    Subglacial basaltic glasses from Iceland have been studied in order to investigate REE behaviour low-temperature weathering. Just as actinides accumulate in the hydrated superficial corrosion layer of borosilicate glasses, REEs are found to be enriched in the natural corrosion layer of basaltic glasses (palagonite). However, this enrichment is only relative for basaltic glasses [fr

  4. Flood model for Brazil

    Science.gov (United States)

    Palán, Ladislav; Punčochář, Petr

    2017-04-01

    Looking on the impact of flooding from the World-wide perspective, in last 50 years flooding has caused over 460,000 fatalities and caused serious material damage. Combining economic loss from ten costliest flood events (from the same period) returns a loss (in the present value) exceeding 300bn USD. Locally, in Brazil, flood is the most damaging natural peril with alarming increase of events frequencies as 5 out of the 10 biggest flood losses ever recorded have occurred after 2009. The amount of economic and insured losses particularly caused by various flood types was the key driver of the local probabilistic flood model development. Considering the area of Brazil (being 5th biggest country in the World) and the scattered distribution of insured exposure, a domain covered by the model was limited to the entire state of Sao Paolo and 53 additional regions. The model quantifies losses on approx. 90 % of exposure (for regular property lines) of key insurers. Based on detailed exposure analysis, Impact Forecasting has developed this tool using long term local hydrological data series (Agencia Nacional de Aguas) from riverine gauge stations and digital elevation model (Instituto Brasileiro de Geografia e Estatística). To provide most accurate representation of local hydrological behaviour needed for the nature of probabilistic simulation, a hydrological data processing focused on frequency analyses of seasonal peak flows - done by fitting appropriate extreme value statistical distribution and stochastic event set generation consisting of synthetically derived flood events respecting realistic spatial and frequency patterns visible in entire period of hydrological observation. Data were tested for homogeneity, consistency and for any significant breakpoint occurrence in time series so the entire observation or only its subparts were used for further analysis. The realistic spatial patterns of stochastic events are reproduced through the innovative use of d-vine copula

  5. New gadiform fishes (Teleostei, Gadiformes) from the Miocene of Algeria

    Science.gov (United States)

    Carnevale, Giorgio

    2007-02-01

    As part of the completion of studies on the Miocene fishes of the Chelif Basin (north-western Algeria), this paper represents a contribution to the knowledge of the Messinian gadiform diversity of this western Mediterranean, semi-enclosed, Neogene basin. A new genus and species of the family Macrouridae is erected ( Razelainia paradoxa n. gen. et sp.), two specimens are tentatively referred to already existing taxa ( Gadiculus cf. jonas; Merluccius cf. merluccius), and a species formerly assigned to the gadid genus Brosme is transferred to the genus Gaidropsarus ( Gaidropsarus murdjadjensis). The macrourid Razelainia paradoxa n. gen. et sp. is characterized by an unusual combination of: plesiomorphic gadiform features, such as low vertebral number (presumed), well-developed caudal-fin rays, presence of a single continuous dorsal fin originating just posterior to the neurocranium, anal-fin rays slightly longer than dorsal-fin rays; and derived, typically macrourid features, such as the presence of spinoid scales and the anterior anal-fin pterygiophores extending forward over the abdominal wall. A paleoecological analysis reveals that the Messinian gadiform assemblage of the Chelif Basin had a subtropical/warm temperate affinity, with a marked north-eastern Atlantic-Mediterranean biogeographic character.

  6. Resource partitioning among top predators in a Miocene food web.

    Science.gov (United States)

    Domingo, M Soledad; Domingo, Laura; Badgley, Catherine; Sanisidro, Oscar; Morales, Jorge

    2013-01-07

    The exceptional fossil sites of Cerro de los Batallones (Madrid Basin, Spain) contain abundant remains of Late Miocene mammals. From these fossil assemblages, we have inferred diet, resource partitioning and habitat of three sympatric carnivorous mammals based on stable isotopes. The carnivorans include three apex predators: two sabre-toothed cats (Felidae) and a bear dog (Amphicyonidae). Herbivore and carnivore carbon isotope (δ(13)C) values from tooth enamel imply the presence of a woodland ecosystem dominated by C(3) plants. δ(13)C values and mixing-model analyses suggest that the two sabre-toothed cats, one the size of a leopard and the other the size of a tiger, consumed herbivores with similar δ(13)C values from a more wooded portion of the ecosystem. The two sabre-toothed cats probably hunted prey of different body sizes, and the smaller species could have used tree cover to avoid encounters with the larger felid. For the bear dog, δ(13)C values are higher and differ significantly from those of the sabre-toothed cats, suggesting a diet that includes prey from more open woodland. Coexistence of the sabre-toothed cats and the bear dog was likely facilitated by prey capture in different portions of the habitat. This study demonstrates the utility of stable isotope analysis for investigating the behaviour and ecology of members of past carnivoran guilds.

  7. Horizontal drilling in Miocene thin sand of Lake Maracaibo

    Energy Technology Data Exchange (ETDEWEB)

    Partidas, C. [PDVSA Exploration and Production (Venezuela)

    1998-12-31

    Horizontal drilling in the mature Lake Maracaibo field in Venezuela as a means of stimulating production are discussed. The Miocene sand where the horizontal well technology was applied, presented a number of intervals of unconsolidated sand of varied continuity, pay intervals at ten to twenty feet thickness, and reservoir pressures mostly at hydrostatic or below hydrostatic values. This paper evaluates a horizontal drilling program in the Lagunallis Lago Production Unit of Maracaibo, involving 91 wells to date (since 1995). When assessed in economic terms, results indicate that horizontal wells are a better economic alternative than vertical wells. The same results also showed that drainage from thin sand reservoirs resulted in better production with horizontal well technology than production from vertical wells. Payout was less than two years for 50 per cent of the horizontal wells while 40 per cent had payouts of between two and four years. Profit to investment ratio was greater than two in the case of about 70 per cent of the horizontal wells drilled in 1996. 2 tabs., 10 figs.

  8. Peatmoss (Sphagnum) diversification associated with Miocene Northern Hemisphere climatic cooling?

    Science.gov (United States)

    Shaw, A Jonathan; Devos, Nicolas; Cox, Cymon J; Boles, Sandra B; Shaw, Blanka; Buchanan, Alex M; Cave, Lynette; Seppelt, Rodney

    2010-06-01

    Global climate changes sometimes spark biological radiations that can feed back to effect significant ecological impacts. Northern Hemisphere peatlands dominated by living and dead peatmosses (Sphagnum) harbor almost 30% of the global soil carbon pool and have functioned as a net carbon sink throughout the Holocene, and probably since the late Tertiary. Before that time, northern latitudes were dominated by tropical and temperate plant groups and ecosystems. Phylogenetic analyses of mosses (phylum Bryophyta) based on nucleotide sequences from the plastid, mitochondrial, and nuclear genomes indicate that most species of Sphagnum are of recent origin (ca. Sphagnum species are not only well-adapted to boreal peatlands, they create the conditions that promote development of peatlands. The recent radiation that gave rise to extant diversity of peatmosses is temporally associated with Miocene climatic cooling in the Northern Hemisphere. The evolution of Sphagnum has had profound influences on global biogeochemistry because of the unique biochemical, physiological, and morphological features of these plants, both while alive and after death. 2010 Elsevier Inc. All rights reserved.

  9. Ecological tolerances of Miocene larger benthic foraminifera from Indonesia

    Science.gov (United States)

    Novak, Vibor; Renema, Willem

    2018-01-01

    To provide a comprehensive palaeoenvironmental reconstruction based on larger benthic foraminifera (LBF), a quantitative analysis of their assemblage composition is needed. Besides microfacies analysis which includes environmental preferences of foraminiferal taxa, statistical analyses should also be employed. Therefore, detrended correspondence analysis and cluster analysis were performed on relative abundance data of identified LBF assemblages deposited in mixed carbonate-siliciclastic (MCS) systems and blue-water (BW) settings. Studied MCS system localities include ten sections from the central part of the Kutai Basin in East Kalimantan, ranging from late Burdigalian to Serravallian age. The BW samples were collected from eleven sections of the Bulu Formation on Central Java, dated as Serravallian. Results from detrended correspondence analysis reveal significant differences between these two environmental settings. Cluster analysis produced five clusters of samples; clusters 1 and 2 comprise dominantly MCS samples, clusters 3 and 4 with dominance of BW samples, and cluster 5 showing a mixed composition with both MCS and BW samples. The results of cluster analysis were afterwards subjected to indicator species analysis resulting in the interpretation that generated three groups among LBF taxa: typical assemblage indicators, regularly occurring taxa and rare taxa. By interpreting the results of detrended correspondence analysis, cluster analysis and indicator species analysis, along with environmental preferences of identified LBF taxa, a palaeoenvironmental model is proposed for the distribution of LBF in Miocene MCS systems and adjacent BW settings of Indonesia.

  10. Influence of Flood Detention Capability in Flood Prevention for Flood Disaster of Depression Area

    OpenAIRE

    Chia Lin Chan; Yi Ju Yang; Chih Chin Yang

    2011-01-01

    Rainfall records of rainfall station including the rainfall potential per hour and rainfall mass of five heavy storms are explored, respectively from 2001 to 2010. The rationalization formula is to investigate the capability of flood peak duration of flood detention pond in different rainfall conditions. The stable flood detention model is also proposed by using system dynamic control theory to get the message of flood detention pond in this research. When rainfall freque...

  11. GIS Support for Flood Rescue

    DEFF Research Database (Denmark)

    Liang, Gengsheng; Mioc, Darka; Anton, François

    2007-01-01

    Under flood events, the ground traffic is blocked in and around the flooded area due to damages to roads and bridges. The traditional transportation network may not always help people to make a right decision for evacuation. In order to provide dynamic road information needed for flood rescue, we...... to retrieve the shortest and safest route in Fredericton road network during flood event. It enables users to make a timely decision for flood rescue. We are using Oracle Spatial to deal with emergency situations that can be applied to other constrained network applications as well....... developed an adaptive web-based transportation network application using Oracle technology. Moreover, the geographic relationships between the road network and flood areas are taken into account. The overlay between the road network and flood polygons is computed on the fly. This application allows users...

  12. Numerical simulation of flood barriers

    Science.gov (United States)

    Srb, Pavel; Petrů, Michal; Kulhavý, Petr

    This paper deals with testing and numerical simulating of flood barriers. The Czech Republic has been hit by several very devastating floods in past years. These floods caused several dozens of causalities and property damage reached billions of Euros. The development of flood measures is very important, especially for the reduction the number of casualties and the amount of property damage. The aim of flood control measures is the detention of water outside populated areas and drainage of water from populated areas as soon as possible. For new flood barrier design it is very important to know its behaviour in case of a real flood. During the development of the barrier several standardized tests have to be carried out. Based on the results from these tests numerical simulation was compiled using Abaqus software and some analyses were carried out. Based on these numerical simulations it will be possible to predict the behaviour of barriers and thus improve their design.

  13. Citizen involvement in flood risk governance: flood groups and networks

    Directory of Open Access Journals (Sweden)

    Twigger-Ross Clare

    2016-01-01

    Full Text Available Over the past decade has been a policy shift withinUK flood risk management towards localism with an emphasis on communities taking ownership of flood risk. There is also an increased focus on resilience and, more specifically, on community resilience to flooding. This paper draws on research carried out for UK Department for Environment Food and Rural Affairs to evaluate the Flood Resilience Community Pathfinder (FRCP scheme in England. Resilience is conceptualised as multidimensional and linked to exisiting capacities within a community. Creating resilience to flooding is an ongoing process of adaptation, learning from past events and preparing for future risks. This paper focusses on the development of formal and informal institutions to support improved flood risk management: institutional resilience capacity. It includes new institutions: e.g. flood groups, as well as activities that help to build inter- and intra- institutional resilience capacity e.g. community flood planning. The pathfinder scheme consisted of 13 projects across England led by local authorities aimed at developing community resilience to flood risk between 2013 – 2015. This paper discusses the nature and structure of flood groups, the process of their development, and the extent of their linkages with formal institutions, drawing out the barriers and facilitators to developing institutional resilience at the local level.

  14. Latest Miocene-earliest Pliocene evolution of the ancestral Rio Grande at the Española-San Luis Basin boundary, northern New Mexico

    Science.gov (United States)

    Daniel J. Koning,; Aby, Scott B.; Grauch, V. J.; Matthew J. Zimmerer,

    2016-01-01

    We use stratigraphic relations, paleoflow data, and 40Ar/39Ar dating to interpret net aggradation, punctuated by at least two minor incisional events, along part of the upper ancestral Rio Grande fluvial system between 5.5 and 4.5 Ma (in northern New Mexico). The studied fluvial deposits, which we informally call the Sandlin unit of the Santa Fe Group, overlie a structural high between the San Luis and Española Basins. The Sandlin unit was deposited by two merging, west- to southwest-flowing, ancestral Rio Grande tributaries respectively sourced in the central Taos Mountains and southern Taos Mountains-northeastern Picuris Mountains. The river confluence progressively shifted southwestward (downstream) with time, and the integrated river (ancestral Rio Grande) flowed southwards into the Española Basin to merge with the ancestral Rio Chama. Just prior to the end of the Miocene, this fluvial system was incised in the southern part of the study area (resulting in an approximately 4–7 km wide paleovalley), and had sufficient competency to transport cobbles and boulders. Sometime between emplacement of two basalt flows dated at 5.54± 0.38 Ma and 4.82±0.20 Ma (groundmass 40Ar/39Ar ages), this fluvial system deposited 10–12 m of sandier sediment (lower Sandlin subunit) preserved in the northern part of this paleovalley. The fluvial system widened between 4.82±0.20 and 4.50±0.07 Ma, depositing coarse sand and fine gravel up to 14 km north of the present-day Rio Grande. This 10–25 m-thick sediment package (upper Sandlin unit) buried earlier south- to southeast-trending paleovalleys (500–800 m wide) inferred from aeromagnetic data. Two brief incisional events are recognized. The first was caused by the 4.82±0.20 Ma basalt flow impounding south-flowing paleodrainages, and the second occurred shortly after emplacement of a 4.69±0.09 Ma basalt flow in the northern study area. Drivers responsible for Sandlin unit aggradation may include climate

  15. POLYPLACOPHORA FROM THE MIOCENE OF NORTH ITALY. PART 1: LEPTOCHITONIDAE, HANLEYIDAE, ISCHNOCHITONIDAE AND CALLISTOPLACIDAE

    Directory of Open Access Journals (Sweden)

    BRUNO DELL’ANGELO

    2015-11-01

    Full Text Available This study describes the chiton fauna (Mollusca, Polyplacophora from deposits of the Miocene marine sequence of North Italy, located in Piedmont and Emilia Romagna regions. This first part of the work describes the chitons pertaining to four families: Leptochitonidae, Hanleyidae, Ischnochitonidae and Callistoplacidae. The studied fossils consist of 377 valves from 13 sites (Sciolze, Valle Ceppi, Rocco di Passerano, Albugnano, Monchio di Sarzano Casina, Villa Monti, Rio di Bocca d’Asino, Sant’Agata Fossili, Vargo, Vigoleno, Montegibbio, Borelli, and Moncucco Torinese ranging from the Early Miocene (Burdigalian to the Late Miocene (Messinian. We identified 16 species, 12 of which were already known, two are identified only at generic level (Stenosemus sp. A & sp. B, and two are described as new: Parachiton statianus sp. n., and Callistochiton borellianus sp. n. Some species found are particularly noteworthy; Lepidopleurus benoisti is the new name attributed to the species previously known as Middendorffia subcajetana or Gymnoplax orbignyi, based on the study of the type material; Leptochiton salicensis, previously known only from the Early Pleistocene of Salice (Messina, Sicily; Hanleya mediterranea is reported for the first time from the Miocene of Italy; Ischnochiton ligusticus, previously known only from the Early Pliocene of Western Liguria; the distribution of Stenoplax paviai, recently described from the Late Miocene (Rio di Bocca d’Asino, is extended to the Early Miocene (Langhian. A complete discussion on the chiton fauna from the North Italian Miocene, consisting of all the species treated in both parts, will be given in the second part of this work.

  16. Surface modification of basalt with silane coupling agent on asphalt mixture moisture damage

    Energy Technology Data Exchange (ETDEWEB)

    Min, Yahong; Fang, Ying; Huang, Xiaojun; Zhu, Yinhui; Li, Wensheng [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Yuan, Jianmin [College of Materials Engineering, Hunan University, Changsha, 410082 (China); Tan, Ligang [College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082 (China); Wang, Shuangyin [State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wu, Zhenjun, E-mail: wooawt@163.com [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China)

    2015-08-15

    Graphical abstract: - Highlights: • A new silane coupling agent was synthesized based on KH570. • Basalt surface was modified using the new silane coupling agent. • Chemical bond between basalt and the new silane coupling agent was formed. • Asphalt mixture which used modified basalt show superior water stability. - Abstract: A new silane coupling agent was synthesized based on γ-(methacryloyloxy) propyltrimethoxysilane (KH570). The surface of basalt rocks was modified by KH570 and the new silane coupling agent (NSCA), and the interfacial interaction between silane coupling agent and basalt was also studied. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis showed that the silane coupling agent molecule bound strongly with basalt rocks. Scanning electronic microscopy (SEM) observation showed that a thin layer of coupling agent was formed on the surface of modified basalt. The boiling test and immersion Marshall test confirmed that the moisture sensitivity of basalt modified with the new silane coupling agent increased more significantly than that untreated and treated with KH570. The Retained Marshall Strength of basalt modified with the new coupling agent increased from 71.74% to 87.79% compared with untreated basalt. The results indicated that the new silane coupling agent played an important role in improving the interfacial performance between basalt and asphalt.

  17. Miocene squat lobsters (Decapoda, Anomura, Galatheoidea) of the Central Paratethys - a review, with description of a new species of Munidopsis.

    Science.gov (United States)

    Hyžný, M; Gašparič, R; Robins, C M; Schlögl, J

    2014-10-01

    All squat lobsters of the families Galatheidae, Munididae and Munidopsidae from the Miocene of the Central Paratethys are reviewed taxonomically. Based on additional observations emended diagnoses are provided for Agononida cerovensis and Galathea weinfurteri , from the Lower and Middle Miocene, respectively. Munidopsis is represented by two species in the study area; additional data for M. lieskovensis from the Lower Miocene of Slovakia are presented and a new species, M. palmuelleri , from the Middle Miocene of Slovenia is erected. Implications for palaeoenvironmental reconstructions are briefly discussed for each taxon.

  18. Investigation on mechanical properties of basalt composite fabrics (experiment study)

    Science.gov (United States)

    Talebi Mazraehshahi, H.; Zamani, H.

    2010-06-01

    To fully appreciate the role and application of composite materials to structures, correct understanding of mechanical behaviors required for selection of optimum material. Fabric reinforced composites are composed of a matrix that is reinforced with pliable fabric, glass fabric is most popular reinforcement for different application specially in aircraft structure, although other fabric material are also used. At this study new fabric material called basalt with epoxy resin introduced and mechanical behaviors of this material investigated from view point of testing. For this study two type of fabric with different thickness used. Comparison between this composite reinforcement with popular reinforcement as carbon, glass, kevlar performed. To determine mechanical properties of epoxy based basalt fabric following test procedure performed : 1). Tensile testing according to ASTM D3039 in 0° and 90° direction to find ultimate strength in tension and shear, modulus of elasticity, elangation and ultimate strain. 2). Compression testing according to EN 2850 ultimate compression strength and maximum deformation under compression loading. 3). Shear testing according to ASTM D3518-94 to find in plane shear response of polymer matrix composites materials. 4). Predict flexural properties of sandwich construction which manufactured from basalt facing with PVC foam core according to ASTM C393-94. Material strength properties must be based on enough tests of material to meet the test procedure specifications [1]. For this reason six specimens were manufactured for testing and the tests were performed on them using an INSTRON machine model 5582. In the study, the effect of percent of resin in basalt reinforced composite was investigated. Also the weights of the ballast based composites with different percent of resin were measured with conventional composites. As the weight is an important parameter in aerospace industry when the designer wants to replace one material with

  19. Investigation on mechanical properties of basalt composite fabrics (experiment study

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.

    2010-06-01

    Full Text Available To fully appreciate the role and application of composite materials to structures, correct understanding of mechanical behaviors required for selection of optimum material. Fabric reinforced composites are composed of a matrix that is reinforced with pliable fabric, glass fabric is most popular reinforcement for different application specially in aircraft structure, although other fabric material are also used. At this study new fabric material called basalt with epoxy resin introduced and mechanical behaviors of this material investigated from view point of testing. For this study two type of fabric with different thickness used. Comparison between this composite reinforcement with popular reinforcement as carbon, glass, kevlar performed. To determine mechanical properties of epoxy based basalt fabric following test procedure performed : 1. Tensile testing according to ASTM D3039 in 0° and 90° direction to find ultimate strength in tension and shear, modulus of elasticity, elangation and ultimate strain. 2. Compression testing according to EN 2850 ultimate compression strength and maximum deformation under compression loading. 3. Shear testing according to ASTM D3518-94 to find in plane shear response of polymer matrix composites materials. 4. Predict flexural properties of sandwich construction which manufactured from basalt facing with PVC foam core according to ASTM C393-94. Material strength properties must be based on enough tests of material to meet the test procedure specifications [1]. For this reason six specimens were manufactured for testing and the tests were performed on them using an INSTRON machine model 5582. In the study, the effect of percent of resin in basalt reinforced composite was investigated. Also the weights of the ballast based composites with different percent of resin were measured with conventional composites. As the weight is an important parameter in aerospace industry when the designer wants to replace one

  20. Basalt characterization by means of nuclear and electrical well logging techniques. Case study from Southern Syria

    International Nuclear Information System (INIS)

    Asfahani, Jamal

    2011-01-01

    Nuclear well logging, including natural gamma ray, density, and neutron-porosity techniques are used with electrical well logging of long and short normal techniques to characterize the basaltic areas largely extended in Southern Syria. Statistical analysis approach with the threshold concept has been adapted for such characterization, where four kinds of basalt have been identified: very hard basalt, hard basalt, fractured basalt, and basalt alteration products. The spectrometric gamma technique has also been applied on the retrieved rock samples in order to determine the radioactive content (eU, eTh, and K%) of the basaltic section in the study area. No radioactive anomalies have been detected, the radioactive values are normal and in the expected range.

  1. Floods and tsunamis.

    Science.gov (United States)

    Llewellyn, Mark

    2006-06-01

    Floods and tsunamis cause few severe injuries, but those injuries can overwhelm local areas, depending on the magnitude of the disaster. Most injuries are extremity fractures, lacerations, and sprains. Because of the mechanism of soft tissue and bone injuries, infection is a significant risk. Aspiration pneumonias are also associated with tsunamis. Appropriate precautionary interventions prevent communicable dis-ease outbreaks. Psychosocial health issues must be considered.

  2. Identification of flood-rich and flood-poor periods in flood series

    Science.gov (United States)

    Mediero, Luis; Santillán, David; Garrote, Luis

    2015-04-01

    Recently, a general concern about non-stationarity of flood series has arisen, as changes in catchment response can be driven by several factors, such as climatic and land-use changes. Several studies to detect trends in flood series at either national or trans-national scales have been conducted. Trends are usually detected by the Mann-Kendall test. However, the results of this test depend on the starting and ending year of the series, which can lead to different results in terms of the period considered. The results can be conditioned to flood-poor and flood-rich periods located at the beginning or end of the series. A methodology to identify statistically significant flood-rich and flood-poor periods is developed, based on the comparison between the expected sampling variability of floods when stationarity is assumed and the observed variability of floods in a given series. The methodology is applied to a set of long series of annual maximum floods, peaks over threshold and counts of annual occurrences in peaks over threshold series observed in Spain in the period 1942-2009. Mediero et al. (2014) found a general decreasing trend in flood series in some parts of Spain that could be caused by a flood-rich period observed in 1950-1970, placed at the beginning of the flood series. The results of this study support the findings of Mediero et al. (2014), as a flood-rich period in 1950-1970 was identified in most of the selected sites. References: Mediero, L., Santillán, D., Garrote, L., Granados, A. Detection and attribution of trends in magnitude, frequency and timing of floods in Spain, Journal of Hydrology, 517, 1072-1088, 2014.

  3. Pre-Miocene birth of the Yangtze River

    Science.gov (United States)

    Zheng, Hongbo; Clift, Peter D.; Wang, Ping; Tada, Ryuji; Jia, Juntao; He, Mengying; Jourdan, Fred

    2013-01-01

    The development of fluvial systems in East Asia is closely linked to the evolving topography following India–Eurasia collision. Despite this, the age of the Yangtze River system has been strongly debated, with estimates ranging from 40 to 45 Ma, to a more recent initiation around 2 Ma. Here, we present 40Ar/39Ar ages from basalts interbedded with fluvial sediments from the lower reaches of the Yangtze together with detrital zircon U–Pb ages from sand grains within these sediments. We show that a river containing sediments indistinguishable from the modern river was established before ∼23 Ma. We argue that the connection through the Three Gorges must postdate 36.5 Ma because of evaporite and lacustrine sedimentation in the Jianghan Basin before that time. We propose that the present Yangtze River system formed in response to regional extension throughout eastern China, synchronous with the start of strike–slip tectonism and surface uplift in eastern Tibet and fed by strengthened rains caused by the newly intensified summer monsoon. PMID:23610418

  4. The development of flood map in Malaysia

    Science.gov (United States)

    Zakaria, Siti Fairus; Zin, Rosli Mohamad; Mohamad, Ismail; Balubaid, Saeed; Mydin, Shaik Hussein; MDR, E. M. Roodienyanto

    2017-11-01

    In Malaysia, flash floods are common occurrences throughout the year in flood prone areas. In terms of flood extent, flash floods affect smaller areas but because of its tendency to occur in densely urbanized areas, the value of damaged property is high and disruption to traffic flow and businesses are substantial. However, in river floods especially the river floods of Kelantan and Pahang, the flood extent is widespread and can extend over 1,000 square kilometers. Although the value of property and density of affected population is lower, the damage inflicted by these floods can also be high because the area affected is large. In order to combat these floods, various flood mitigation measures have been carried out. Structural flood mitigation alone can only provide protection levels from 10 to 100 years Average Recurrence Intervals (ARI). One of the economically effective non-structural approaches in flood mitigation and flood management is using a geospatial technology which involves flood forecasting and warning services to the flood prone areas. This approach which involves the use of Geographical Information Flood Forecasting system also includes the generation of a series of flood maps. There are three types of flood maps namely Flood Hazard Map, Flood Risk Map and Flood Evacuation Map. Flood Hazard Map is used to determine areas susceptible to flooding when discharge from a stream exceeds the bank-full stage. Early warnings of incoming flood events will enable the flood victims to prepare themselves before flooding occurs. Properties and life's can be saved by keeping their movable properties above the flood levels and if necessary, an early evacuation from the area. With respect to flood fighting, an early warning with reference through a series of flood maps including flood hazard map, flood risk map and flood evacuation map of the approaching flood should be able to alert the organization in charge of the flood fighting actions and the authority to

  5. Swiss Re Global Flood Hazard Zones: Know your flood risk

    Science.gov (United States)

    Vinukollu, R. K.; Castaldi, A.; Mehlhorn, J.

    2012-12-01

    Floods, among all natural disasters, have a great damage potential. On a global basis, there is strong evidence of increase in the number of people affected and economic losses due to floods. For example, global insured flood losses have increased by 12% every year since 1970 and this is expected to further increase with growing exposure in the high risk areas close to rivers and coastlines. Recently, the insurance industry has been surprised by the large extent of losses, because most countries lack reliable hazard information. One example has been the 2011 Thailand floods where millions of people were affected and the total economic losses were 30 billion USD. In order to assess the flood risk across different regions and countries, the flood team at Swiss Re based on a Geomorphologic Regression approach, developed in house and patented, produced global maps of flood zones. Input data for the study was obtained from NASA's Shuttle Radar Topographic Mission (SRTM) elevation data, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) and HydroSHEDS. The underlying assumptions of the approach are that naturally flowing rivers shape their channel and flood plain according to basin inherent forces and characteristics and that the flood water extent strongly depends on the shape of the flood plain. On the basis of the catchment characteristics, the model finally calculates the probability of a location to be flooded or not for a defined return period, which in the current study was set to 100 years. The data is produced at a 90-m resolution for latitudes 60S to 60N. This global product is now used in the insurance industry to inspect, inform and/or insure the flood risk across the world.

  6. A Miocene wave-dominated estuarine system in the Paraíba Basin, northeastern Brazil

    Science.gov (United States)

    Gandini, Rosana; Rossetti, Dilce de Fátima; Netto, Renata Guimarães; Góes, Ana Maria

    2017-11-01

    A number of publications have documented the effect of the Miocene transgression on several coasts of the world. However, this event is incompletely documented along the Brazilian margin, despite the existence of an impressive record of Miocene deposits exposed mostly as several coastal cliffs along more than 5000 km of distance. The transgressive nature of Miocene deposits, so far recognized only in a few localities of northeastern Brazil, needs to be amplified in order to better characterize the impact of the Miocene transgression in eastern South America. In this work, we provide facies analysis of early/middle Miocene strata exposed in the Paraíba Basin, northeastern Brazil, aiming reconstruct the depositional paleoenvironments and analyze their evolution within the context of relative sea-level fluctuations data. The results revealed deposits characterized by several features that were related to the action of tidal currents, such as alternating thicker/thinner forest packages, abundant reactivation surfaces, mud drapes and oppositely-dipping (herringbone) cross sets. These sedimentary structures were associated with an ichnological assemblage indicative of marine-influenced and brackish water, best represented by Ophiomorpha, Planolites-Palaeophycus-Thalassinoides and Thallassinoides-Planolites-Palaeophycus ichnofabrics. Sedimentation occurred in environments consisting of estuarine channel, estuarine central basin, tidal inlet/tidal channel, tidal delta/washover, tidal flat/shoal and foreshore, which were related to an estuarine setting, at least in part of a wave-dominated type. Analysis of facies stratal patterns led to suggest that the estuarine deposits of the Paraíba Basin reflect a rise in relative sea level probably during the transgressive and/or highstand stage of a depositional sequence formed directly overlying Cretaceous rocks. This rise can be correlated with the worldwide early/mid Miocene marine transgression. However, while the eustatic sea

  7. Provenance of the lower Miocene of the Gulf of Mexico from detrital zircon double dating

    Science.gov (United States)

    xu, J.

    2013-12-01

    The lower Miocene interval of the Gulf of Mexico (GOM) has recently gained increasing attention from oil and gas industry due to its hydrocarbon potential below the salt canopy. However, it has been less well studied than both the underlying Oligocene and overlying middle Miocene strata. The lower Miocene worldwide is a transitional period of tectonic, climatic, and oceanographic change. In particular, it is a period of major tectonic reorganization in the western interior of North America (Rocky Mountains), involving a shift from the Oligocene thermal phase, with abundant volcanic activity recorded in the thick Frio/Vicksburg succession of the GOM, to the Miocene Basin-Range extensional phase. Climatic conditions also changed from a relatively arid Oligocene to wetter Miocene, resulting in increased sediment yields from exhumed tectonic structures. Previous provenance studies used proportions of quartz, feldspar and lithic fragments and consideration of likely river courses through known paleogeomorphological elements. Only limited detrital zircon (DZ) U-Pb studies on Paleocene strata have been undertaken and there has been no previous U-Pb and (U-Th)/He double dating in the GOM. In this study we apply the latest analytical approaches, such as DZ U-Pb dating to gain robust source terranes ages and more fully elucidate the complex sediment provenance and dispersal history of GOM. We also employ DZ (U-Th)/He (ZHe) dating, combined with DZ U-Pb, to not only define sedimentary provenance but also the exhumation histories of detrital source regions. Samples of lower Miocene outcrop exposures in Texas and Louisiana have been collected to discriminate the varied tectonic and drainage system changes across the basin in lateral. In addition, samples from the Eocene, Oligocene and middle Miocene have been obtained to reveal vertical shift of source terranes contributions. Our initial age data show detrital zircons of lower Miocene sediments come from a wide range of source

  8. Recent advances in flood forecasting and flood risk assessment

    Directory of Open Access Journals (Sweden)

    G. Arduino

    2005-01-01

    Full Text Available Recent large floods in Europe have led to increased interest in research and development of flood forecasting systems. Some of these events have been provoked by some of the wettest rainfall periods on record which has led to speculation that such extremes are attributable in some measure to anthropogenic global warming and represent the beginning of a period of higher flood frequency. Whilst current trends in extreme event statistics will be difficult to discern, conclusively, there has been a substantial increase in the frequency of high floods in the 20th century for basins greater than 2x105 km2. There is also increasing that anthropogenic forcing of climate change may lead to an increased probability of extreme precipitation and, hence, of flooding. There is, therefore, major emphasis on the improvement of operational flood forecasting systems in Europe, with significant European Community spending on research and development on prototype forecasting systems and flood risk management projects. This Special Issue synthesises the most relevant scientific and technological results presented at the International Conference on Flood Forecasting in Europe held in Rotterdam from 3-5 March 2003. During that meeting 150 scientists, forecasters and stakeholders from four continents assembled to present their work and current operational best practice and to discuss future directions of scientific and technological efforts in flood prediction and prevention. The papers presented at the conference fall into seven themes, as follows.

  9. Public perception of flood risks, flood forecasting and mitigation

    Directory of Open Access Journals (Sweden)

    M. Brilly

    2005-01-01

    Full Text Available A multidisciplinary and integrated approach to the flood mitigation decision making process should provide the best response of society in a flood hazard situation including preparation works and post hazard mitigation. In Slovenia, there is a great lack of data on social aspects and public response to flood mitigation measures and information management. In this paper, two studies of flood perception in the Slovenian town Celje are represented. During its history, Celje was often exposed to floods, the most recent serious floods being in 1990 and in 1998, with a hundred and fifty return period and more than ten year return period, respectively. Two surveys were conducted in 1997 and 2003, with 157 participants from different areas of the town in the first, and 208 in the second study, aiming at finding the general attitude toward the floods. The surveys revealed that floods present a serious threat in the eyes of the inhabitants, and that the perception of threat depends, to a certain degree, on the place of residence. The surveys also highlighted, among the other measures, solidarity and the importance of insurance against floods.

  10. Geochemical Characteristics of Cenozoic Jining Basalts of the Western North China Craton: Evidence for the Role of the Lower Crust, Lithosphere, and Asthenosphere in Petrogenesis

    Directory of Open Access Journals (Sweden)

    Kung-Suan Ho

    2011-01-01

    Full Text Available The Jining volcanic field located in the southern margin of the Mongolian plateau and the western North China Block consists of four rock types: quartz tholeiite, olivine tholeiite, alkali olivine basalt and basanite. These rocks have a wide range of K-Ar ages from ~36 to < 0.2 Ma. The early volcanism was voluminous and dominated by flood-type fissure eruptions of tholeiites, whereas the later phase was represented by sparse eruptions of basanitic lavas. Thirty-six samples analyzed in this study show a wide range in SiO2 contents from 44% ~ 54%. They all are sodium-rich and high-Ti basalts that, however, show marked isotopic variations between two end-members: (1 tholeiites that have higher 87Sr/86Sr of 0.7048 ~ 0.7052, and lower £`Nd of -0.8 to -2.4 and Pb isotope ratios (206Pb/204Pb of 16.9 ~ 17.2, 207Pb/204Pb of 15.3 ~ 15.4 and 208Pb/204Pb of 37.1 ~ 37.7; and (2 basanites that have lower 87Sr/86Sr of 0.7035 ~ 0.7044, and higher £`Nd of +1.3 to +4.9 and Pb isotope ratios (206Pb/204Pb of 17.7 ~ 18.0, 207Pb/204Pb of 15.4 ~ 15.5 and 208Pb/204Pb of 37.8 ~ 38.2. Alkali olivine basalt that occurs as a subordinate rock type is geochemically similar to the basanites, but isotopically similar to the tholeiites, characterized by the highest 87Sr/86Sr ratio among the three basaltic suites, coupled with a low Nb/U value (~33.

  11. Basaltic rocks analyzed by the Spirit rover in Gusev crater

    Science.gov (United States)

    McSween, H.Y.; Arvidson, R. E.; Bell, J.F.; Blaney, D.; Cabrol, N.A.; Christensen, P.R.; Clark, B. C.; Crisp, J.A.; Crumpler, L.S.; Des Marias, D.J.; Farmer, J.D.; Gellert, Ralf; Ghosh, A.; Gorevan, S.; Graff, T.; Grant, J.; Haskin, L.A.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B.L.; Klingelhoefer, G.; Knudson, A.T.; McLennan, S.; Milam, K.A.; Moersch, J.E.; Morris, R.V.; Rieder, R.; Ruff, S.W.; De Souza, P.A.; Squyres, S. W.; Wanke, H.; Wang, A.; Wyatt, M.B.; Yen, A.; Zipfel, J.

    2004-01-01

    The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain ???25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mo??ssbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust.

  12. Mars weathering analogs - Secondary mineralization in Antarctic basalts

    Science.gov (United States)

    Berkley, J. L.

    1982-01-01

    Alkalic basalt samples from Ross Island, Antarctica, are evaluated as terrestrial analogs to weathered surface materials on Mars. Secondary alteration in the rocks is limited to pneumatolytic oxidation of igneous minerals and glass, rare groundmass clay and zeolite mineralization, and hydrothermal minerals coating fractures and vesicle surfaces. Hydrothermal mineral assemblages consist mainly of K-feldspar, zeolites (phillipsite and chabazite), calcite, and anhydrite. Low alteration rates are attributed to cold and dry environmental factors common to both Antarctica and Mars. It is noted that mechanical weathering (aeolian abrasion) of Martian equivalents to present Antarctic basalts would yield minor hydrothermal minerals and local surface fines composed of primary igneous minerals and glass but would produce few hydrous products, such as palagonite, clay or micas. It is thought that leaching of hydrothermal vein minerals by migrating fluids and redeposition in duricrust deposits may represent an alternate process for incorporating secondary minerals of volcanic origin into Martian surface fines.

  13. Petrogeochemistry of Mesozoic basaltic volcanics in Daqingshan area

    International Nuclear Information System (INIS)

    Li Xiaoguang; Li Ziying; Wei Sanyuan; Qi Da'neng

    2009-01-01

    Through the discussion on petrogeochemistry of Later Mesozoic basaltic volcanics in Daqingshan Basin in Manzhouli area, combined with field observation and the predecessors' study, its magma evolution,genesis and diagenetic structural environment are discussed, and some suggestion are provided for the further work. Basaltic magma in this area is believed to be derived from mantle with incompatible elements which were later participated by some crustal materials. It is a partially melting product of mantle by early metasomatized fluid under lithosphere extension. Through petrogeochemical analysis of the volcanics and the contrast to the adjacent uranium-producing volcanics, it is concluded that this region has structural environment to form magma evolution series which are more favorable for volcanic hydrothermal-type uranium and polymetallic mineralization. (authors)

  14. Americium migration in basalt and implications to repository risk analysis

    International Nuclear Information System (INIS)

    Rickert, P.G.

    1980-01-01

    Experiments were performed with americium as a minor component in groundwater. Batch adsorption, migration through column, and filtration experiments were performed. It was determined in batch experiments that americium is strongly adsorbed from solution. It was determined with filtration experiments that large percentages of the americium concentrations suspended by the contact solutions in batch experiments and suspended by the infiltrating groundwater in migration experiments were associated with particulate. Filtration was determined to be the primary mode of removal of americium from infiltrating groundwater in a column of granulated basalt (20 to 50 mesh) and an intact core of permeable basalt. Fractionally, 0.46 and 0.22 of the americium component in the infiltrating groundwater was transported through the column and core respectively. In view of these filtration and migration experiment results, the concept of K/sub d/ in the chromatographic sense is meaningless for predicting americium migration in bedrock by groundwater transport at near neutral pH

  15. Quaternary basaltic volcanism in the Payenia volcanic province, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina

    primitive basalts and trachybasalts but also more evolved samples from the retroarc region and the larger volcanoes Payún Matrú and Payún Liso are presented. The samples cover a broad range of compositions from intraplate lavas similar to ocean island basalts to arc andesites. A common feature found...... are isotopically similar to the Andean Southern Volcanic Zone arc rocks and their mantle source possibly resembled the source of South Atlantic N-MORB prior to addition of fluids and melts from the subduction channel. However, it must have been more enriched than the estimates of depleted upper mantle from...... the lithosphere is thinnest and possibly in areas of elevated mantle temperatures. The pyroxenite melts formed at deeper levels react with the surrounding peridotite and thereby changes composition leading to eruption of melts which experienced variable degrees of melt-peridotite interaction. This can presumably...

  16. Environmental resistance and mechanical performance of basalt and glass fibers

    International Nuclear Information System (INIS)

    Wei Bin; Cao Hailin; Song Shenhua

    2010-01-01

    The treated basalt and glass fibers with sodium hydroxide and hydrochloric acid solutions for different times were analyzed, respectively. This paper summarized the mass loss ratio and the strength maintenance ratios of the fibers after treatment. The fibers' surface corrosion morphologies were characterized using scanning electron microscopy and their compositions were detected using energy dispersive X-ray spectroscopy. The acid resistance was much better than the alkali resistance for the basalt fibers. Nevertheless, for the glass fibers the situation is different: the acid resistance was almost the same as the alkali resistance. Among the two types of aqueous environments evaluated, the alkali solution is the most aggressive to the fibers' surface. The possible corrosion mechanisms are revealed.

  17. A new basaltic glass microanalytical reference material for multiple techniques

    Science.gov (United States)

    Wilson, Steve; Koenig, Alan; Lowers, Heather

    2012-01-01

    The U.S. Geological Survey (USGS) has been producing reference materials since the 1950s. Over 50 materials have been developed to cover bulk rock, sediment, and soils for the geological community. These materials are used globally in geochemistry, environmental, and analytical laboratories that perform bulk chemistry and/or microanalysis for instrument calibration and quality assurance testing. To answer the growing demand for higher spatial resolution and sensitivity, there is a need to create a new generation of microanalytical reference materials suitable for a variety of techniques, such as scanning electron microscopy/X-ray spectrometry (SEM/EDS), electron probe microanalysis (EPMA), laser ablation inductively coupled mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS). As such, the microanalytical reference material (MRM) needs to be stable under the beam, be homogeneous at scales of better than 10–25 micrometers for the major to ultra-trace element level, and contain all of the analytes (elements or isotopes) of interest. Previous development of basaltic glasses intended for LA-ICP-MS has resulted in a synthetic basaltic matrix series of glasses (USGS GS-series) and a natural basalt series of glasses (BCR-1G, BHVO-2G, and NKT-1G). These materials have been useful for the LA-ICP-MS community but were not originally intended for use by the electron or ion beam community. A material developed from start to finish with intended use in multiple microanalytical instruments would be useful for inter-laboratory and inter-instrument platform comparisons. This article summarizes the experiments undertaken to produce a basalt glass reference material suitable for distribution as a multiple-technique round robin material. The goal of the analytical work presented here is to demonstrate that the elemental homogeneity of the new glass is acceptable for its use as a reference material. Because the round robin exercise is still underway, only

  18. Basalt-trachybasalt samples in Gale Crater, Mars

    International Nuclear Information System (INIS)

    Edwards, Peter H.; Anderson, Ryan B.; Dyar, Darby

    2017-01-01

    The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single-laser-shot spectra of igneous targets observed by ChemCam shows a strong peak at ~55 wt% SiO 2 and 6 wt% total alkalis, with a minor secondary maximum at 47–51 wt% SiO 2 and lower alkali content. The centers of these distributions, together with the rock textures, indicate that many of the ChemCam igneous targets are trachybasalts, Mg# = 27 but with a secondary concentration of basaltic material, with a focus of compositions around Mg# = 54. We suggest that all of these igneous rocks resulted from low-pressure, olivine-dominated fractionation of Adirondack (MER) class-type basalt compositions. This magmatism has subalkaline, tholeiitic affinities. The similarity of the basalt endmember to much of the Gale sediment compositions in the first 1000 sols of the MSL mission suggests that this type of Fe-rich, relatively low-Mg#, olivine tholeiite is the dominant constituent of the Gale catchment that is the source material for the fine-grained sediments in Gale. The similarity to many Gusev igneous compositions suggests that it is a major constituent of ancient Martian magmas, and distinct from the shergottite parental melts thought to be associated with Tharsis and the Northern Lowlands. Finally, the Gale Crater catchment sampled a mixture of this tholeiitic basalt along with alkaline igneous material, together giving some analogies to terrestrial intraplate magmatic provinces.

  19. Basaltic Shergottite NWA 856: Differentiation of a Martian Magma

    Science.gov (United States)

    Ferdous, J.; Brandon, A. D.; Peslier, A. H.; Pirotte, Z.

    2016-01-01

    NWA 856 or Djel Ibone, is a basaltic shergottite discovered as a single stone of 320 g in South Morocco in April, 2001. This meteorite is fresh, i.e. shows minimal terrestrial weathering for a desert find. No shergottite discovered in North Africa can be paired with NWA 856. The purpose of this study is to constrain its crystallization history using textural observations, crystallization sequence modeling and in-situ trace element analysis in order to understand differentiation in shergottite magmatic systems.

  20. Rock mass deformation properties of closely jointed basalt

    International Nuclear Information System (INIS)

    Kim, K.; Cramer, M.L.

    1982-12-01

    The deformational behavior of the Columbia River basalt is being investigated as part of a comprehensive site characterization program intended to determine the feasibility of constructing a nuclear waste repository in basalt at Hanford, Washington. Direct field measurements were conducted in a 2-m cube of basalt to obtain truly representative rock mass deformation properties. Load was applied to the test block in three orthogonal directions through the use of flat jacks in two perpendicular planes and a cable anchor system in the third. This configuration allowed the block to be placed in a simulated triaxial stress state at stress levels up to 12.5 MPa. The deformation at the center of the test block was monitored through the use of an optical measurement system developed for this project. The results indicate that the vertically oriented columnar joints have a significant influence on the deformation behavior of the basalt. The modulus in the direction parallel to the column axis was approx. 30 GPa, while the modulus value perpendicular to the columns was approx. 20 GPa. Laboratory measurements of intact specimens taken from this area yielded a value of 80 GPa with no indication of anisotropy. Hysteresis was observed in all loading cycles, but was distinctly more pronounced perpendicular to the column axis, indicative of significant joint displacement in this direction. The results of this test represent the first true rock mass modulus data obtained in closely jointed rock on a large scale. These measurement methods have eliminated many of the ambiguities associated with borehole jacking and surface measurement techniques

  1. Flooding correlations in narrow channel

    International Nuclear Information System (INIS)

    Kim, S. H.; Baek, W. P.; Chang, S. H.

    1999-01-01

    Heat transfer in narrow gap is considered as important phenomena in severe accidents in nuclear power plants. Also in heat removal of electric chip. Critical heat flux(CHF) in narrow gap limits the maximum heat transfer rate in narrow channel. In case of closed bottom channel, flooding limited CHF occurrence is observed. Flooding correlations will be helpful to predict the CHF in closed bottom channel. In present study, flooding data for narrow channel geometry were collected and the work to recognize the effect of the span, w and gap size, s were performed. And new flooding correlations were suggested for high-aspect-ratio geometry. Also, flooding correlation was applied to flooding limited CHF data

  2. Flood Hazards - A National Threat

    Science.gov (United States)

    ,

    2006-01-01

    In the late summer of 2005, the remarkable flooding brought by Hurricane Katrina, which caused more than $200 billion in losses, constituted the costliest natural disaster in U.S. history. However, even in typical years, flooding causes billions of dollars in damage and threatens lives and property in every State. Natural processes, such as hurricanes, weather systems, and snowmelt, can cause floods. Failure of levees and dams and inadequate drainage in urban areas can also result in flooding. On average, floods kill about 140 people each year and cause $6 billion in property damage. Although loss of life to floods during the past half-century has declined, mostly because of improved warning systems, economic losses have continued to rise due to increased urbanization and coastal development.

  3. Interim reclamation report, Basalt Waste Isolation project: Boreholes, 1989

    International Nuclear Information System (INIS)

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.

    1990-03-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. An extensive site characterization program was begun to determine the feasibility of using the basalts beneath the Hanford Site for the repository. Site research focused primarily on determining the direction and speed of groundwater movement, the uniformity of basalt layers, and tectonic stability. Some 98 boreholes were sited, drilled, deepened, or modified by BWIP between 1977 and 1988 to test the geologic properties of the Site. On December 22, 1987, President Reagan signed into law the Nuclear Waste Policy Amendments Act of 1987, which effectively stopped all repository-related activities except reclamation of disturbed lands at the Hanford Site. This report describes the development of the reclamation program for the BWIP boreholes, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 48 refs., 28 figs., 14 tabs

  4. The Age of Rift-Related Basalts in East Antarctica

    Science.gov (United States)

    Leitchenkov, G. L.; Belyatsky, B. V.; Kaminsky, V. D.

    2018-01-01

    The Lambert Rift, which is a large intracontinental rift zone in East Antarctica, developed over a long period of geological time, beginning from the Late Paleozoic, and its evolution was accompanied by magmatic activity. The latest manifestation of magmatism is eruption of alkaline olivine-leucite basalts on the western side of the Lambert Rift; Rb-Sr dating referred its time to the Middle Eocene, although its genesis remained vague. In order to solve this problem, we found geochronometer minerals in basaltic samples and 68 apatite grains appeared to be suitable for analysis. Their ages and ages of host basalts, determined by the U-Pb local method on the SIMS SHRIMP-II, were significantly different (323 ± 31 Ma) from those assumed earlier. This age corresponds to the earliest stage of crustal extension in East Antarctica and to most of Gondwana. The new data crucially change the ideas about the evolution of Lambert Rift and demonstrate the ambiguity of K-Ar dates of the alkali effusive formed under long-term rifting.

  5. Basalt Waste Isolation Project. Annual report, fiscal year 1980

    International Nuclear Information System (INIS)

    1980-11-01

    During this fiscal year the information available in the fields of geology and hydrology of the Columbia Plateau was consolidated and two reports were issued summarizing this information. In addition, the information on engineered barriers was consolidated and a report summarizing the research to date on waste package development and design of borehole seals was prepared. The waste package studies, when combined with the hydrologic integration, revealed that even under extreme disruptive conditions, a repository in basalt with appropriately designed waste packages can serve as an excellent barrier for containment of radionuclides for the long periods of time required for waste isolation. On July 1, 1980, the first two heater tests at the Near-Surface Test Facility were started and have been successfully operated to this date. The papers on the Near-Surface Test Facility section of this report present the results of the equipment installed and the preliminary results of the testing. In October 1979, the US Department of Energy selected the joint venture of Kaiser Engineers/Parsons Brinckerhoff Quade and Douglas, Inc., to be the architect-engineer to produce a conceptual design of a repository in basalt. During the year, this design has progressed and concept selection has now been completed. This annual report presents a summary of the highlights of the work completed during fiscal year 1980. It is intended to supplement and summarize the nearly 200 papers and reports that have been distributed to date as a part of the Basalt Waste Isolation Project studies

  6. Dissolution of basaltic glass in seawater: Mechanism and rate

    International Nuclear Information System (INIS)

    Crovisier, J.L.; Honnorez, J.; Eberhart, J.P.

    1987-01-01

    Basaltic glasses are considered as natural analogues for nuclear waste glasses. Thermodynamic computer codes used to evaluate long term behavior of both nuclear waste and basaltic glasses require the knowledge of the dissolution mechanism of the glass network. The paper presents the results of a series of experiments designed to study the structure and chemical composition of alteration layers formed on the surface of artificial tholeiitic glass altered in artificial seawater. Experiments were performed at 60 degree C, 1 bar and 350 bars in non-renewed conditions. A natural sample from Palagonia (Sicily) has been studied by electron microscopy and comparison between natural and experimental palagonitic layers is made. The behavior of dissolved silica during experiments, and both the structure and the chemical composition of the palagonitic layers, indicate that they form by precipitation of secondary minerals from solution after a total breakdown of the glassy network, i.e., congruent dissolution of the glass. Hence the dissolution equation necessary for thermodynamic modelling of basaltic glass dissolution in seawater at low temperature must be written as a simple stoichiometric process. These experiments indicate that the transformation of glass to palagonitic material is not isovolumetric. Hence it is preferable to use Fe or Ti as conservative elements for chemical budget calculations

  7. Characterization of iron-enriched synthetic basalt for transuranic containment

    International Nuclear Information System (INIS)

    Flinn, J.E.; Henslee, S.P.; Kelsey, P.V.; Tallman, R.L.; Welch, J.M.

    1980-01-01

    In the slagging pyrolytic incineration process, combustibles are burned and noncombustibles, including metals, are oxidized into a molten , an electromelter, where the molten slag, with further processing conducted in a heated tundish, e.g. is allowed to homogenize (within a reasonable time period) and then cast into large, cylindrical metal containers. Analyses of Idaho National Engineering Laboratory waste slags show them similar in composition and appearance to natural basalts, but rich in iron. The electromelt process and the resulting iron-rich castings offer great promise for rendering nuclear waste into a stable form. The process offers great flexibility with regard to both compositional variation of the incoming waste and the high rates at which the waste can be introduced and cast. The cast product, a fine-grained basalt-like material, shows excellent homogeneity with little or no reaction to the steel containment. The preliminary mechanical and chemical durability data show the form to have adequate containment properties for TRU waste. However, work presently underway to improve these properties through additives and controlled cooling cycles has greatly enhanced the durability of the waste form. Furthermore, recent evidence indicates that divalent iron (Fe 2+ ) included in the crystalline phases of granites and basalts imparts a resistance to leaching of uranium and other actinide ions

  8. Fault tree analysis for urban flooding

    NARCIS (Netherlands)

    Ten Veldhuis, J.A.E.; Clemens, F.H.L.R.; Van Gelder, P.H.A.J.M.

    2008-01-01

    Traditional methods to evaluate flood risk mostly focus on storm events as the main cause of flooding. Fault tree analysis is a technique that is able to model all potential causes of flooding and to quantify both the overall probability of flooding and the contributions of all causes of flooding to

  9. Rethinking the relationship between flood risk perception and flood management.

    Science.gov (United States)

    Birkholz, S; Muro, M; Jeffrey, P; Smith, H M

    2014-04-15

    Although flood risk perceptions and their concomitant motivations for behaviour have long been recognised as significant features of community resilience in the face of flooding events, there has, for some time now, been a poorly appreciated fissure in the accompanying literature. Specifically, rationalist and constructivist paradigms in the broader domain of risk perception provide different (though not always conflicting) contexts for interpreting evidence and developing theory. This contribution reviews the major constructs that have been applied to understanding flood risk perceptions and contextualises these within broader conceptual developments around risk perception theory and contemporary thinking around flood risk management. We argue that there is a need to re-examine and re-invigorate flood risk perception research, in a manner that is comprehensively underpinned by more constructivist thinking around flood risk management as well as by developments in broader risk perception research. We draw attention to an historical over-emphasis on the cognitive perceptions of those at risk to the detriment of a richer understanding of a wider range of flood risk perceptions such as those of policy-makers or of tax-payers who live outside flood affected areas as well as the linkages between these perspectives and protective measures such as state-supported flood insurance schemes. Conclusions challenge existing understandings of the relationship between risk perception and flood management, particularly where the latter relates to communication strategies and the extent to which those at risk from flooding feel responsible for taking protective actions. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Flood Risk and Flood hazard maps - Visualisation of hydrological risks

    International Nuclear Information System (INIS)

    Spachinger, Karl; Dorner, Wolfgang; Metzka, Rudolf; Serrhini, Kamal; Fuchs, Sven

    2008-01-01

    Hydrological models are an important basis of flood forecasting and early warning systems. They provide significant data on hydrological risks. In combination with other modelling techniques, such as hydrodynamic models, they can be used to assess the extent and impact of hydrological events. The new European Flood Directive forces all member states to evaluate flood risk on a catchment scale, to compile maps of flood hazard and flood risk for prone areas, and to inform on a local level about these risks. Flood hazard and flood risk maps are important tools to communicate flood risk to different target groups. They provide compiled information to relevant public bodies such as water management authorities, municipalities, or civil protection agencies, but also to the broader public. For almost each section of a river basin, run-off and water levels can be defined based on the likelihood of annual recurrence, using a combination of hydrological and hydrodynamic models, supplemented by an analysis of historical records and mappings. In combination with data related to the vulnerability of a region risk maps can be derived. The project RISKCATCH addressed these issues of hydrological risk and vulnerability assessment focusing on the flood risk management process. Flood hazard maps and flood risk maps were compiled for Austrian and German test sites taking into account existing national and international guidelines. These maps were evaluated by eye-tracking using experimental graphic semiology. Sets of small-scale as well as large-scale risk maps were presented to test persons in order to (1) study reading behaviour as well as understanding and (2) deduce the most attractive components that are essential for target-oriented risk communication. A cognitive survey asking for negative and positive aspects and complexity of each single map complemented the experimental graphic semiology. The results indicate how risk maps can be improved to fit the needs of different user

  11. Towards a Flood Severity Index

    Science.gov (United States)

    Kettner, A.; Chong, A.; Prades, L.; Brakenridge, G. R.; Muir, S.; Amparore, A.; Slayback, D. A.; Poungprom, R.

    2017-12-01

    Flooding is the most common natural hazard worldwide, affecting 21 million people every year. In the immediate moments following a flood event, humanitarian actors like the World Food Program need to make rapid decisions ( 72 hrs) on how to prioritize affected areas impacted by such an event. For other natural disasters like hurricanes/cyclones and earthquakes, there are industry-recognized standards on how the impacted areas are to be classified. Shake maps, quantifying peak ground motion, from for example the US Geological Survey are widely used for assessing earthquakes. Similarly, cyclones are tracked by Joint Typhoon Warning Center (JTWC) and Global Disaster Alert and Coordination System (GDACS) who release storm nodes and tracks (forecasted and actual), with wind buffers and classify the event according to the Saffir-Simpson Hurricane Wind Scale. For floods, the community is usually able to acquire unclassified data of the flood extent as identified from satellite imagery. Most often no water discharge hydrograph is available to classify the event into recurrence intervals simply because there is no gauging station, or the gauging station was unable to record the maximum discharge due to overtopping or flood damage. So, the question remains: How do we methodically turn a flooded area into classified areas of different gradations of impact? Here, we present a first approach towards developing a global applicable flood severity index. The flood severity index is set up such that it considers relatively easily obtainable physical parameters in a short period of time like: flood frequency (relating the current flood to historical events) and magnitude, as well as land cover, slope, and where available pre-event simulated flood depth. The scale includes categories ranging from very minor flooding to catastrophic flooding. We test and evaluate the postulated classification scheme against a set of past flood events. Once a severity category is determined, socio

  12. Strontium isotopic and trace element geochemistry of the saddle mountains and Grande Ronde Basalts of the Columbia River Basalt Group

    International Nuclear Information System (INIS)

    Nelson, D.O.

    1980-01-01

    The Columbia River Basalt (CRB) group displays significant variations in major and trace element and Sr isotopic compositions. These compositions reflect complex and variable origins for the CRB magmas. Among the most varied is the Saddle Mountains Basalt (SMB) in which Sr ratios vary from 0.7078 to 0.7147 +- 0.002. The higher ratios reflect contamination through consistent correlations with major element compositions. Modeling suggests contamination by assimilation of 4.4 to 9.4 wt % of radiogenic crustal rocks. High delta 18 O values (up to +7.68 per mil) support the model. Age and field relations suggest that the contamination flowrocks are not the result of progressive contamination of a single magma, but rather reflect the contamination of independent magmas during this ascent

  13. BENTHIC FORAMINIFERAL BIOSTRATIGRAPHY OF MALATYA OLIGO-MIOCENE SUCCESSION (EASTERN TAURIDS, EASTERN TURKEY

    Directory of Open Access Journals (Sweden)

    Fatma GEDİK

    2015-10-01

    Full Text Available The benthic foraminiferal biostratigraphy of Oligo-Miocene aged Muratlı and Petekkaya formations which crop out over wide regions around Akçadağ town, west of Malatya pro- vince in Eastern Taurids were revealed in this study. Systematical sampling was carried out in measured stratigraphical sections in four locations in order to perform stratigraphical and paleontological investigations. Benthic foraminifera taken from 182 hard rock samples were defined and three biozones were determined as; SBZ 21-22, belonging to Oligocene (Rupe- lian - Early Chattian, SBZ 23 (Late Chattian and SBZ 25 belonging to Lower Miocene in shallow marine deposits in the region. It was stated that the assemblage of planktic forami- nifer and nannoplankton which stratigraphically detected within Chattian - Burdigalian units in the succession most probably indicated Aquitanian age. Besides; Oligo-Miocene transition in the region was approved with this study based on biostratigraphical locations of benthic foraminiferal taxa.

  14. Carbonate pseudotachylite? from a Miocene extensional detachment, W. Cyclades, Greece.

    Science.gov (United States)

    Rice, A. Hugh N.; Grasemann, Bernhard

    2016-04-01

    Most pseudotachylites, both impact- and fault-related, occur in silicate-rich rocks, typically with 'granitoid' compositions. Examples of melting in carbonate rocks, excluding magmatic sources, are restricted to impact-events, except for a carbonate pseudotachylite in the Canalone Fault, S. Italy (Viganò et al. 2011). Another potential example of carbonate pseudotachylite, shown here, comes from the Miocene-aged W. Cycladic Detachment System, in Greece. Top-SSE ductile to brittle movement on this detachment, with a maximum displacement estimated at tens of kilometers, exhumed of HP-rocks. The carbonate pseudotachylite occurs within an 43 mm thick), consists of dark (hematitic) red, ultra-fine grained unlayered carbonate with up to 40x10 mm rather rounded clasts of earlier generations of cataclasite, many with a quartzite composition. These clasts are fractured and partially separated, with a fine red carbonate matrix. No layering of the matrix or clasts is apparent. The clasts become finer and more abundant towards the boundary with Layer B. Layers B and D (~57 & ~20 mm thick) dominantly comprises protocataclasite with greyish quartz fragments separated by a carbonate matrix along narrow fractures. Zone C and E (~23 m & >15 mm thick) comprise pale pink carbonate-dominated rocks with abundant material and may have darker (?reaction) rims. No layering is seen in the pale pink groundmass although this is present in some elongate clasts. All layer boundaries are irregular and no principle slip surfaces have been seen. Injection veins from 1 to 9 mm wide and up to at least 100 mm long derive from the central layer (C), cutting the overall layering at a high angle and branching in several places. These veins contain clasts comparable to those in Layer C. Both thick and thin injection-veins are rimmed by impersistent white calcite suggesting that injection was associated with precipitation of calcite. Whether Layer C (and perhaps E also) is a carbonate pseudotachylite is

  15. Prokaryotic diversity, distribution, and insights into their role in biogeochemical cycling in marine basalts and gabbros

    Science.gov (United States)

    Mason, O. U.; di Meo-Savoie, C. A.; Nakagawa, T.; van Nostrand, J. D.; Rosner, M.; Maruyama, A.; Zhou, J.; Fisk, M. R.; Giovannoni, S. J.

    2008-12-01

    Oceanic crust covers nearly 70% of the Earth's surface, of which, the upper, sediment layer is estimated to harbor substantial microbial biomass. Marine crust, however, extends several kilometers beyond this surficial layer, and includes the basalt and gabbro layers. The microbial diversity in basalts is well characterized, yet metabolic diversity is unknown. To date, the microflora associated with gabbros, including microbial and metabolic diversity has not been reported. In our analyses basaltic and gabbroic endoliths were analyzed using terminal restriction fragment length polymorphism, cloning and sequencing, and microarray analysis of functional genes. Our results suggest that despite nearly identical chemical compositions of basalt and gabbro the associated microflora did not overlap. Basalt samples harbor a surprising diversity of seemingly cosmopolitan microorganisms, some of which appear to be basalt specialists. Conversely, gabbros have a low diversity of endoliths, none of which appear to be specifically adapted to the gabbroic environment. Microarray analysis (GeoChip) was used to assay for functional gene diversity in basalts and gabbros. In basalt genes coding for previously unreported processes such as carbon fixation, methane-oxidation, methanogenesis, and nitrogen fixation were present, suggesting that basalts harbor previously unrecognized metabolic diversity. Similar processes were observed in gabbroic samples, yet metabolic inference from phylogenetic relationships of gabbroic endoliths with other microorganisms, suggests that hydrocarbon oxidation is the prevailing metabolism in this environment. Our analyses revealed that the basalt and gabbro layers harbor microorganisms with the genetic potential to significantly impact biogeochemical cycling in the lithosphere and overlying hydrosphere.

  16. Intensity of the Earth's Magnetic Field over the past 6 million years ; A case study from Basaltic Rocks in East Anatolian

    Science.gov (United States)

    Kaya, Nurcan; Baydemir, Niyazi; Cengiz Cinku, Mualla; Hisarli, Z. Mümtaz; Keskin, Mehmet; Leonhardt, Roman

    2015-04-01

    The aim of this study was to determine the intensity variation of the earth magnetic field by using Miocene and Quaternary basaltic rocks in Eastern Anatolian region. A total of ninety one volcanic rocks at twelve different sites are sampled around the Van region. A modified Thellier method was used to determine paleointensity values. Paleointensity results from five sites were accepted according to our confidence criteria. The paleointensity values from the five reliable sites with normal polarity show relatively low paleointensity values compared to the present field of 47 µT. The total paleointensity field values F are 33.96± 3.54 µT for site VAN5 with an age of 5.5 m.y, 19.98± 6.79 µT for site VAN7 with an age of 4.3 m.y, 26.07 ±8.41 µT for site VAN8 with an age of 0.1 m.y, 29.98 ±1.71 µT for site VAN11 with an age of 0.4 m.y and 31.08 ±2.88 µT for site VAN12 with an age of 5.5 m.y. The average VDMs (Virtual Dipol Moments) correspond to 6.01x10²² Am² for the three Miocene sites and to 5.73x10²² Am² for the Quaternary rocks. Our data is in good coherence to previous studies of similar age ranges.

  17. Probabilistic Flood Defence Assessment Tools

    Directory of Open Access Journals (Sweden)

    Slomp Robert

    2016-01-01

    Full Text Available The WTI2017 project is responsible for the development of flood defence assessment tools for the 3600 km of Dutch primary flood defences, dikes/levees, dunes and hydraulic structures. These tools are necessary, as per January 1st 2017, the new flood risk management policy for the Netherlands will be implemented. Then, the seven decades old design practice (maximum water level methodology of 1958 and two decades old safety standards (and maximum hydraulic load methodology of 1996 will formally be replaced by a more risked based approach for the national policy in flood risk management. The formal flood defence assessment is an important part of this new policy, especially for flood defence managers, since national and regional funding for reinforcement is based on this assessment. This new flood defence policy is based on a maximum allowable probability of flooding. For this, a maximum acceptable individual risk was determined at 1/100 000 per year, this is the probability of life loss of for every protected area in the Netherlands. Safety standards of flood defences were then determined based on this acceptable individual risk. The results were adjusted based on information from cost -benefit analysis, societal risk and large scale societal disruption due to the failure of critical infrastructure e.g. power stations. The resulting riskbased flood defence safety standards range from a 300 to a 100 000 year return period for failure. Two policy studies, WV21 (Safety from floods in the 21st century and VNK-2 (the National Flood Risk in 2010 provided the essential information to determine the new risk based safety standards for flood defences. The WTI2017 project will provide the safety assessment tools based on these new standards and is thus an essential element for the implementation of this policy change. A major issue to be tackled was the development of user-friendly tools, as the new assessment is to be carried out by personnel of the

  18. Temporal clustering of floods in Germany: Do flood-rich and flood-poor periods exist?

    Science.gov (United States)

    Merz, Bruno; Nguyen, Viet Dung; Vorogushyn, Sergiy

    2016-10-01

    The repeated occurrence of exceptional floods within a few years, such as the Rhine floods in 1993 and 1995 and the Elbe and Danube floods in 2002 and 2013, suggests that floods in Central Europe may be organized in flood-rich and flood-poor periods. This hypothesis is studied by testing the significance of temporal clustering in flood occurrence (peak-over-threshold) time series for 68 catchments across Germany for the period 1932-2005. To assess the robustness of the results, different methods are used: Firstly, the index of dispersion, which quantifies the departure from a homogeneous Poisson process, is investigated. Further, the time-variation of the flood occurrence rate is derived by non-parametric kernel implementation and the significance of clustering is evaluated via parametric and non-parametric tests. Although the methods give consistent overall results, the specific results differ considerably. Hence, we recommend applying different methods when investigating flood clustering. For flood estimation and risk management, it is of relevance to understand whether clustering changes with flood severity and time scale. To this end, clustering is assessed for different thresholds and time scales. It is found that the majority of catchments show temporal clustering at the 5% significance level for low thresholds and time scales of one to a few years. However, clustering decreases substantially with increasing threshold and time scale. We hypothesize that flood clustering in Germany is mainly caused by catchment memory effects along with intra- to inter-annual climate variability, and that decadal climate variability plays a minor role.

  19. Integrated stratigraphy and 40Ar/39Ar chronology of early Middle Miocene sediments from DSDP Leg 42A, Site 372 (Western Mediterranean)

    NARCIS (Netherlands)

    Abdul Aziz, H.; di Stefano, A.; Foresi, L. M.; Hilgen, Frederik J.; Iaccarino, S. M.; Kuiper, K. F.; Lirer, F.; Salvatorini, G.; Turco, E.

    2008-01-01

    An integrated magneto-biostratigraphic framework is presented for Middle Miocene sediments of DSDP Site 372 located in the Western Mediterranean. Detailed biostratigraphic analysis shows a nearly complete sequence of early Middle Miocene calcareous plankton bioevents in the Mediterranean, including

  20. Architecture and growth history of a Miocene carbonate platform from 3D seismic reflection data; Luconia province, offshore Sarawak, Malaysia

    NARCIS (Netherlands)

    Zampetti, V.; Schlager, W.; van Konijnenburg, J.H; Everts, A.J.

    2004-01-01

    Using 3D seismic reflection data and wireline logs we reconstruct in detail the architecture and growth history of a Miocene carbonate platform in the Luconia province, offshore Sarawak, Malaysia. Platform growth started in the Late Oligocene to Early Miocene, by coalescence of isolated patch reefs.

  1. Eocene and miocene rocks off the northeastern coast of the United States

    Science.gov (United States)

    Gibson, T.G.

    1965-01-01

    A grab sample from a depth of 1675 m at a point south of Cape Cod contains early Eocene planktonic Foraminifera and is correlated with the Globorotalia rex zone of Trinidad. The assemblage indicates a depth comparable to that existing today. Regional relations suggest that the Cretaceous and Eocene deposits deepen to the west toward New Jersey. Two mollusk-bearing blocks dredged from the northern side of Georges Bank are correlative with the Miocene Yorktown Formation. Rocks from two other stations are probably Miocene. Benthonic Foraminifera in one sample indicate deposition in cool temperate waters of less than 60 m depth. ?? 1965.

  2. Reserve Special Flood Hazard Areas (SFHA)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This vector dataset depicts the 1% annual flood boundary (otherwise known as special flood hazard area or 100 year flood boundary) for its specified area. The data...

  3. Elephant Butte Special Flood Hazard Areas (SFHA)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This vector dataset depicts the 1% annual flood boundary (otherwise known as special flood hazard area or 100 year flood boundary) for its specified area. The data...

  4. The Aqueduct Global Flood Analyzer

    Science.gov (United States)

    Iceland, Charles

    2015-04-01

    As population growth and economic growth take place, and as climate change accelerates, many regions across the globe are finding themselves increasingly vulnerable to flooding. A recent OECD study of the exposure of the world's large port cities to coastal flooding found that 40 million people were exposed to a 1 in 100 year coastal flood event in 2005, and the total value of exposed assets was about US 3,000 billion, or 5% of global GDP. By the 2070s, those numbers were estimated to increase to 150 million people and US 35,000 billion, or roughly 9% of projected global GDP. Impoverished people in developing countries are particularly at risk because they often live in flood-prone areas and lack the resources to respond. WRI and its Dutch partners - Deltares, IVM-VU University Amsterdam, Utrecht University, and PBL Netherlands Environmental Assessment Agency - are in the initial stages of developing a robust set of river flood and coastal storm surge risk measures that show the extent of flooding under a variety of scenarios (both current and future), together with the projected human and economic impacts of these flood scenarios. These flood risk data and information will be accessible via an online, easy-to-use Aqueduct Global Flood Analyzer. We will also investigate the viability, benefits, and costs of a wide array of flood risk reduction measures that could be implemented in a variety of geographic and socio-economic settings. Together, the activities we propose have the potential for saving hundreds of thousands of lives and strengthening the resiliency and security of many millions more, especially those who are most vulnerable. Mr. Iceland will present Version 1.0 of the Aqueduct Global Flood Analyzer and provide a preview of additional elements of the Analyzer to be released in the coming years.

  5. Flood Risk, Flood Mitigation, and Location Choice: Evaluating the National Flood Insurance Program's Community Rating System.

    Science.gov (United States)

    Fan, Qin; Davlasheridze, Meri

    2016-06-01

    Climate change is expected to worsen the negative effects of natural disasters like floods. The negative impacts, however, can be mitigated by individuals' adjustments through migration and relocation behaviors. Previous literature has identified flood risk as one significant driver in relocation decisions, but no prior study examines the effect of the National Flood Insurance Program's voluntary program-the Community Rating System (CRS)-on residential location choice. This article fills this gap and tests the hypothesis that flood risk and the CRS-creditable flood control activities affect residential location choices. We employ a two-stage sorting model to empirically estimate the effects. In the first stage, individuals' risk perception and preference heterogeneity for the CRS activities are considered, while mean effects of flood risk and the CRS activities are estimated in the second stage. We then estimate heterogeneous marginal willingness to pay (WTP) for the CRS activities by category. Results show that age, ethnicity and race, educational attainment, and prior exposure to risk explain risk perception. We find significant values for the CRS-creditable mitigation activities, which provides empirical evidence for the benefits associated with the program. The marginal WTP for an additional credit point earned for public information activities, including hazard disclosure, is found to be the highest. Results also suggest that water amenities dominate flood risk. Thus, high amenity values may increase exposure to flood risk, and flood mitigation projects should be strategized in coastal regions accordingly. © 2015 Society for Risk Analysis.

  6. Seismic sequence stratigraphy of Miocene deposits related to eustatic, tectonic and climatic events, Cap Bon Peninsula, northeastern Tunisia

    Science.gov (United States)

    Gharsalli, Ramzi; Zouaghi, Taher; Soussi, Mohamed; Chebbi, Riadh; Khomsi, Sami; Bédir, Mourad

    2013-09-01

    The Cap Bon Peninsula, belonging to northeastern Tunisia, is located in the Maghrebian Alpine foreland and in the North of the Pelagian block. By its paleoposition, during the Cenozoic, in the edge of the southern Tethyan margin, this peninsula constitutes a geological entity that fossilized the eustatic, tectonic and climatic interactions. Surface and subsurface study carried out in the Cap Bon onshore area and surrounding offshore of Hammamet interests the Miocene deposits from the Langhian-to-Messinian interval time. Related to the basin and the platform positions, sequence and seismic stratigraphy studies have been conducted to identify seven third-order seismic sequences in subsurface (SM1-SM7), six depositional sequences on the Zinnia-1 petroleum well (SDM1-SDM6), and five depositional sequences on the El Oudiane section of the Jebel Abderrahmane (SDM1-SDM5). Each sequence shows a succession of high-frequency systems tract and parasequences. These sequences are separated by remarkable sequence boundaries and maximum flooding surfaces (SB and MFS) that have been correlated to the eustatic cycles and supercycles of the Global Sea Level Chart of Haq et al. (1987). The sequences have been also correlated with Sequence Chronostratigraphic Chart of Hardenbol et al. (1998), related to European basins, allows us to arise some major differences in number and in size. The major discontinuities, which limit the sequences resulted from the interplay between tectonic and climatic phenomena. It thus appears very judicious to bring back these chronological surfaces to eustatic and/or local tectonic activity and global eustatic and climatic controls.

  7. Floods in the Saguenay

    International Nuclear Information System (INIS)

    Martel, R.; Michaud, E.; Tousignant, P.M.

    1997-01-01

    Footage of a natural disaster that occurred between July 20 and 25 1996, in the Saguenay region of Quebec was documented. A heavy downpour of rain raised the water level of the Kenogami Lake reservoir beyond its capacity. This created huge pressure on its dam that upset the fragile balance between nature and rock. The dam raptured, resulting in a flood of previously unseen proportions. The Riviere au Sable in Jonquiere became an overwhelming body of water. The video showed how the shores of the river were eroded and how apartment buildings were engulfed by the torrent of water. A newly constructed electricity power plant had to be decommissioned, roads were washed away and entire neighborhoods were devastated. The devastation suffered by the cities of Chicoutimi, Jonquiere, Ville de la Baie, Ferland-Boileau, and L'Anse St-Jean was recorded. Thousands of victims of the disaster were evacuated with the help of the Canadian Armed Forces. Some of the work of reconstruction, begun even before the total retreat of the flood, involved restoration of roads, bridges and communication networks, was also shown

  8. UTILIZATION OF BASALT FIBERS AS A RAW MATERIAL FOR CLAY CERAMIC PRODUCTION

    Directory of Open Access Journals (Sweden)

    Supawan Vichaphund

    2016-03-01

    Full Text Available This research aimed to investigate the possibility of utilization basalt fibers as a raw material for ceramic production. Both quartz and feldspar were replaced partially or entirely by basalt fiber in the range of 10-25 wt%. The mixture of ceramic powders and basalt fibers were uniaxially pressed and sintered at temperatures between 1000 and 1200°C for 1 h. The substitution of basalt fibers in ceramic compositions demonstrated the positive effect on the physical and mechanical properties. The addition of basalt fibers in an appropriate amount enhance the densification and reduce sintering temperature of clay-based ceramics (CB-0 from 1200 to 1150°C. The highest density and strength were 2.40 g/cm³ and 116 MPa, respectively, when replacing feldspar and quartz with basalt up to 20 wt% (CB-20 and sintering at 1150°C.

  9. Flood risk management in Italy

    DEFF Research Database (Denmark)

    Mysiak, J.; Testella, F.; Bonaiuto, M.

    2013-01-01

    Italy's recent history is punctuated with devastating flood disasters claiming high death toll and causing vast but underestimated economic, social and environmental damage. The responses to major flood and landslide disasters such as the Polesine (1951), Vajont (1963), Firenze (1966), Valtelina...

  10. Internal flooding analyses results of Slovak NPPs

    International Nuclear Information System (INIS)

    Sopira, Vladimir

    2000-01-01

    The assessment of the flood risk was the objective of the internal flooding analysis for NPPs Bohunice V1, V2 and Mochovce. All important flooding sources were identified. The rooms containing safety important components were analyzed from the point of view of: Integrity of flood boundaries; Capability for drainage; Flood signalisation; Flood localization and liquidation; Vulnerability of safety system component. The redundancies of safety systems are located mostly separately and no flood can endanger more than single train. It can be concluded that NPPs with WWER-440 are very safe against the flooding initiating event

  11. Flow in the western Mediterranean shallow mantle: Insights from xenoliths in Pliocene alkali basalts from SE Iberia (eastern Betics, Spain)

    Science.gov (United States)

    Hidas, Károly; Konc, Zoltán.; Garrido, Carlos J.; Tommasi, Andréa.; Vauchez, Alain; Padrón-Navarta, José Alberto; Marchesi, Claudio; Booth-Rea, Guillermo; Acosta-Vigil, Antonio; Szabó, Csaba; Varas-Reus, María. Isabel; Gervilla, Fernando

    2016-11-01

    Mantle xenoliths in Pliocene alkali basalts of the eastern Betics (SE Iberia, Spain) are spinel ± plagioclase lherzolite, with minor harzburgite and wehrlite, displaying porphyroclastic or equigranular textures. Equigranular peridotites have olivine crystal preferred orientation (CPO) patterns similar to those of porphyroclastic xenoliths but slightly more dispersed. Olivine CPO shows [100]-fiber patterns characterized by strong alignment of [100]-axes subparallel to the stretching lineation and a girdle distribution of [010]-axes normal to it. This pattern is consistent with simple shear or transtensional deformation accommodated by dislocation creep. One xenolith provides evidence for synkinematic reactive percolation of subduction-related Si-rich melts/fluids that resulted in oriented crystallization of orthopyroxene. Despite a seemingly undeformed microstructure, the CPO in orthopyroxenite veins in composite xenoliths is identical to those of pyroxenes in the host peridotite, suggesting late-kinematic crystallization. Based on these observations, we propose that the annealing producing the equigranular microstructures was triggered by melt percolation in the shallow subcontinental lithospheric mantle coeval to the late Neogene formation of veins in composite xenoliths. Calculated seismic properties are characterized by fast propagation of P waves and polarization of fast S waves parallel to olivine [100]-axis (stretching lineation). These data are compatible with present-day seismic anisotropy observations in SE Iberia if the foliations in the lithospheric mantle are steeply dipping and lineations are subhorizontal with ENE strike, implying dominantly horizontal mantle flow in the ENE-WSW direction within vertical planes, that is, subparallel to the paleo-Iberian margin. The measured anisotropy could thus reflect a lithospheric fabric due to strike-slip deformation in the late Miocene in the context of WSW tearing of the subducted south Iberian margin

  12. A modeling study of contaminant transport resulting from flooding of Pit 9 at the Radioactive Waste Management Complex, Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Magnuson, S.O.; Sondrup, A.J.

    1992-09-01

    A simulation study was conducted to determine if dissolved-phase transport due to flooding is a viable mechanism for explaining the presence of radionuclides in sedimentary interbeds below the Radioactive Waste Management Complex. In particular, the study focused on 241 Am migration due to flooding of Pit 9 in 1969. A kinetically-controlled source term model was used to estimate the mass of 241 Am that leached as a function of a variable surface infiltration rate. This mass release rate was then used in a numerical simulation of unsaturated flow and transport to estimate the advance due to flooding of the 241 Am front down towards the 110 ft interbed. The simulation included the effect of fractures by superimposing them onto elements that represented the basalt matrix. For the base case, hydraulic and transport parameters were assigned using the best available data. The advance of the 241 Am front due to flooding for this case was minimal, on the order of a few meters. This was due to the strong tendency for 241 Am to sorb onto both basalts and sediments. In addition to the base case simulation, a parametric sensitivity study was conducted which tested the effect of sorption in the fractures, in the kinetic source term, and in the basalt matrix. Of these, the only case which resulted in significant transport was when there was no sorption in the basalt matrix. The indication being that other processes such as transport by radiocolloids or organic complexation may have contributed. However, caution is advised in interpreting these results due to approximations in the numerical method that was used incorporate fractures into the simulation. The approximations are a result of fracture apertures being significantly smaller than the elements over which they are superimposed. The sensitivity of the 241 Am advance to the assumed hydraulic conductivity for the fractures was also tested

  13. Methods of simulating low redox potential (Eh) for a basalt repository

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1983-01-01

    Basalt groundwaters have inherently low redox potentials, approximately -0.4V, which can be measured with platinum electrodes, but are difficult to reproduce during leaching experiments. In the presence of deionized water, crushed basalt reaches the measured Eh-pH values of a basalt repository. Other waste package components, such as iron, will interact with groundwater in different ways under oxic or anoxic conditions since the presence of any redox active solid will affect the groundwater Eh. 26 references, 4 figures

  14. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed

  15. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.

  16. The hardness of synthetic products obtained from cooled and crystallized basaltic melts (in Romanian)

    OpenAIRE

    Daniela Ogrean

    2001-01-01

    The Hardness of Synthetic Products Obtained from Cooled and Crystallized Basaltic Melts. Hardness is one of the main properties of the products obtained from cooled and crystallized basaltic melts under a controlled thermal regime. It influences the abrasion tear resistance of the resulted material. The microhardness measurements on the samples (bricks, boards, gutters, armour plates, tubes) indicated Vickers hardness value between 757–926 for the materials obtained from Şanovita basalts (Tim...

  17. Developing a Malaysia flood model

    Science.gov (United States)

    Haseldine, Lucy; Baxter, Stephen; Wheeler, Phil; Thomson, Tina

    2014-05-01

    Faced with growing exposures in Malaysia, insurers have a need for models to help them assess their exposure to flood losses. The need for an improved management of flood risks has been further highlighted by the 2011 floods in Thailand and recent events in Malaysia. The increasing demand for loss accumulation tools in Malaysia has lead to the development of the first nationwide probabilistic Malaysia flood model, which we present here. The model is multi-peril, including river flooding for thousands of kilometres of river and rainfall-driven surface water flooding in major cities, which may cause losses equivalent to river flood in some high-density urban areas. The underlying hazard maps are based on a 30m digital surface model (DSM) and 1D/2D hydraulic modelling in JFlow and RFlow. Key mitigation schemes such as the SMART tunnel and drainage capacities are also considered in the model. The probabilistic element of the model is driven by a stochastic event set based on rainfall data, hence enabling per-event and annual figures to be calculated for a specific insurance portfolio and a range of return periods. Losses are estimated via depth-damage vulnerability functions which link the insured damage to water depths for different property types in Malaysia. The model provides a unique insight into Malaysian flood risk profiles and provides insurers with return period estimates of flood damage and loss to property portfolios through loss exceedance curve outputs. It has been successfully validated against historic flood events in Malaysia and is now being successfully used by insurance companies in the Malaysian market to obtain reinsurance cover.

  18. Rb-Sr and Sm-Nd chronology and genealogy of mare basalts from the Sea of Tranquility

    Science.gov (United States)

    Papanastassiou, D. A.; Depaolo, D. J.; Wasserburg, G. J.

    1977-01-01

    Rb-Sr and Sm-Nd ages of two Apollo 11 mare basalts, high-K basalt 10072 and low-K basalt 10062, are reported. Rb-Sr, Sm-Nd, and Ar-40-Ar-39 ages are in good agreement and indicate an extensive time interval for filling of the Sea of Tranquility, presumably by thin lava flows, in agreement with similar observations for the Ocean of Storms. Initial Sr and Nd isotopic compositions on Apollo 11 basalts reveal at least two parent sources producing basalts. The Sm-Nd isotopic data demonstrate that low-K and high-Ti basalts from Apollo 11 and 17 derived from distinct reservoirs, while low-Ti Apollo 15 mare basalt sources have Sm/Nd similar to the sources of Apollo 11 basalts. Groupings of mare basalt based on Ti content and on isotopic data do not coincide.

  19. Hydraulics of outburst floods spilling over a steep-walled canyon: Implications for paleo-discharges on Mars

    Science.gov (United States)

    Lapotre, Mathieu; Lamb, Michael

    2013-04-01

    Canyons carved by outburst floods are common landforms on Earth and Mars. These canyons are generally found in fractured basalts and jointed sedimentary rocks. Flood-carved canyons commonly have steep headwalls and a roughly constant width, and are often thought to have formed from upstream headwall propagation due to waterfall erosion. Because morphology is readily available from satellite imagery, these canyons offer a unique opportunity to quantify the discharge of rare, catastrophic paleo-floods on Earth and Mars. However, mechanistic relationships that relate canyon size to flood discharge have yet to be developed. We propose that the width of a canyon headwall in fractured rock is set by the spatial distribution of erosion around the rim of the canyon, which is controlled by the distribution of shear stresses induced by the overflowing water as it is focused into the canyon head. We test this hypothesis by performing a series of numerical simulations of flood-water focusing using ANUGA Hydro, a 2D-depth averaged, fully turbulent, hydraulic numerical modeling suite allowing for Froude-number transitions. The numerical simulations were designed to explore five dimensionless variables: the aspect ratio of the canyon (length normalized by width), the canyon width to flood-water width ratio, the canyon width to normal-flow depth ratio, the Froude number, and the topographic gradient upstream of the canyon. Preliminary results show that flow focusing leads to increased shear stresses at the canyon head compared to the sides of the canyon for subcritical floods and higher canyon aspect ratios. This suggests that proto-canyons start growing from a topographic defect in all directions until they reach a critical length for the side walls to dry. Once this critical length is attained, canyons focus most of the flood waters into their heads, and propagate upstream only, maintaining roughly constant widths. Preliminary results suggest that canyon width may be used to

  20. A Brillouin scattering study of hydrous basaltic glasses: the effect of H2O on their elastic behavior and implications for the densities of basaltic melts

    Science.gov (United States)

    Wu, Lei; Yang, De-Bin; Liu, Jun-Xiu; Hu, Bo; Xie, Hong-Sen; Li, Fang-Fei; Yu, Yang; Xu, Wen-Liang; Gao, Chun-Xiao

    2017-06-01

    Hydrous basalt glasses with water contents of 0-6.82% were synthesized using a multi-anvil press at 1.0-2.0 GPa and 1200-1400 °C. The starting materials were natural Mesozoic basalts from the eastern North China Craton (NCC). Their sound velocities and elastic properties were measured by Brillouin scattering spectroscopy. The longitudinal ( V P) and shear ( V S) wave velocities decreased with increasing water content. Increasing the synthesis pressure resulted in the glass becoming denser, and finally led to an increase in V P. As the degree of depolymerization increased, the V P, V S, and shear and bulk moduli of the hydrous basalt glasses decreased, whereas the adiabatic compressibility increased. The partial molar volumes of water (ν) under ambient conditions were independent of composition, having values of 11.6 ± 0.8, 10.9 ± 0.6 and 11.5 ± 0.5 cm3/mol for the FX (Feixian), FW (Fuxin), and SHT (Sihetun) basalt glasses, respectively. However, the {{V}_{{{{H}}_{{2}}}{O}}} values measured at elevated temperatures and pressures are increasing with increasing temperature or decreasing pressure. The contrasting densities of these hydrous basalt melts with those previously reported for mid-ocean ridge basalt and preliminary reference Earth model data indicate that hydrous basalt melts may not maintain gravitational stability at the base of the upper mantle.

  1. Texas floods of 1940

    Science.gov (United States)

    Breeding, Seth D.

    1948-01-01

    Floods occurred in Texas during, June, July, and November 1940 that exceeded known stages on many small streams and at a few places on the larger streams. Stages at several stream-gaging stations exceeded the maximum known at those places since the collection of daily records began. A storm, haying its axis generally on a north-south line from Cameron to Victoria and extending across the Brazos, Colorado, Lavaca, and Guadalupe River Basins, caused heavy rainfall over a large part of south-central Texas. The maximum recorded rain of 22.7 inches for the 2-day period June 29-30 occurred at Engle. Of this amount, 17.5 inches fell in the 12-hour period between 8 p.m. June 29, and 8 a.m. June 30. Light rains fell at a number of places on June 28, and additional light rains fell at many places within the area from July 1 to 4. During the period June 28 to July 4 more than 20 inches of rain fell over an area of 300 square miles, more than 15 inches over 1,920 square miles, and more than 10 inches over 5,100 square miles. The average annual rainfall for the area experiencing the heaviest rainfall during this storm is about 35 inches. Farming is largely confined to the fertile flood plains in much of the area subjected to the record-breaking floods in June and July. Therefore these floods, coming at the height of the growing season, caused severe losses to crops. Much damage was done also to highways and railways. The city of Hallettsville suffered the greatest damage of any urban area. The Lavaca River at that place reached a stage 8 feet higher than ever known before, drowned several people, destroyed many homes, and submerged almost the entire business district. The maximum discharge there was 93,100 second-feet from a drainage area of 101 square miles. Dry Creek near Smithville produced a maximum discharge of 1,879 second-feet from an area of 1.48 square miles and a runoff of 11.3 inches in a 2-day period from a rainfall of 19.5 inches. The area in the Colorado River

  2. Geology of the Sabie River Basalt Formation in the Southern Kruger National Park

    Directory of Open Access Journals (Sweden)

    R.J. Sweeney

    1986-11-01

    Full Text Available The Sabie River Basalt Formation (SRBF in the central Lebombo is a virtually continuous sequence of basaltic lavas some 2 500 m thick that was erupted 200 - 179 Ma ago. Flows are dominantly pahoehoe in character and vary from 2 m to 20 m in thickness. Dolerite dykes cross-cutting the basalt sequence probably represent feeders to this considerable volcanic event. Volcanological features observed within the SRBF are described. Two chemically distinct basaltic magma types are recognised, the simultaneous eruption of which presents an intriguing geochemical problem as to their origins.

  3. Radiation shielding properties of a novel cement–basalt mixture for nuclear energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Ipbüker, Cagatay; Nulk, Helena; Gulik, Volodymyr [University of Tartu, Institute of Physics (Estonia); Biland, Alex [HHK Technologies, Houston (United States); Tkaczyk, Alan Henry, E-mail: alan@ut.ee [University of Tartu, Institute of Physics (Estonia)

    2015-04-01

    Highlights: • Basalt fiber is a relatively cheap material that can be used as reinforcement. • Gamma-ray attenuation remains relatively stable with addition of basalt fiber. • Neutron attenuation remains relatively stable with addition of basalt fiber. • Cement–basalt mixture has a good potential for use in nuclear energy applications. - Abstract: The radiation shielding properties of a new proposed building material, a novel cement–basalt fiber mixture (CBM), are investigated. The authors analyze the possibility of this material to be a viable substitute to outgoing materials in nuclear energy applications, which will lead to a further sustained development of nuclear energy in the future. This computational study involves four types of concrete with various amounts of basalt fiber in them. The gamma-ray shielding characteristics of proposed CBM material are investigated with the help of WinXCom program, whereas the neutron shielding characteristics are computed by the Serpent code. For gamma-ray shielding, we find that the attenuation coefficients of concretes with basalt fibers are not notably influenced by the addition of fibers. For neutron shielding, additional basalt fiber in mixture presents negligible effect on neutron radiation shielding. With respect to radiation shielding, it can be concluded that basalt fibers have good potential as an addition to heavyweight concrete for nuclear energy applications.

  4. Basalt fiber manufacturing technology and the possibility of its use in dentistry

    International Nuclear Information System (INIS)

    Karavaeva, E; Rogozhnikov, A; Nikitin, V; Cherepennikov, Yu; Lysakov, A

    2015-01-01

    The article touches upon the technology of basalt fiber manufacturing and prospects of its use in dental practice. Two kinds of construction using basalt fiber have been proposed. The first one is a splinting construction for mobile teeth and the second one is the reinforced base for removable plate-denture. The work presents the results of the investigation of physical and mechanical properties of the constructions based on basalt fiber. It also describes the aspects of biomechanical modeling of such constructions in the ANSYS software package. The results of the investigation have proved that applying constructions using basalt fiber is highly promising for prosthetic dentistry practice. (paper)

  5. Basalt Fiber for Volcanic Slag Lightweight Aggregate Concrete Research on the Impact of Performance

    Science.gov (United States)

    Xiao, Li-guang; Li, Gen-zhuang

    2018-03-01

    In order to study the effect of basalt fiber on the mechanical properties and durability of volcanic slag lightweight aggregate concrete, the experimental study on the flexural strength, compressive strength and freeze-thaw resistance of volcanic slag concrete with different basalt fiber content were carried out, the basalt fiber was surface treated with NaOH and water glass, the results show that the surface treatment of basalt fiber can significantly improve the mechanical properties, durability and other properties of volcanic slag lightweight aggregate concrete.

  6. Basalt fiber manufacturing technology and the possibility of its use in dentistry

    Science.gov (United States)

    Karavaeva, E.; Rogozhnikov, A.; Nikitin, V.; Cherepennikov, Yu; Lysakov, A.

    2015-11-01

    The article touches upon the technology of basalt fiber manufacturing and prospects of its use in dental practice. Two kinds of construction using basalt fiber have been proposed. The first one is a splinting construction for mobile teeth and the second one is the reinforced base for removable plate-denture. The work presents the results of the investigation of physical and mechanical properties of the constructions based on basalt fiber. It also describes the aspects of biomechanical modeling of such constructions in the ANSYS software package. The results of the investigation have proved that applying constructions using basalt fiber is highly promising for prosthetic dentistry practice.

  7. Radiation shielding properties of a novel cement–basalt mixture for nuclear energy applications

    International Nuclear Information System (INIS)

    Ipbüker, Cagatay; Nulk, Helena; Gulik, Volodymyr; Biland, Alex; Tkaczyk, Alan Henry

    2015-01-01

    Highlights: • Basalt fiber is a relatively cheap material that can be used as reinforcement. • Gamma-ray attenuation remains relatively stable with addition of basalt fiber. • Neutron attenuation remains relatively stable with addition of basalt fiber. • Cement–basalt mixture has a good potential for use in nuclear energy applications. - Abstract: The radiation shielding properties of a new proposed building material, a novel cement–basalt fiber mixture (CBM), are investigated. The authors analyze the possibility of this material to be a viable substitute to outgoing materials in nuclear energy applications, which will lead to a further sustained development of nuclear energy in the future. This computational study involves four types of concrete with various amounts of basalt fiber in them. The gamma-ray shielding characteristics of proposed CBM material are investigated with the help of WinXCom program, whereas the neutron shielding characteristics are computed by the Serpent code. For gamma-ray shielding, we find that the attenuation coefficients of concretes with basalt fibers are not notably influenced by the addition of fibers. For neutron shielding, additional basalt fiber in mixture presents negligible effect on neutron radiation shielding. With respect to radiation shielding, it can be concluded that basalt fibers have good potential as an addition to heavyweight concrete for nuclear energy applications

  8. Nuclear waste repository in basalt: preconceptual design guidelines

    International Nuclear Information System (INIS)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation

  9. Nuclear waste repository in basalt: preconceptual design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation.

  10. Improving Gas Flooding Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Reid Grigg; Robert Svec; Zheng Zeng; Alexander Mikhalin; Yi Lin; Guoqiang Yin; Solomon Ampir; Rashid Kassim

    2008-03-31

    This study focuses on laboratory studies with related analytical and numerical models, as well as work with operators for field tests to enhance our understanding of and capabilities for more efficient enhanced oil recovery (EOR). Much of the work has been performed at reservoir conditions. This includes a bubble chamber and several core flood apparatus developed or modified to measure interfacial tension (IFT), critical micelle concentration (CMC), foam durability, surfactant sorption at reservoir conditions, and pressure and temperature effects on foam systems.Carbon dioxide and N{sub 2} systems have been considered, under both miscible and immiscible conditions. The injection of CO2 into brine-saturated sandstone and carbonate core results in brine saturation reduction in the range of 62 to 82% brine in the tests presented in this paper. In each test, over 90% of the reduction occurred with less than 0.5 PV of CO{sub 2} injected, with very little additional brine production after 0.5 PV of CO{sub 2} injected. Adsorption of all considered surfactant is a significant problem. Most of the effect is reversible, but the amount required for foaming is large in terms of volume and cost for all considered surfactants. Some foams increase resistance to the value beyond what is practical in the reservoir. Sandstone, limestone, and dolomite core samples were tested. Dissolution of reservoir rock and/or cement, especially carbonates, under acid conditions of CO2 injection is a potential problem in CO2 injection into geological formations. Another potential change in reservoir injectivity and productivity will be the precipitation of dissolved carbonates as the brine flows and pressure decreases. The results of this report provide methods for determining surfactant sorption and can be used to aid in the determination of surfactant requirements for reservoir use in a CO{sub 2}-foam flood for mobility control. It also provides data to be used to determine rock permeability

  11. Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

    International Nuclear Information System (INIS)

    Bennecke, W.M.

    1996-10-01

    A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well

  12. Sentinel Gap basalt reacted in a temperature gradient

    International Nuclear Information System (INIS)

    Charles, R.W.; Bayhurst, G.K.

    1983-01-01

    Six basalt prisms were reacted in a controlled temperature gradient hydrothermal circulation system for two months. The prisms were centered at 72, 119, 161, 209, 270, and 310 0 C. Total pressure was 1/3 kbar. All prisms showed large weight loss: 5.5% to 14.9%. The matrix micropegmatite and natural nontronitic alteration reacted readily to clays at all temperatures. The first four prisms were coated with a calcium smectite, and the last two prisms were covered with discrete patches of potassium-rich phengite and alkali feldspar. The results indicated that clays may act as adsorbers of various ions

  13. Sentinel Gap basalt reacted in a temperature gradient

    International Nuclear Information System (INIS)

    Charles, R.W.; Bayhurst, G.K.

    1982-01-01

    Six basalt prisms were reacted in a controlled temperature gradient hydrothermal circulation system for two months. The prisms are centered at 72, 119, 161, 209, 270, and 310 0 C. Total pressure is 1/3 kbar. All prisms show large weight loss: 5.5% to 14.9%. The matrix micropegmatite and natural nontronitic alteration readily reacts to clays at all temperatures. The first four prisms are coated with a Ca-smectite while the last two prisms are covered with discrete patches of K rich phengite and alkali feldspar. The clays may act as adsorbers of various ions

  14. Environmental issue identification for the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    Carrell, D.J.; Jones, K.A.

    1980-04-01

    A preliminary evaluation of environmental issues is provided in this report. It contains summary of the thought process that was used during the area characterization studies for a geological repository for high-level radioactive wastes. Environmental issues are discussed separately for construction, operation, and long term isolation aspects of a repository in basalt. During construction the primary environmental concerns are public perception and water resources; intermediate concerns are air quality, ecosystems, physical resources, and cultural and social resources. During operation, the primary environmental issues concern the transport of radioactive materials and physical resources. Long term environmental issues envolve water resources and borehole plugging

  15. Basalt Waste Isolation Project exploratory shaft site: Final reclamation report

    International Nuclear Information System (INIS)

    Brandt, C.A.; Rickard, W.H. Jr.

    1990-06-01

    The restoration of areas disturbed by activities of the Basalt Waste Isolation Project (BWIP) constitutes a unique operation at the US Department of Energy's (DOE) Hanford Site, both from the standpoint of restoration objectives and the time frame for accomplishing these objectives. The BWIP reclamation program comprises three separate projects: borehole reclamation, Near Surface Test Facility (NSTF) reclamation, and Exploratory Shaft Facility (ESF) reclamation. The main focus of this report is on determining the success of the revegetation effort 1 year after work was completed. This report also provides a brief overview of the ESF reclamation program. 21 refs., 7 figs., 14 tabs

  16. Penetration of molten core materials into basaltic and limestone concrete

    International Nuclear Information System (INIS)

    Sutherland, H.J.

    1978-01-01

    In conjunction with the small-scale, melt-concrete interaction tests being conducted at Sandia Laboratories, an acoustic technique has been used to monitor the penetration of molten core materials into basaltic and limestone concrete. Real time plots of the position of the melt/concrete interface have been obtained, and they illustrate that the initial penetration rate of the melt may be of the order of 80 mm/min. Phenomena deduced by the technique include a non-wetted melt/concrete interface

  17. Hydrologic bibliography of the Columbia River basalts in Washington

    International Nuclear Information System (INIS)

    Tanaka, H.H.; Wildrick, L.

    1978-07-01

    This bibliography is part of the hydrologic data compilation effort of the Columbia Plateau Hydrology Study, Rockwell Hanford Operations' Waste Isolation Program. It includes references on both surface and subsurface hydrology directly or indirectly related to the Washington State portion of the Columbia River basalts. A comprehensive, annotated bibliography of the Pasco Basin (including the Hanford site) hydrology has been prepared for Rockwell Hanford Operations under the Pasco Basin Hydrology Study. In order to avoid unnecessary duplication, no effort was made to include a complete list of bibliographic references on Hanford in this volume

  18. Structural Analysis of Basalt Fiber Reinforced Plastic Wind Turbine Blade

    Directory of Open Access Journals (Sweden)

    Mengal Ali Nawaz

    2014-07-01

    Full Text Available In this study, Basalt fiber reinforced plastic (BFRP wind turbine blade was analyzed and compared with Glass fiber reinforced plastic blade (GFRP. Finite element analysis (FEA of blade was carried out using ANSYS. Data for FEA was obtained by using rule of mixture. The shell element in ANSYS was used to simulate the wind turbine blade and to conduct its strength analysis. The structural analysis and comparison of blade deformations proved that BFRP wind turbine blade has better strength compared to GFRP wind turbine blade.

  19. Melt density and the average composition of basalt

    Science.gov (United States)

    Stolper, E.; Walker, D.

    1980-01-01

    Densities of residual liquids produced by low pressure fractionation of olivine-rich melts pass through a minimum when pyroxene and plagioclase joint the crystallization sequence. The observation that erupted basalt compositions cluster around the degree of fractionation from picritic liquids corresponding to the density minimum in the liquid line of descent may thus suggest that the earth's crust imposes a density fiber on the liquids that pass through it, favoring the eruption of the light liquids at the density minimum over the eruption of denser more fractionated and less fractionated liquids.

  20. Response of Mediterranean circulation to Miocene shoaling and closure of the Indian Gateway : A model study

    NARCIS (Netherlands)

    De La Vara, Alba; Meijer, Paul

    2016-01-01

    In this regional ocean model study, we explore the effect of the Early to Middle Miocene shoaling and closure of the Indian Gateway on Mediterranean circulation and its exchange with the adjacent oceans. For this we use the regional ocean circulation model "sbPOM" and a collection of bathymetries

  1. The development of the Amazonian mega-wetland (Miocene; Brazil, Colombia, Peru, Bolivia)

    NARCIS (Netherlands)

    Hoorn, C.; Wesselingh, F.P.; Hovikoski, J.; Guerrero, J.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The scenery of Western Amazonia once consisted of fluvial systems that originated on the Amazonian Craton and were directed towards the sub-Andean zone and the Caribbean. In the course of the Early Miocene these fluvial systems were largely replaced by lakes, swamps, tidal channels and marginal

  2. The Middle Miocene Climate Transition in the Central Mediterranean. Geologica Ultraiectina (326)

    NARCIS (Netherlands)

    Mourik, A.A.|info:eu-repo/dai/nl/304849383

    2010-01-01

    The Middle Miocene Climate Transition (~15-13.7 Ma) is one of the major steps in Cenozoic climate evolution. The rapid expansion of the East Antarctic Ice Sheet at ~13.9 – 13.7 Ma caused important climate changes on a global scale. The aim of this PhD research has been to study the effects of the

  3. Fish remains from Miocene beds of Višnja vas near Vojnik, Slovenia

    Directory of Open Access Journals (Sweden)

    Aleš Šoster

    2013-06-01

    Full Text Available This paper discusses fossil teeth of sharks (Elasmobranchii, Neoselachii and porgies (Teleostei, Sparidae fromthe Miocene glauconite sandstones of Vi{nja vas near Vojnik. The remains of fish teeth, mostly tooth crowns, belongto cartilaginous fishes of the genera Notorynchus, Carcharias, Carcharoides, Isurus and Cosmopolitodus and to abony fish genus Pagrus.

  4. New Odostomia species (Gastropoda, Heterobranchia, Pyramidellidae) from the Miocene Pebas Formation of Western Amazonia (Peru, Colombia)

    NARCIS (Netherlands)

    Aartsen, van J.J.; Wesselingh, F.P.

    2000-01-01

    Odostomia nuttalli spec. nov. and O. coluhensis spec. nov. are described from the Miocene Pebas Formation of Peruvian and Columbian Amazonia. A third pyramidellid snail is also diagnosed. These species are indicators for marine influence in the late Middle to early Late Miocence of Western Amazonia.

  5. The Middle Miocene climate as modelled in an atmosphere-ocean-biosphere model

    Directory of Open Access Journals (Sweden)

    M. Krapp

    2011-11-01

    Full Text Available We present simulations with a coupled atmosphere-ocean-biosphere model for the Middle Miocene 15 million years ago. The model is insofar more consistent than previous models because it captures the essential interactions between ocean and atmosphere and between atmosphere and vegetation. The Middle Miocene topography, which alters both large-scale ocean and atmospheric circulations, causes a global warming of 0.7 K compared to present day. Higher than present-day CO2 levels of 480 and 720 ppm cause a global warming of 2.8 and 4.9 K. The associated water vapour feedback enhances the greenhouse effect which leads to a polar amplification of the warming. These results suggest that higher than present-day CO2 levels are necessary to drive the warm Middle Miocene climate, also because the dynamic vegetation model simulates a denser vegetation which is in line with fossil records. However, we do not find a flatter than present-day equator-to-pole temperature gradient as has been suggested by marine and terrestrial proxies. Instead, a compensation between atmospheric and ocean heat transport counteracts the flattening of the temperature gradient. The acclaimed role of the large-scale ocean circulation in redistributing heat cannot be supported by our results. Including full ocean dynamics, therefore, does not solve the problem of the flat temperature gradient during the Middle Miocene.

  6. Simulating a Dynamic Antarctic Ice Sheet in the Early to Middle Miocene

    Science.gov (United States)

    Gasson, E.; DeConto, R.; Pollard, D.; Levy, R. H.

    2015-12-01

    There are a variety of sources of geological data that suggest major variations in the volume and extent of the Antarctic ice sheet during the early to middle Miocene. Simulating such variability using coupled climate-ice sheet models is problematic due to a strong hysteresis effect caused by height-mass balance feedback and albedo feedback. This results in limited retreat of the ice sheet once it has reached the continental size, as likely occurred prior to the Miocene. Proxy records suggest a relatively narrow range of atmospheric CO2 during the early to middle Miocene, which exacerbates this problem. We use a new climate forcing which accounts for ice sheet-climate feedbacks through an asynchronous GCM-RCM coupling, which is able to better resolve the narrow Antarctic ablation zone in warm climate simulations. When combined with recently suggested mechanisms for retreat into subglacial basins due to ice shelf hydrofracture and ice cliff failure, we are able to simulate large-scale variability of the Antarctic ice sheet in the Miocene. This variability is equivalent to a seawater oxygen isotope signal of ~0.5 ‰, or a sea level equivalent change of ~35 m, for a range of atmospheric CO2 between 280 - 500 ppm.

  7. 3-D seismic characterization of submarine landslides on a Miocene carbonate platform (Luconia Province, Malaysia)

    NARCIS (Netherlands)

    Zampetti, V.; Schlager, W.; van Konijnenburg, J.H; Everts, A.J.

    2004-01-01

    3-D seismic reflection data and a variance cube are used to determine the architecture and investigate the triggering processes of submarine landslides affecting the flanks of a Miocene carbonate platform in the Luconia Province, Malaysia. The slide masses exhibit, in time-slice displays, chaotic,

  8. Effect of ocean gateways on the global ocean circulation in the late Oligocene and early Miocene

    NARCIS (Netherlands)

    von der Heydt, A.S.|info:eu-repo/dai/nl/245567526; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467

    2006-01-01

    We investigate the effect of changes in the tectonic boundary conditions on global ocean circulation patterns. Using a fully coupled climate model in an idealized setup, we compare situations corresponding to the late Oligocene, the early Miocene, and present day. The model results show the

  9. A new baleen whale from the Late Miocene of Denmark and early mysticete hearing

    DEFF Research Database (Denmark)

    Steeman, Mette Elstrup

    2009-01-01

    here is a new, almost complete fossil baleen whale Uranocetus gramensis gen. et sp. nov. from the Upper Miocene Gram Formation in South West Denmark. It is the first stem-balaenopterid that has an initial stage of reduction in the mandibular cavity and a rostral configuration that is intermediate...

  10. Geochemical history of a Lower Miocene lake, the Cypris Formation, Sokolov Basin, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Kříbek, B.; Knésl, I.; Rojík, P.; Sýkorová, Ivana; Martínek, K.

    2017-01-01

    Roč. 58, č. 2 (2017), s. 169-190 ISSN 0921-2728 R&D Projects: GA ČR GA205/09/1162 Institutional support: RVO:67985891 Keywords : intracontinental Miocene * Czech Republic * geochemistry * organic matter * paleolake evolution Subject RIV: DD - Geochemistry OBOR OECD: Geology Impact factor: 2.017, year: 2016

  11. A new short-rostrum odontocete (Mammalia: Cetacea) from the middle Miocene of the Eastern Netherlands

    NARCIS (Netherlands)

    Bianucci, G.; Landini, W.

    2002-01-01

    An incomplete odontocete (Mammalia, Cetacea) skull from Middle Miocene Miste Bed (near Winterswijk in the eastern part of The Netherlands) is described as Vanbreenia trigonia, a new genus and species. The skull exhibits a short rostrum with only two maxillary teeth for each toothrow and with narrow

  12. Whiting–related sediment export along the Middle Miocene carbonate ramp of Great Bahama Bank.

    NARCIS (Netherlands)

    Turpin, M.; Emmanuel, L.; Reijmer, J.J.G.; Renard, M.

    2011-01-01

    Modern aragonite needles are present all along the modern leeward margin of Great Bahama Bank (ODP Leg 166), while Middle Miocene sediments contain needles only in more distal areas (Sites 1006 and 1007). In contrast to the rimmed, flat-topped platform topography during the Plio-Pleistocene, the

  13. The westernmost tarsier: A new genus and species from the Miocene of Pakistan

    NARCIS (Netherlands)

    Zijlstra, Jelle S.; Flynn, Lawrence J.; Wessels, Wilma

    2013-01-01

    As the closest living sister group of anthropoids, tarsiers (Family Tarsiidae) are an important group in primate evolution. However, their fossil record is poor: only four species have been described, two from the Eocene of China and two from the Miocene of Thailand. All are from outside the range

  14. Middle Miocene E-W tectonic horst structure of Crete through extensional detachment faults

    International Nuclear Information System (INIS)

    Papanikolaou, D; Vassilakis, E

    2008-01-01

    Two east-west trending extensional detachment faults have been recognized in Crete, one with top-to-the-north motion of the hanging wall toward the Cretan Sea and one with top-to-the-south motion of the hanging wall toward the Libyan Sea. The east-west trending zone between these two detachment faults, which forms their common footwall, comprises a tectonic horst formed during Middle Miocene slip on the detachment faults. The detachment faults disrupt the overall tectono-stratigraphic succession of Crete and are localized along pre-existing thrust faults and along particular portions of the stratigraphic sequence, including the transition between the Permo-Triassic Tyros Beds and the base of the Upper Triassic-Eocene carbonate platform of the Tripolis nappe. By recognizing several different tectono-stratigraphic formations within what is generally termed the 'phyllite-quartzite', it is possible to distinguish these extensional detachment faults from thrust faults and minor discontinuities in the sequence. The deformation history of units within Crete can be summarized as: (i) compressional deformation producing arc-parallel east-west trending south-directed thrust faults in Oligocene to Early Miocene time (ii) extensional deformation along arc-parallel, east-west trending detachment faults in Middle Miocene time, with hanging wall motion to the north and south; (iii) Late Miocene-Quaternary extensional deformation along high-angle normal and oblique normal faults that disrupt the older arc-parallel structures

  15. The influence of late Miocene exhumation on the petroleum systems of the greater Caucasus foreland basins

    International Nuclear Information System (INIS)

    Andy, A.; Colin, D.; Sally, H.; Simon, O.

    2002-01-01

    Full text: Northwards impingement of Arabia during the Cenozoic led to the inversion of the Mesozoic Greater Caucasus Basin and the associated development of areas of enhanced subsidence. However, there is great debate regarding the timing of initiation of thrusting and uplift in the Caucasus region.Traditionally, ages ranging from Middle Eocene through to Middle Miocene have been proposed.More recently. It has become clear that although deformation and flexural subsidence may have initiated during the Late Miocene to Pliocene.The potential causative mechanisms for this late uplift and exhumation did not begin until the Late Miocene to Pliocene.The potential causative mechanisms for this late uplift event have been identified.The late Miocene to Pliocene event influenced a broad region and had important implications for reservoir rock deposition and the generation,migration,trapping and preservation of hydrocarbons in the surrounding basins (e.g. Indolo-Kuban,Terek-Caspian, South Caspian, Kura-Kartli, Rion, Black Sea).One area of particular interest is the development of the Stavropol Arch through time,since foreland basins are presently restricted to the Indolo-Kuban and Terek-Caspian Sub-basins.The Stavropol Arch lies immediately north of the central, most elevated parts of the Caucasus Mountains and separates the main areas of enhanced foreland subsidence.Although in most palaeogeographic reconstructions of the area, the Stavropol Arch is shown as an uplifted massif during much of the Mesozoic and Lower Cenozoic, it seems likely from recent studies that it is a feature of Late Miocene to Pliocene exhumation.One major potential implication is that an Oligocene to Miocene (foreland) succession developed in a major basin across the whole region north of the Greater Caucasus.Much of this was subsequently eroded from the Stavropol Arch during uplift and exhumation, separating the Indolo-Kuban and Terek-Caspian foreland basins.From qualitative section balancing we

  16. Miocene denudation history of Himalaya deduced from IODP Exp. 354 Bengal Fan

    Science.gov (United States)

    Kohki, Y.; Cruz, J. W.; Osaki, A.; Manoj, M. C.; Hatano, N.; France-Lanord, C.; Spiess, V.; Klaus, A.

    2017-12-01

    The submarine Bengal Fan is the largest submarine fan on Earth and covers the whole Bay of Bengal. The sediments are fed by the Ganges and Brahmaputra rivers reflecting India-Asia plate collision. The sediments recovered from IODP Expedition 354 Bengal Fan record the uplift history of the Himalayan orogenic system. We examined the chemical composition of detrital garnets in the Miocene deposits from Site U1451, where drilling reached to basal horizon of the fan deposits, in order to reveal the detailed denudation history of Himalayan metamorphic rocks. For this purpose, the comparison of chemical composition between detrital garnet in the Bengal Fan deposits and metamorphic garnet in Himalayan metamorphic rocks was carried out. The chemical composition of the metamorphic garnet from Higher Himalayan Crystalline (HHC) in Karnali and Kaligandaki areas, western Nepal, was examined for chemical reference to detrital garnets in Bengal Fan. The metamorphic garnets in "Formation I (Le Fort, 1975)" in HHC are characterized by almandine-rich garnet with high pyrope content. Also, the garnets in "Formation II" are remarked by two types of garnets, i.e., almandine-rich and grandite-rich garnets. Meanwhile, the composition of garnets in "Formation III" is almandine-rich garnet with low pyrope content. In the Bengal Fan deposits, the characteristic garnets, which show the similarity to the metamorphic garnet in HHC, is not found from the Lower Miocene (Burdigalian) deposits. In the Middle and Upper Miocene deposits, the almandine-rich garnets characteristic in Formation I, are normally included. At the basal part of the Middle Miocene (Langhian), almandine-rich garnets with low pyrope content, suggesting the derivation from Formation III, are remarkable. The grandite-rich garnets from Formation II are sporadically found In the Upper Miocene deposits (Tortonian-Messinian). Above chemical comparison between the detrital garnets in Bengal Fan and metamorphic garnets from HHC

  17. New sedimentological and palynological data from surface Miocene strata in the central Amazonas Basin area

    Directory of Open Access Journals (Sweden)

    Emílio Alberto Amaral Soares

    Full Text Available ABSTRACT The scarcity of stratigraphic data has hindered the demarcation of the outcropping area of Miocene deposits of the Amazon Basin, represented informally by the Novo Remanso Formation. Moreover, this unit is characterized by a sparse and irregular geographic distribution due to its sedimentological features and rare fossil content. Miocene deposits cropping out in central Amazonas Basin area were described in sedimentological terms and analyzed palynologically. All analyses were undertaken in samples collected at the Uatumã River banks (Itapiranga and São Sebastião do Uatumã cities. Lithostratigraphic data shows that Novo Remanso Formation consists of sandstones, with subordinate conglomerates and pelites, characteristic of a meandering fluvial paleosystem, with fluvial channel, point bar, floodplain and crevasse splay facies. The palynoflora retrieved from five samples consists exclusively of continental-origin palynomorphs dominated by angiosperms species. Trilete spores are well represented, while gymnosperms pollen grains are minor components. The presence of Psilastephanoporites tesseroporus, Syncolporites poricostatus, Jandufouria seamrogiformis and Polypodiaceoisporites potoniei ensure these deposits fits into the Grimsdalea magnaclavata palynozone (Regali et al. 1974a, b, and the Grimsdalea magnaclavata/Crassoretitriletes vanraadshooveni palynozones of Jaramillo et al. (2011 considered Middle Miocene age. This age is confirmed by the zonation of Jaramillo et al. (2011, based on the LADs of Bombacacidites baumfalki (11.57Ma and Crototricolpites annemariae (12.91Ma; and the FAD of Psilastephanoporites tesseroporus (14.00Ma. With these new data presented herein, it is possible to assume that the Miocene strata represented by the Novo Remanso Formation covers a larger area in the basin than previously considered, and that it may be extended for about 300 km until the Manacapuru village, indicating a Miocene subsidence phase.

  18. Plate tectonic model for the oligo-miocene evolution of the western Mediterranean

    Science.gov (United States)

    Cohen, Curtis R.

    1980-10-01

    This paper outlines a plate tectonic model for the Oligo-Miocene evolution of the western Mediterranean which incorporates recent data from several tectonic domains (Corsica, Sardinia, the Kabylies, Balearic promontory, Iberia, Algero-Provençal Basin and Tunisian Atlas). Following late Mesozoic anticlockwise rotation of the Iberian peninsula (including the Balearic promontory and Sardinia), late Eocene collision occurred between the Kabylies and Balearic promontory forming a NE-trending suture with NW-tectonic polarity. As a result of continued convergence between the African and European plates, a polarity flip occurred and a southward-facing trench formed south of the Kabylie—Balearic promontory suture. During late Oligocene time an E-W-trending arc and marginal basin developed behind the southward-facing trench in the area of the present-day Gulf of Lion. Opening of this basin moved the Corsica—Sardinia—Calabria—Petit Kabylie—Menorca plate southward, relative to the African plate. Early Miocene back-arc spreading in the area between the Balearic promontory and Grand Kabylie emplaced the latter in northern Algeria and formed the South Balearic Basin. Coeval with early Miocene back-arc basin development, the N-S-extension in the Gulf of Lion marginal basin changed to a more NW-SE direction causing short-lived extension in the area of the present-day Valencia trough and a 30° anticlockwise rotation of the Corsica-Sardinia-Calabria—Petit Kabylie plate away from the European plate. Early—middle Miocene deformation along the western Italian and northeastern African continental margins resulted from this rotation. During the early late Miocene (Tortonian), spreading within a sphenochasm to the southwest of Sardinia resulted in the emplacement of Petit Kabylie in northeastern Algeria.

  19. Controls on the quality of Miocene reservoirs, southern Gulf of Mexico

    Science.gov (United States)

    Gutiérrez Paredes, Hilda Clarisa; Catuneanu, Octavian; Hernández Romano, Ulises

    2018-01-01

    An investigation was conducted to determine the main controls on the reservoir quality of the middle and upper Miocene sandstones in the southern Gulf of Mexico based on core descriptions, thin section petrography and petrophysical data; as well as to explore the possible link between the sequence stratigraphic framework, depositional facies and diagenetic alterations. The Miocene deep marine sandstones are attributed to the falling-stage, lowstand, and transgressive systems tracts. The middle Miocene falling-stage systems tract includes medium-to very fine-grained, and structureless sandstones deposited in channels and frontal splays, and muddy sandstones, deposited in lobes of debrites. The lowstand and transgressive systems tracts consist of medium-to very fine-grained massive and normally graded sandstones deposited in channel systems within frontal splay complexes. The upper Miocene falling-stage systems tract includes medium-to coarse-grained, structureless sandstones deposited in channel systems and frontal splay, as well as lobes of debrites formed by grain flows and hybrid-flow deposits. The lowstand and transgressive systems tracts include fine-grained sandstones deposited in overbank deposits. The results reveal that the depositional elements with the best reservoir quality are the frontal splays deposited during the falling-stage system tracts. The reservoir quality of the Miocene sandstones was controlled by a combination of depositional facies, sand composition and diagenetic factors (mainly compaction and calcite cementation). Sandstone texture, controlled primarily by depositional facies appears more important than sandstone composition in determining reservoir quality; and compaction was more important than cementation in porosity destruction. Compaction was stopped, when complete calcite cementation occurred.

  20. The early Miocene balaenid Morenocetus parvus from Patagonia (Argentina and the evolution of right whales

    Directory of Open Access Journals (Sweden)

    Mónica R. Buono

    2017-12-01

    Full Text Available Balaenidae (right and bowhead whales are a key group in understanding baleen whale evolution, because they are the oldest surviving lineage of crown Mysticeti, with a fossil record that dates back ∼20 million years. However, this record is mostly Pliocene and younger, with most of the Miocene history of the clade remaining practically unknown. The earliest recognized balaenid is the early Miocene Morenocetus parvus Cabrera, 1926 from Argentina. M. parvus was originally briefly described from two incomplete crania, a mandible and some cervical vertebrae collected from the lower Miocene Gaiman Formation of Patagonia. Since then it has not been revised, thus remaining a frequently cited yet enigmatic fossil cetacean with great potential for shedding light on the early history of crown Mysticeti. Here we provide a detailed morphological description of this taxon and revisit its phylogenetic position. The phylogenetic analysis recovered the middle Miocene Peripolocetus as the earliest diverging balaenid, and Morenocetus as the sister taxon of all other balaenids. The analysis of cranial and periotic morphology of Morenocetus suggest that some of the specialized morphological traits of modern balaenids were acquired by the early Miocene and have remained essentially unchanged up to the present. Throughout balaenid evolution, morphological changes in skull arching and ventral displacement of the orbits appear to be coupled and functionally linked to mitigating a reduction of the field of vision. The body length of Morenocetus and other extinct balaenids was estimated and the evolution of body size in Balaenidae was reconstructed. Optimization of body length on our phylogeny of Balaenidae suggests that the primitive condition was a relatively small body length represented by Morenocetus, and that gigantism has been acquired independently at least twice (in Balaena mysticetus and Eubalaena spp., with the earliest occurrence of this trait in the late

  1. A new age model for the early-middle Miocene in the North Alpine Foreland Basin

    Science.gov (United States)

    Reichenbacher, Bettina; Krijgsman, Wout; Pippèrr, Martina; Sant, Karin; Kirscher, Uwe

    2016-04-01

    The establishment of high-resolution age models for sedimentary successions is crucial for numerous research questions in the geosciences and related disciplines. Such models provide an absolute chronology that permits precise dating of depositional episodes and related processes such as mountain uplift or climate change. Recently, our work in the Miocene sediments of the North Alpine Foreland Basin (NAFB) has revealed a significantly younger age (16.6 Myr) for sediments that were thought to have been deposited 18 Myr ago. This implies that a fundamentally revised new age model is needed for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB (20 to 15-Myr). Our new data also indicate that previously published reconstructions of early-middle Miocene palaeogeography, sedimentation dynamics, mountain uplift and climate change in the NAFB all require a critical review and revision. Further, the time-span addressed is of special interest, since it encompasses the onset of a global warming phase. However, it appears that a fundamentally revised new age model for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB can only be achieved based on a 500 m deep drilling in the NAFB for which we currently seek collaboration partners to develop a grant application to the International Continental Deep Drilling Program (ICDP). Reference: Reichenbacher, B., W. Krijgsman, Y. Lataster, M. Pippèrr, C. G. C. Van Baak, L. Chang, D. Kälin, J. Jost, G. Doppler, D. Jung, J. Prieto, H. Abdul Aziz, M. Böhme, J. Garnish, U. Kirscher, and V. Bachtadse. 2013. A new magnetostratigraphic framework for the Lower Miocene (Burdigalian/Ottnangian, Karpatian) in the North Alpine Foreland Basin. Swiss Journal of Geosciences 106:309-334.

  2. The early Miocene balaenid Morenocetus parvus from Patagonia (Argentina) and the evolution of right whales

    Science.gov (United States)

    Cozzuol, Mario A.; Fitzgerald, Erich M.G.

    2017-01-01

    Balaenidae (right and bowhead whales) are a key group in understanding baleen whale evolution, because they are the oldest surviving lineage of crown Mysticeti, with a fossil record that dates back ∼20 million years. However, this record is mostly Pliocene and younger, with most of the Miocene history of the clade remaining practically unknown. The earliest recognized balaenid is the early Miocene Morenocetus parvus Cabrera, 1926 from Argentina. M. parvus was originally briefly described from two incomplete crania, a mandible and some cervical vertebrae collected from the lower Miocene Gaiman Formation of Patagonia. Since then it has not been revised, thus remaining a frequently cited yet enigmatic fossil cetacean with great potential for shedding light on the early history of crown Mysticeti. Here we provide a detailed morphological description of this taxon and revisit its phylogenetic position. The phylogenetic analysis recovered the middle Miocene Peripolocetus as the earliest diverging balaenid, and Morenocetus as the sister taxon of all other balaenids. The analysis of cranial and periotic morphology of Morenocetus suggest that some of the specialized morphological traits of modern balaenids were acquired by the early Miocene and have remained essentially unchanged up to the present. Throughout balaenid evolution, morphological changes in skull arching and ventral displacement of the orbits appear to be coupled and functionally linked to mitigating a reduction of the field of vision. The body length of Morenocetus and other extinct balaenids was estimated and the evolution of body size in Balaenidae was reconstructed. Optimization of body length on our phylogeny of Balaenidae suggests that the primitive condition was a relatively small body length represented by Morenocetus, and that gigantism has been acquired independently at least twice (in Balaena mysticetus and Eubalaena spp.), with the earliest occurrence of this trait in the late Miocene

  3. Slope Failure Hazards at Basalt Geomorphosites: A Comparative Analysis of the Giant's Causeway World Heritage Site, UK and Penghu Marine Geopark, Taiwan.

    Science.gov (United States)

    Gruendemann, Ciaran; Chung Lin, Jiun; Smith, Bernard

    2010-05-01

    Columnar basalt landscapes hold a fascination that transcends geographical and cultural boundaries. It is because of this that they feature so prominently on the global register of significant geomorphosites. Arguably the most iconic of these basalt landscapes is the Giant's Causeway in Northern Ireland, a status recognized by its inscription as a World Heritage Site. Recognition at this level invariably brings visitor pressure, and with it concern as to the impact they exert on site integrity. Rarely, however, is the same overt concern expressed for the risks that such sites pose to the visitors - or not at least until disaster strikes. Yet, the very features that make these sites attractive - tall, exposed, largely unconstrained columns - render many of them intrinsically unstable, prone to catastrophic collapse and potentially hazardous to visitors. In this presentation we highlight the nature of these slope instability issues through a comparative analysis of two geographically contrasting basalt geomorphosites. Investigations of slope hazard at the Giant's Causeway have shown that many are linked to the distinctive structural characteristics and weathering patterns of flood basalts. Typically, individual flows comprise a columnar ‘colonnade', topped by a blocky ‘entablature' and separated from the flows above and below it by a structurally weaker, but often less-permeable, palaeosol that formed during periods of volcanic quiescence. The collapse of columns is often facilitated by a combination of weathering along ever-widening joints and wedging outwards by debris that falls into them. This gradual distortion of the colonnade makes columns increasingly susceptible to collapse. Often this is triggered by intense rainfall (perhaps following a dry spell) that rapidly infiltrates joints and is ponded on the underlying palaeosol. The precise nature of the failure (toppling or outwards rotation of the column base) is largely dictated by the nature of the

  4. Flooding Fragility Experiments and Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Curtis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tahhan, Antonio [Idaho National Lab. (INL), Idaho Falls, ID (United States); Muchmore, Cody [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nichols, Larinda [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bhandari, Bishwo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pope, Chad [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    This report describes the work that has been performed on flooding fragility, both the experimental tests being carried out and the probabilistic fragility predictive models being produced in order to use the text results. Flooding experiments involving full-scale doors have commenced in the Portal Evaluation Tank. The goal of these experiments is to develop a full-scale component flooding experiment protocol and to acquire data that can be used to create Bayesian regression models representing the fragility of these components. This work is in support of the Risk-Informed Safety Margin Characterization (RISMC) Pathway external hazards evaluation research and development.

  5. Experimental assessment of borehole wall drilling damage in basaltic rocks

    International Nuclear Information System (INIS)

    Fuenkajorn, K.; Daemen, J.J.K.

    1986-06-01

    Ring tension tests, permeability tests, and microscopic fracture studies have been performed to investigate the borehole damage induced at low confining pressure by three drilling techniques (diamond, percussion and rotary). Specimens are drilled with three hole sizes (38, 76, and 102 mm diameter) in Pomona basalt and Grande basaltic andesite. The damaged zone is characterized in terms of fractures and fracture patterns around the hole, and in terms of tensile strength reduction of the rock around the holes. Experimental results show that the thickness of the damaged zone around the hole ranges from 0.0 to 1.7 mm. A larger drill bit induces more wall damage than does a smaller one. Different drilling techniques show different damage characteristics (intensity and distribution). Damage characteristics are governed not only by drilling parameters (bit size, weight on bit, rotational speed, diamond radius, and energy), but also by properties of the rock. The weaker rock tends to show more intense damage than does the stronger one. Cracks within grains or cleavage fractures are predominant in slightly coarser grained rock (larger than 0.5 mm grain size) while intergranular cracks are predominant in very fine grained rock (smaller than 0.01 mm grain size). The damaged zones play no significant role in the flow path around a borehole plug

  6. The Disruption of Tephra Fall Deposits by Basaltic Lava Flows

    Science.gov (United States)

    Brown, R. J.; Thordarson, T.; Self, S.; Blake, S.

    2010-12-01

    Complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents of the Roza Member in the Columbia River Basalt Province, (CRBP), USA, illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter tephra fall deposits. Thin pahoehoe lobes and sheet lobes occur intercalated with tephra deposits and provide evidence for synchronous effusive and explosive activity. Tephra that accumulated on the tops of inflating pahoehoe flows became disrupted by tumuli, which dissected the overlying sheet into a series of mounds. During inflation of subjacent tumuli tephra percolated down into the clefts and rubble at the top of the lava, and in some cases came into contact with lava hot enough to thermally alter it. Lava breakouts from the tumuli intruded up through the overlying tephra deposit and fed pahoehoe flows that spread across the surface of the aggrading tephra fall deposit. Non-welded scoria fall deposits were compacted and welded to a depth of ~50 cm underneath thick sheet lobes. These processes, deduced from the field relationships, have resulted in considerable stratigraphic complexity in proximal regions. We also demonstrate that, when the advance of lava and the fallout of tephra are synchronous, the contacts of some tephra sheets can be diachronous across their extent. The net effect is to reduce the usefulness of pyroclastic deposits in reconstructing eruption dynamics.

  7. Network topology of olivine-basalt partial melts

    Science.gov (United States)

    Skemer, Philip; Chaney, Molly M.; Emmerich, Adrienne L.; Miller, Kevin J.; Zhu, Wen-lu

    2017-07-01

    The microstructural relationship between melt and solid grains in partially molten rocks influences many physical properties, including permeability, rheology, electrical conductivity and seismic wave speeds. In this study, the connectivity of melt networks in the olivine-basalt system is explored using a systematic survey of 3-D X-ray microtomographic data. Experimentally synthesized samples with 2 and 5 vol.% melt are analysed as a series of melt tubules intersecting at nodes. Each node is characterized by a coordination number (CN), which is the number of melt tubules that intersect at that location. Statistically representative volumes are described by coordination number distributions (CND). Polyhedral grains can be packed in many configurations yielding different CNDs, however widely accepted theory predicts that systems with small dihedral angles, such as olivine-basalt, should exhibit a predominant CN of four. In this study, melt objects are identified with CN = 2-8, however more than 50 per cent are CN = 4, providing experimental verification of this theoretical prediction. A conceptual model that considers the role of heterogeneity in local grain size and melt fraction is proposed to explain the formation of nodes with CN ≠ 4. Correctly identifying the melt network topology is essential to understanding the relationship between permeability and porosity, and hence the transport properties of partial molten mantle rocks.

  8. Smectite Formation from Basaltic Glass Under Acidic Conditions on Mars

    Science.gov (United States)

    Peretyazhko, T. S.; Sutter, B.; Morris, R. V.; Agresti, D. G.; Le, L.; Ming, D. W.

    2015-01-01

    Massive deposits of phyllosilicates of the smectite group, including Mg/Fe-smectite, have been identified in Mars's ancient Noachian terrain. The observed smectite is hypothesized to form through aqueous alteration of basaltic crust under neutral to alkaline pH conditions. These pH conditions and the presence of a CO2-rich atmosphere suggested for ancient Mars were favorable for the formation of large carbonate deposits. However, the detection of large-scale carbonate deposits is limited on Mars. We hypothesized that smectite deposits may have formed under acidic conditions that prevented carbonate precipitation. In this work we investigated formation of saponite at a pH of approximately 4 from Mars-analogue synthetic Adirondack basaltic glass of composition similar to Adirondack class rocks located at Gusev crater. Hydrothermal (200º Centigrade) 14 day experiments were performed with and without 10 millimoles Fe(II) or Mg under anoxic condition [hereafter denoted as anoxic_Fe, anoxic_Mg and anoxic (no addition of Fe(II) or Mg)] and under oxic condition [hereafter denoted as oxic (no addition of Fe(II) or Mg)]. Characterization and formation conditions of the synthesized saponite provided insight into the possible geochemical conditions required for saponite formation on Mars.

  9. Characterization and recognition of intraflow structures, Grande Ronde Basalt

    International Nuclear Information System (INIS)

    Long, P.E.

    1978-09-01

    This investigation was carried out as part of a feasibility study for long-term storage of nuclear waste at depth in the Pasco Basin. Three general types of intraflow structures were found at Sentinel Gap: flows with stubby, irregular columns that lack a well-developed entablature; flows consisting of multiple tiers of largely entablature-type columns; and flows with a well-developed colonnade and entablature showing a sharp break between the two. Certain features occur locally in all three types of intraflow structures: variations in fracture morphology, primary platey fracture zones, pillow-palagonite zones, and tectonically induced zones of closely spaced fractures. Fractures in each of the three types of flows were logged both at the surface and in core from Core Hole DH-5, and petrographic textures of basalt sampled from surface exposures were examined. The textures of the basalt correlate with the intraflow structures and provide a technique for identifying flows as to their general type of intraflow structure, locating internal contacts between intraflow structures and possibly estimating fracture density within flows. Fracture logging, on the other hand, does not accurately delimit intraflow structures

  10. Noble gas and carbon isotopes in Mariana Trough basalt glasses

    International Nuclear Information System (INIS)

    Bernard, M.; Jambon, A.; Gamo, T.; Nishio, Y.; Sano, Y.

    1998-01-01

    Noble gas elemental and isotopic compositions have been measured as well as the abundance of C and its isotopic ratios in 11 glasses from submarine pillow basalts collected from the Mariana Trough. The 3 He/ 4 He ratios of 8.22 and 8.51 R atm of samples dredged from the central Mariana Trough (similar18N) agree well with that of the Mid-Ocean Ridge Basalt (MORB) glasses (8.4±0.3 R atm ), whereas a mean ratio of 8.06±0.35 R atm in samples from the northern Mariana Trough (similar20N) is slightly lower than those of MORB. One sample shows apparent excess of 20 Ne and 21 Ne relative to atmospheric Ne, suggesting incorporation of solar-type Ne in the magma source. There is a positive correlation between 3 He/ 4 He and 40 Ar/ 36 Ar ratios, which may be explained by mixing between MORB-type and atmospheric noble gases. Excess 129 Xe is observed in the sample which also shows 20 Ne and 21 Ne excesses. Observed δ 13 C values of similar20N samples vary from -3.76 per thousand to -2.80 per thousand, and appear higher than those of MORB, and the corresponding CO 2 / 3 He ratios are higher than those of MARA samples at similar18N, suggesting C contribution from the subducted slab. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Design approaches for access plugs in a basalt repository

    International Nuclear Information System (INIS)

    O'Rourke, J.; Allirot, D.; O'Connor, K.

    1982-01-01

    This paper describes research, laboratory testing, and analytical approaches taken toward the development of designs for sealing boreholes, shafts, and tunnels penetrating from ground surface to a deep, mined nuclear waste repository in basalt. A material selection process leading to identification of preferred sealing materials is discussed, and the laboratory testing program to define the geochemical and geotechnical performance of these materials is described. Analysis of the environmental conditions in the Columbia Plateau basalt flows leads to identification of tentative design criteria for plug systems. These design criteria include performance of the plug as a hydraulic barrier and as a radionuclide barrier. An important problem for effective performance of a plug system as a hydraulic barrier is shown to be a potentially disturbed zone surrounding the excavation in the stressed and jointed host rock. An idealized one-dimensional numerical model is described for analyzing the performance of the plug as a barrier to radionuclide transport. The preliminary analyses led to the conclusion that the composition and dimensions of practical candidate plugs can satisfy both hydraulic and radionuclide barrier criteria. Examples of candidate designs are shown for boreholes, shafts, and tunnels. 9 references, 6 figures, 6 tables

  12. Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland.

    Science.gov (United States)

    Baynes, Edwin R C; Attal, Mikaël; Niedermann, Samuel; Kirstein, Linda A; Dugmore, Andrew J; Naylor, Mark

    2015-02-24

    Extreme flood events have the potential to cause catastrophic landscape change in short periods of time (10(0) to 10(3) h). However, their impacts are rarely considered in studies of long-term landscape evolution (>10(3) y), because the mechanisms of erosion during such floods are poorly constrained. Here we use topographic analysis and cosmogenic (3)He surface exposure dating of fluvially sculpted surfaces to determine the impact of extreme flood events within the Jökulsárgljúfur canyon (northeast Iceland) and to constrain the mechanisms of bedrock erosion during these events. Surface exposure ages allow identification of three periods of intense canyon cutting about 9 ka ago, 5 ka ago, and 2 ka ago during which multiple large knickpoints retreated large distances (>2 km). During these events, a threshold flow depth was exceeded, leading to the toppling and transportation of basalt lava columns. Despite continuing and comparatively large-scale (500 m(3)/s) discharge of sediment-rich glacial meltwater, there is no evidence for a transition to an abrasion-dominated erosion regime since the last erosive event because the vertical knickpoints have not diffused over time. We provide a model for the evolution of the Jökulsárgljúfur canyon through the reconstruction of the river profile and canyon morphology at different stages over the last 9 ka and highlight the dominant role played by extreme flood events in the shaping of this landscape during the Holocene.

  13. Structural evaluation of multifunctional flood defenses

    NARCIS (Netherlands)

    Voorendt, M.Z.; Kothuis, Baukje; Kok, Matthijs

    2017-01-01

    Flood risk reduction aims to minimize losses in low-lying areas. One of the ways to reduce flood risks is to protect land by means of flood defenses. The Netherlands has a long tradition of flood protection and, therefore, a wide variety of technical reports written

  14. Local Flood Action Groups: Governance And Resilience

    NARCIS (Netherlands)

    Forrest, Steven; Trell, Elen-Maarja; Woltjer, Johan; Macoun, Milan; Maier, Karel

    2015-01-01

    A diverse range of citizen groups focusing on flood risk management have been identified in several European countries. The paper discusses the role of flood action (citizen) groups in the context of flood resilience and will do this by analysing the UK and its diverse range of flood groups. These

  15. Adjustable Robust Strategies for Flood Protection

    NARCIS (Netherlands)

    Postek, Krzysztof; den Hertog, Dick; Kind, J.; Pustjens, Chris

    2016-01-01

    Flood protection is of major importance to many flood-prone regions and involves substantial investment and maintenance costs. Modern flood risk management requires often to determine a cost-efficient protection strategy, i.e., one with lowest possible long run cost and satisfying flood protection

  16. Evaluation of thermobarometry for spinel lherzolite fragments in alkali basalts

    Science.gov (United States)

    Ozawa, Kazuhito; Youbi, Nasrrddine; Boumehdi, Moulay Ahmed; McKenzie, Dan; Nagahara, Hiroko

    2017-04-01

    Geothermobarometry of solid fragments in kimberlite and alkali basalts, generally called "xenoliths", provides information on thermal and chemical structure of lithospheric and asthenospheric mantle, based on which various chemical, thermal, and rheological models of lithosphere have been constructed (e.g., Griffin et al., 2003; McKenzie et al., 2005; Ave Lallemant et al., 1980). Geothermobarometry for spinel-bearing peridotite fragments, which are frequently sampled from Phanerozoic provinces in various tectonic environments (Nixon and Davies, 1987), has essential difficulties, and it is usually believed that appropriated barometers do not exist for them (O'Reilly et al., 1997; Medaris et al., 1999). Ozawa et al. (2016; EGU) proposed a method of geothermobarometry for spinel lherzolite fragments. They applied the method to mantle fragments in alkali basalts from Bou Ibalhatene maars in the Middle Atlas in Morocco (Raffone et al. 2009; El Azzouzi et al., 2010; Witting et al., 2010; El Messbahi et al., 2015). Ozawa et al. (2016) obtained 0.5GPa pressure difference (1.5-2.0GPa) for 100°C variation in temperatures (950-1050°C). However, it is imperative to verify the results on the basis of completely independent data. There are three types of independent information: (1) time scale of solid fragment extraction, which may be provided by kinetics of reactions induced by heating and/or decompression during their entrapment in the host magma and transportation to the Earth's surface (Smith, 1999), (2) depth of the host basalt formation, which may be provided by the petrological and geochemical studies of the host basalts, and (3) lithosphere-asthenosphere boundary depths, which may be estimated by geophysical observations. Among which, (3) is shown to be consistent with the result in Ozawa et al. (2016). We here present that the estimated thermal structure just before the fragment extraction is fully supported by the information of (1) and (2). Spera (1984) reviewed

  17. Smoky River coal flood risk mapping study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-06-01

    The Canada-Alberta Flood Damage Reduction Program (FDRP) is designed to reduce flood damage by identifying areas susceptible to flooding and by encouraging application of suitable land use planning, zoning, and flood preparedness and proofing. The purpose of this study is to define flood risk and floodway limits along the Smoky River near the former Smoky River Coal (SRC) plant. Alberta Energy has been responsible for the site since the mine and plant closed in 2000. The study describes flooding history, available data, features of the river and valley, calculation of flood levels, and floodway determination, and includes flood risk maps. The HEC-RAS program is used for the calculations. The flood risk area was calculated using the 1:100 year return period flood as the hydrological event. 7 refs., 11 figs., 7 tabs., 3 apps.

  18. Hydration of an active shear zone: Interactions between deformation, metasomatism and magmatism - the spinel-lherzolites from the Montferrier (southern France) Oligocene basalts

    International Nuclear Information System (INIS)

    Cabanes, N.; Briqueu, L.

    1987-01-01

    Geochemical and textural investigations have been simultaneously performed on spinel-lherzolite xenoliths from the Oligo-Miocene alkali basalts of Montferrier (southern France). All the investigated samples have undergone a deformation very particular by intense shearing under high stresses (up to 1.75 kbar), low temperatures (≤900 0 C) and strain rates of about 10 -18 to 10 -15 s -1 . Mineral chemistry reveals that the Montferrier lherzolites are fragments of an undepleted relatively shallow upper mantle level located at a depth of 50 km (15 kbar). Moreover, Na and Ti enrichment in diopside would reflect a metasomatic event, also emphasized by the common occurrence of pargasite in 50-70% of the investigated samples. Crystallization of this amphibole is attributed to a hydrous infiltration which is related in time and space to the deformation. Indeed, amphibole is preferentially concentrated in strongly deformed zones and in kink-band boundaries of orthopyroxene porphyroclasts. Moreover, the grain boundaries were used by the pervasive agent to percolate into the lherzolite: significant chemical variations (increase in MgO: 15% and decrease in Al 2 O 3 : 55%) are observed within the range of 7-5 μm adjacent to the grain boundary. Finally, Sr isotopic data ( 87 Sr/ 86 Sr) demonstrate that the amphibole, i.e. the metasomatic agent, is genetically related to the host lava of the xenoliths. Thus, the hydrous silicate liquid from which the amphibole has crystallized may be an early percolation of the ascending alkali magma. (orig.)

  19. Emplacement of inflated Pāhoehoe flows in the Naude's Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement

    Science.gov (United States)

    Jay, Anne E.; Marsh, Julian S.; Fluteau, Frédéric; Courtillot, Vincent

    2018-02-01

    Physical volcanological features are presented for a 710-m-thick section, of the Naude's Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are `medial or distal to source' are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source.

  20. Flood Resilient Systems and their Application for Flood Resilient Planning

    Science.gov (United States)

    Manojlovic, N.; Gabalda, V.; Antanaskovic, D.; Gershovich, I.; Pasche, E.

    2012-04-01

    Following the paradigm shift in flood management from traditional to more integrated approaches, and considering the uncertainties of future development due to drivers such as climate change, one of the main emerging tasks of flood managers becomes the development of (flood) resilient cities. It can be achieved by application of non-structural - flood resilience measures, summarised in the 4As: assistance, alleviation, awareness and avoidance (FIAC, 2007). As a part of this strategy, the key aspect of development of resilient cities - resilient built environment can be reached by efficient application of Flood Resilience Technology (FReT) and its meaningful combination into flood resilient systems (FRS). FRS are given as [an interconnecting network of FReT which facilitates resilience (including both restorative and adaptive capacity) to flooding, addressing physical and social systems and considering different flood typologies] (SMARTeST, http://www.floodresilience.eu/). Applying the system approach (e.g. Zevenbergen, 2008), FRS can be developed at different scales from the building to the city level. Still, a matter of research is a method to define and systematise different FRS crossing those scales. Further, the decision on which resilient system is to be applied for the given conditions and given scale is a complex task, calling for utilisation of decision support tools. This process of decision-making should follow the steps of flood risk assessment (1) and development of a flood resilience plan (2) (Manojlovic et al, 2009). The key problem in (2) is how to match the input parameters that describe physical&social system and flood typology to the appropriate flood resilient system. Additionally, an open issue is how to integrate the advances in FReT and findings on its efficiency into decision support tools. This paper presents a way to define, systematise and make decisions on FRS at different scales of an urban system developed within the 7th FP Project

  1. Derivation of Apollo 14 High-Al Basalts at Discrete Times: Rb-Sr Isotopic Constraints

    Science.gov (United States)

    Hui. Hejiu; Neal, Clive, R.; Shih, Chi-Yu; Nyquist, Laurence E.

    2012-01-01

    Pristine Apollo 14 (A-14) high-Al basalts represent the oldest volcanic deposits returned from the Moon [1,2] and are relatively enriched in Al2O3 (>11 wt%) compared to other mare basalts (7-11 wt%). Literature Rb-Sr isotopic data suggest there are at least three different eruption episodes for the A-14 high-Al basalts spanning the age range approx.4.3 Ga to approx.3.95 Ga [1,3]. Therefore, the high-Al basalts may record lunar mantle evolution between the formation of lunar crust (approx.4.4 Ga) and the main basin-filling mare volcanism (groups [5,6], and then regrouped into three with a possible fourth comprising 14072 based on the whole-rock incompatible trace element (ITE) ratios and Rb-Sr radiometric ages [7]. However, Rb-Sr ages of these basalts from different laboratories may not be consistent with each other because of the use of different 87Rb decay constants [8] and different isochron derivation methods over the last four decades. This study involved a literature search for Rb-Sr isotopic data previously reported for the high-Al basalts. With the re-calculated Rb-Sr radiometric ages, eruption episodes of A-14 high-Al basalts were determined, and their petrogenesis was investigated in light of the "new" Rb-Sr isotopic data and published trace element abundances of these basalts.

  2. Feldspar basalts in lunar soil and the nature of the lunar continents

    Science.gov (United States)

    Reid, A. M.; Ridley, W. I.; Harmon, R. S.; Warner, J.; Brett, R.; Jakes, P.; Brown, R. W.

    1974-01-01

    It is found that 25% on the Apollo-14 glasses have the same composition as the glasses in two samples taken from the Luna-16 column. The compositions are equivalent to feldspar basalt and anorthosite gabbro, and are similar to the feldspar basalts identified from Surveyor-7 analysis for lunar continents.

  3. Conceptual model for regional radionuclide transport from a basalt repository site. Final draft, technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Walton, W.C.; Voorhees, M.L.; Prickett, T.A.

    1980-05-23

    This technical memorandum was prepared to: (1) describe a typical basalt radionuclide repository site, (2) describe geologic and hydrologic processes associated with regional radionuclide transport in basalts, (3) define the parameters required to model regional radionuclide transport from a basalt repository site, and (4) develop a ''conceptual model'' of radionuclide transport from a basalt repository site. In a general hydrological sense, basalts may be described as layered sequences of aquifers and aquitards. The Columbia River Basalt, centered near the semi-arid Pasco Basin, is considered by many to be typical basalt repository host rock. Detailed description of the flow system including flow velocities with high-low hydraulic conductivity sequences are not possible with existing data. However, according to theory, waste-transport routes are ultimately towards the Columbia River and the lengths of flow paths from the repository to the biosphere may be relatively short. There are many physical, chemical, thermal, and nuclear processes with associated parameters that together determine the possible pattern of radionuclide migration in basalts and surrounding formations. Brief process descriptions and associated parameter lists are provided. Emphasis has been placed on the use of the distribution coefficient in simulating ion exchange. The use of the distribution coefficient approach is limited because it takes into account only relatively fast mass transfer processes. In general, knowledge of hydrogeochemical processes is primitive.

  4. Prokaryotic diversity, distribution, and insights into their role in biogeochemical cycling in marine basalts

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Olivia U.; Di Meo-Savoie, Carol A.; Van Nostrand, Joy D.; Zhou, Jizhong; Fisk, Martin R.; Giovannoni, Stephen J.

    2008-09-30

    We used molecular techniques to analyze basalts of varying ages that were collected from the East Pacific Rise, 9 oN, from the rift axis of the Juan de Fuca Ridge, and from neighboring seamounts. Cluster analysis of 16S rDNA Terminal Restriction Fragment Polymorphism data revealed that basalt endoliths are distinct from seawater and that communities clustered, to some degree, based on the age of the host rock. This age-based clustering suggests that alteration processes may affect community structure. Cloning and sequencing of bacterial and archaeal 16S rRNA genes revealed twelve different phyla and sub-phyla associated with basalts. These include the Gemmatimonadetes, Nitrospirae, the candidate phylum SBR1093 in the c, andin the Archaea Marine Benthic Group B, none of which have been previously reported in basalts. We delineated novel ocean crust clades in the gamma-Proteobacteria, Planctomycetes, and Actinobacteria that are composed entirely of basalt associated microflora, and may represent basalt ecotypes. Finally, microarray analysis of functional genes in basalt revealed that genes coding for previously unreported processes such as carbon fixation, methane-oxidation, methanogenesis, and nitrogen fixation are present, suggesting that basalts harbor previously unrecognized metabolic diversity. These novel processes could exert a profound influence on ocean chemistry.

  5. High-Ti type N-MORB parentage of basalts from the south Andaman ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    by Irvine and Baragar (1971) or MacDonald and. Katsura (1964) were not included here because of the considerable uncertainty that exists in such a classification scheme (see Sheth et al 2002 for more explanation). The Andaman ophiolite samples are mainly basalts (20 samples), with some basaltic andesites.

  6. Effect of basalt, silica sand and fly ash on the mechanical properties ...

    Indian Academy of Sciences (India)

    2018-05-17

    May 17, 2018 ... For this, we first manufactured binary PCs of epoxy/basalt ... Keywords. Polymer concrete; mechanical strength; mixture design; fly ash; silica sand; basalt. 1. .... To reduce the production cost of PCs, it is necessary to minimize ...

  7. Conceptual model for regional radionuclide transport from a basalt repository site. Final draft, technical memorandum

    International Nuclear Information System (INIS)

    Walton, W.C.; Voorhees, M.L.; Prickett, T.A.

    1980-01-01

    This technical memorandum was prepared to: (1) describe a typical basalt radionuclide repository site, (2) describe geologic and hydrologic processes associated with regional radionuclide transport in basalts, (3) define the parameters required to model regional radionuclide transport from a basalt repository site, and (4) develop a ''conceptual model'' of radionuclide transport from a basalt repository site. In a general hydrological sense, basalts may be described as layered sequences of aquifers and aquitards. The Columbia River Basalt, centered near the semi-arid Pasco Basin, is considered by many to be typical basalt repository host rock. Detailed description of the flow system including flow velocities with high-low hydraulic conductivity sequences are not possible with existing data. However, according to theory, waste-transport routes are ultimately towards the Columbia River and the lengths of flow paths from the repository to the biosphere may be relatively short. There are many physical, chemical, thermal, and nuclear processes with associated parameters that together determine the possible pattern of radionuclide migration in basalts and surrounding formations. Brief process descriptions and associated parameter lists are provided. Emphasis has been placed on the use of the distribution coefficient in simulating ion exchange. The use of the distribution coefficient approach is limited because it takes into account only relatively fast mass transfer processes. In general, knowledge of hydrogeochemical processes is primitive

  8. From mantle roots to surface eruptions: Cenozoic and Mesozoic continental basaltic magmatism

    Czech Academy of Sciences Publication Activity Database

    Kämpf, H.; Németh, K.; Puziewicz, J.; Mrlina, Jan; Geissler, W.H.

    2015-01-01

    Roč. 104, č. 8 (2015), s. 1909-1912 ISSN 1437-3254 Institutional support: RVO:67985530 Keywords : continental basaltic volcanism * BASALT 2013 conference * Cenozoic * Mesozoic Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.133, year: 2015

  9. Post-Columbia River Basalt Group stratigraphy and map compilation of the Columbia Plateau, Oregon

    International Nuclear Information System (INIS)

    Farooqui, S.M.; Bunker, R.C.; Thoms, R.E.; Clayton, D.C.; Bela, J.L.

    1981-01-01

    This report presents the results of reconnaissance mapping of sedimentary deposits and volcanic rocks overlying the Columbia River Basalt. The project area covers parts of the Dalles, Pendleton, Grangeville, Baker, Canyon City, and Bend. The mapping was done to provide stratigraphic data on the sedimentary deposits and volcanic rocks overlying the Columbia River Basalt Group. 160 refs., 16 figs., 1 tab

  10. Glass and mineral chemistry of northern central Indian ridge basalts: Compositional diversity and petrogenetic significance

    Digital Repository Service at National Institute of Oceanography (India)

    Ray, Dwijesh; Banerjee, R.; Iyer, S.D.; Basavalingu, B.; Mukhopadhyay, S.

    -88)), diopside (Wo sub(45-51), En sub(25-37), Fs sub14-24)), and titanomagnetite (FeO sub(t) approx. 63.5 wt% and Ti0 sub(2) approx. 22.69 wt%). The whole-rock composition of these basalts has similar Mg [mole Mg/mole(Mg+Fe sup(2+))] (VT basalt: approx. 0...

  11. Flood Hazard Areas - High Risk

    Data.gov (United States)

    Department of Homeland Security — The S_Fld_Haz_Ar table contains information about the flood hazards within the study area. A spatial file with locational information also corresponds with this data...

  12. FEMA Flood Insurance Studies Inventory

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital data set provides an inventory of Federal Emergency Management Agency (FEMA) Flood Insurance Studies (FIS) that have been conducted for communities and...

  13. Flooding characteristics of Goodloe packing

    International Nuclear Information System (INIS)

    Begovich, J.M.; Watson, J.S.

    1976-08-01

    Experimental flooding data for the countercurrent flow of air and water in a 7.62-cm-diam glass column filled with Goodloe packing were compared with a correlation reported by the packing manufacturer. Flooding rates observed in this study were as low as one-half those predicted by the correlation. Rearranging the packing by inverting the column and removing some packing segments yielded results similar to the correlation for liquid-to-gas (L/G) mass flow rate ratios greater than 10, but the experimental flooding curve fell significantly below the correlation at lower L/G ratios. When the column was repacked with new packing, the results were essentially the same as those obtained in the inverted column. Thus, it is believed that a carefully packed column is more likely to yield flooding rates similar to those obtained in the new or inverted columns rather than rates predicted by the original correlation

  14. Flood Fighting Products Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — A wave research basin at the ERDC Coastal and Hydraulics Laboratory has been modified specifically for testing of temporary, barrier-type, flood fighting products....

  15. FLOOD CHARACTERISTICS AND MANAGEMENT ADAPTATIONS ...

    African Journals Online (AJOL)

    Dr Osondu

    2011-10-26

    Oct 26, 2011 ... Ethiopian Journal of Environmental Studies and Management Vol. ... people are estimated to be at such risk by 2080 .... SCS-CN method is based on the water balance .... and psychological burden of flood hazard often fall.

  16. Introduction to flood control science

    International Nuclear Information System (INIS)

    Lee, Dong U; Ha, Jin Uk; Kim, Dong Ha; Shin, Hong Ryeol; Song, Seok Hwan; Kim, Jin Gyu; Moon, Heon Cheol

    2003-01-01

    This book covers introduction, industrialization disaster such as Bhopal and Chernobyl disaster, earthquake disaster, volcano disaster, avalanche disaster including loss allocation and prevention measures, and natural fire by showing California, Yellowstone park and similarity between fire and flood. It also introduces climate change and disaster, Earth's greenhouse effect and disaster due to current sea level rise, flood damage, drought disaster, famine and drought, prediction of drought, population problems, outlook of world population, and disaster prevention administration system of Korea.

  17. Elk River Watershed - Flood Study

    Science.gov (United States)

    Barnes, C. C.; Byrne, J. M.; MacDonald, R. J.; Lewis, D.

    2014-12-01

    Flooding has the potential to cause significant impacts to economic activities as well as to disrupt or displace populations. Changing climate regimes such as extreme precipitation events increase flood vulnerability and put additional stresses on infrastructure. Potential flooding from just under 100 (2009 NPRI Reviewed Facility Data Release, Environment Canada) toxic tailings ponds located in Canada increase risk to human safety and the environment. One such geotechnical failure spilt billions of litres of toxic tailings into the Fraser River watershed, British Columbia, when a tailings pond dam breach occurred in August 2014. Damaged and washed out roadways cut access to essential services as seen by the extensive floods that occurred in Saskatchewan and Manitoba in July 2014, and in Southern Alberta in 2013. Recovery efforts from events such as these can be lengthy, and have substantial social and economic impacts both in loss of revenue and cost of repair. The objective of this study is to investigate existing conditions in the Elk River watershed and model potential future hydrological changes that can increase flood risk hazards. By analyzing existing hydrology, meteorology, land cover, land use, economic, and settlement patterns a baseline is established for existing conditions in the Elk River watershed. Coupling the Generate Earth Systems Science (GENESYS) high-resolution spatial hydrometeorological model with flood hazard analysis methodology, high-resolution flood vulnerability base line maps are created using historical climate conditions. Further work in 2015 will examine possible impacts for a range of climate change and land use change scenarios to define changes to future flood risk and vulnerability.

  18. Magmatic evolution of the fresh basalts from the Ridge axis near Egaria Fracture Zone, Central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Mudholkar, A.V.

    was run through a computer programme of the least square and mass balance calculations for understanding the evolutionary path by differentiating minerals present in these basalts. The results indicate that the basalts under study represent a set...

  19. Correlation between compressive strength and ultrasonic pulse velocity of high strength concrete incorporating chopped basalt fibre

    Science.gov (United States)

    Shafiq, Nasir; Fadhilnuruddin, Muhd; Elshekh, Ali Elheber Ahmed; Fathi, Ahmed

    2015-07-01

    Ultrasonic pulse velocity (UPV), is considered as the most important test for non-destructive techniques that are used to evaluate the mechanical characteristics of high strength concrete (HSC). The relationship between the compressive strength of HSC containing chopped basalt fibre stands (CBSF) and UPV was investigated. The concrete specimens were prepared using a different ratio of CBSF as internal strengthening materials. The compressive strength measurements were conducted at the sample ages of 3, 7, 28, 56 and 90 days; whilst, the ultrasonic pulse velocity was measured at 28 days. The result of HSC's compressive strength with the chopped basalt fibre did not show any improvement; instead, it was decreased. The UPV of the chopped basalt fibre reinforced concrete has been found to be less than that of the control mix for each addition ratio of the basalt fibre. A relationship plot is gained between the cube compressive strength for HSC and UPV with various amounts of chopped basalt fibres.

  20. Reference waste form, basalts, and ground water systems for waste interaction studies

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.; Ledgerwood, R.K.; Long, P.E.

    1978-09-01

    This report summarizes the type of waste form, basalt, and ground water compositions to be used in theoretical and experimental models of the geochemical environment to be simulated in studying a typical basalt repository. Waste forms to be used in the experiments include, and are limited to, glass, supercalcine, and spent unreprocessed fuel. Reference basalts selected for study include the Pomona member and the Umtanum Unit, Shwana Member, of the Columbia River Basalt Group. In addition, a sample of the Basalt International Geochemical Standard (BCR-1) will be used for cross-comparison purposes. The representative water to be used is of a sodium bicarbonate composition as determined from results of analyses of deep ground waters underlying the Hanford Site. 12 figures, 13 tables.

  1. Reference waste form, basalts, and ground water systems for waste interaction studies

    International Nuclear Information System (INIS)

    Deju, R.A.; Ledgerwood, R.K.; Long, P.E.

    1978-09-01

    This report summarizes the type of waste form, basalt, and ground water compositions to be used in theoretical and experimental models of the geochemical environment to be simulated in studying a typical basalt repository. Waste forms to be used in the experiments include, and are limited to, glass, supercalcine, and spent unreprocessed fuel. Reference basalts selected for study include the Pomona member and the Umtanum Unit, Shwana Member, of the Columbia River Basalt Group. In addition, a sample of the Basalt International Geochemical Standard (BCR-1) will be used for cross-comparison purposes. The representative water to be used is of a sodium bicarbonate composition as determined from results of analyses of deep ground waters underlying the Hanford Site. 12 figures, 13 tables

  2. Influence of surface modified basalt fiber on strength of cinder lightweight aggregate concrete

    Science.gov (United States)

    Xiao, Liguang; Li, Jiheng; Liu, Qingshun

    2017-12-01

    In order to improve the bonding and bridging effect between volcanic slag lightweight aggregate concrete cement and basalt fiber, The basalt fiber was subjected to etching and roughening treatment by NaOH solution, and the surface of the basalt fiber was treated with a mixture of sodium silicate and micro-silica powder. The influence of modified basalt fiber on the strength of volcanic slag lightweight aggregate concrete was systematically studied. The experimental results show that the modified basalt fiber volcanic slag lightweight aggregate concrete has a flexural strength increased by 47%, the compressive strength is improved by 16% and the toughness is increased by 27% compared with that of the non-fiber.

  3. Using ESEM to analyze the microscopic property of basalt fiber reinforced asphalt concrete

    Directory of Open Access Journals (Sweden)

    Chunmei Gao

    2018-07-01

    Full Text Available The basalt fiber staggered distribution in the asphalt concrete matrix and the bonding situation between asphalt are analyzed by images collected using field emission environmental scanning electron microscope (ESEM test equipment. The results show that bonding of the fiber and the asphalt binder is very good and there is a strong binding force of chemical bonding connections between the two; the lipophilicity of basalt fiber is very good, the wrapped cover ability of asphalt for fiber is very strong; basalt fiber forms the local space network structure in the asphalt concrete matrix, effectively overcome the relative slip between the particles, connect the damaged parts into a whole; basalt fiber across internal micropores, and the internal defects in material can be remedied. At the same time, crack resistance mechanism of the fiber to internal micro cracks is qualitatively explained according to the magnitude of the stress intensity factor Kf. Keywords: Road engineering, Asphalt concrete, Basalt fiber, Microscopic analysis

  4. Cyber Surveillance for Flood Disasters

    Directory of Open Access Journals (Sweden)

    Shi-Wei Lo

    2015-01-01

    Full Text Available Regional heavy rainfall is usually caused by the influence of extreme weather conditions. Instant heavy rainfall often results in the flooding of rivers and the neighboring low-lying areas, which is responsible for a large number of casualties and considerable property loss. The existing precipitation forecast systems mostly focus on the analysis and forecast of large-scale areas but do not provide precise instant automatic monitoring and alert feedback for individual river areas and sections. Therefore, in this paper, we propose an easy method to automatically monitor the flood object of a specific area, based on the currently widely used remote cyber surveillance systems and image processing methods, in order to obtain instant flooding and waterlogging event feedback. The intrusion detection mode of these surveillance systems is used in this study, wherein a flood is considered a possible invasion object. Through the detection and verification of flood objects, automatic flood risk-level monitoring of specific individual river segments, as well as the automatic urban inundation detection, has become possible. The proposed method can better meet the practical needs of disaster prevention than the method of large-area forecasting. It also has several other advantages, such as flexibility in location selection, no requirement of a standard water-level ruler, and a relatively large field of view, when compared with the traditional water-level measurements using video screens. The results can offer prompt reference for appropriate disaster warning actions in small areas, making them more accurate and effective.

  5. Scales of Natural Flood Management

    Science.gov (United States)

    Nicholson, Alex; Quinn, Paul; Owen, Gareth; Hetherington, David; Piedra Lara, Miguel; O'Donnell, Greg

    2016-04-01

    The scientific field of Natural flood Management (NFM) is receiving much attention and is now widely seen as a valid solution to sustainably manage flood risk whilst offering significant multiple benefits. However, few examples exist looking at NFM on a large scale (>10km2). Well-implemented NFM has the effect of restoring more natural catchment hydrological and sedimentological processes, which in turn can have significant flood risk and WFD benefits for catchment waterbodies. These catchment scale improvements in-turn allow more 'natural' processes to be returned to rivers and streams, creating a more resilient system. Although certain NFM interventions may appear distant and disconnected from main stem waterbodies, they will undoubtedly be contributing to WFD at the catchment waterbody scale. This paper offers examples of NFM, and explains how they can be maximised through practical design across many scales (from feature up to the whole catchment). New tools to assist in the selection of measures and their location, and to appreciate firstly, the flooding benefit at the local catchment scale and then show a Flood Impact Model that can best reflect the impacts of local changes further downstream. The tools will be discussed in the context of our most recent experiences on NFM projects including river catchments in the north east of England and in Scotland. This work has encouraged a more integrated approach to flood management planning that can use both traditional and novel NFM strategies in an effective and convincing way.

  6. Flooding Effect on Earth Walls

    Directory of Open Access Journals (Sweden)

    Meysam Banimahd

    2010-12-01

    Full Text Available Earth building is a sustainable, environmentally friendly and economical method of construction that has been used worldwide for many centuries. For the past three decades, earth has seen a revival as a building material for a modern construction method due to its benefits in terms of low carbon content, low cost and energy involved during construction, as well as the fact that it is a sustainable technology of building. Climate change is influencing precipitation levels and patterns around the world, and as a consequence, flood risk is increasing rapidly. When flooding occurs, earth buildings are exposed to water by submersion, causing an increase in the degree of saturation of the earth structures and therefore a decrease of the suction between particles. This study investigated the effect of cycles of flooding (consecutive events of flooding followed by dry periods on earth walls. A series of characterization tests were carried out to obtain the physical and mechanical properties of the studied earth material. In a second stage, Flooding Simulation Tests (FST were performed to explore the earth walls’ response to repeated flooding events. The results obtained for the tested earth wall/samples with reinforced material (straw reveal hydraulic hysteresis when wall/samples are subject to cycles of wetting and drying.

  7. Gratkorn - A new late Middle Miocene vertebrate fauna from Styria (Late Sarmatian, Austria)

    Science.gov (United States)

    Gross, M.; Böhme, M.; Prieto, J.

    2009-04-01

    Integrated stratigraphic approaches provide precise correlations of global standard stages with regional Paratethys stages. Nevertheless, higher resolution stratigraphic matching of terrestrial deposits remains challenging due to the lack of a practical continental biostratigraphy. The mostly used tool for biostratigraphic correlation of non-marine deposits in the Old World is still the concept of Neogene Mammal-zones (MN-zones). However, at higher biostratigraphic resolution (reptiles (scincids, lacertids, gekkonids, anguids, varanids, colubrids, testudinids, emydids), birds (coliiformes), rodents and lagomorphs (cricetids, glirids, eomyids, sciurids, castorids), insectivores and chiropterans (erinaceids, soricids, talpids), and large mammals (suids, tragulids, moschids, cervids, ?palaeomerycids, equids, chalicotheriids, rhinos, proboscidians, carnivors). Litho- and biostratigraphy (terrestrial gastropods) as well as magnetostratigraphic data and the sequence stratigraphic and geodynamic frame indicate an age of 12-12.2 Ma (early Late Sarmatian s.str., chron 5An.1n) for the locality. Therefore, Gratkorn is one of richest and most complete fauna of the late Middle Miocene of Central Europe and will be confidentially one of the key faunas for a high-resolution continental biostratigraphy and the comprehension of the faunal succession and interchanges near the Middle/Late Miocene transition. Acknowledgements This is a preliminary overview of the Gratkorn vertebrate fauna. Several taxa are still under investigation. We are especially grateful to Gudrun Daxner-Höck, Ursula Göhlich (both Natural History Museum Vienna) and Getrud Rössner (University of Munich) for their comments to the rodents, ruminants, proboscidians and bird remains. References Böhme, M., Ilg, A., Winklhofer, M. 2008. Late Miocene "washhouse" climate in Europe.- Earth and Planetary Science Letters, 275: 393-401. Gross, M., 2008. A limnic ostracod fauna from the surroundings of the Central

  8. Potential for microbial oxidation of ferrous iron in basaltic glass.

    Science.gov (United States)

    Xiong, Mai Yia; Shelobolina, Evgenya S; Roden, Eric E

    2015-05-01

    Basaltic glass (BG) is an amorphous ferrous iron [Fe(II)]-containing material present in basaltic rocks, which are abundant on rocky planets such as Earth and Mars. Previous research has suggested that Fe(II) in BG can serve as an energy source for chemolithotrophic microbial metabolism, which has important ramifications for potential past and present microbial life on Mars. However, to date there has been no direct demonstration of microbially catalyzed oxidation of Fe(II) in BG. In this study, three different culture systems were used to investigate the potential for microbial oxidation of Fe(II) in BG, including (1) the chemolithoautotrophic Fe(II)-oxidizing, nitrate-reducing "Straub culture"; (2) the mixotrophic Fe(II)-oxidizing, nitrate-reducing organism Desulfitobacterium frappieri strain G2; and (3) indigenous microorganisms from a streambed Fe seep in Wisconsin. The BG employed consisted of clay and silt-sized particles of freshly quenched lava from the TEB flow in Kilauea, Hawaii. Soluble Fe(II) or chemically reduced NAu-2 smectite (RS) were employed as positive controls to verify Fe(II) oxidation activity in the culture systems. All three systems demonstrated oxidation of soluble Fe(II) and/or structural Fe(II) in RS, whereas no oxidation of Fe(II) in BG material was observed. The inability of the Straub culture to oxidize Fe(II) in BG was particularly surprising, as this culture can oxidize other insoluble Fe(II)-bearing minerals such as biotite, magnetite, and siderite. Although the reason for the resistance of the BG toward enzymatic oxidation remains unknown, it seems possible that the absence of distinct crystal faces or edge sites in the amorphous glass renders the material resistant to such attack. These findings have implications with regard to the idea that Fe(II)-Si-rich phases in basalt rocks could provide a basis for chemolithotrophic microbial life on Mars, specifically in neutral-pH environments where acid-promoted mineral dissolution and

  9. Short-circuiting magma differentiation from basalt straight to rhyolite?

    Science.gov (United States)

    Ruprecht, P.; Winslow, H.

    2017-12-01

    Silicic magmas are the product of varying degrees of crystal fractionation and crustal assimilation/melting. Both processes lead to differentiation that is step-wise rather than continuous for example during melt separation from a crystal mush (Dufek and Bachmann, 2010). However, differentiation is rarely efficient enough to evolve directly from a basaltic to a rhyolitic magma. At Volcán Puyehue-Cordón Caulle, Chile, the magma series is dominated by crystal fractionation where mixing trends between primitive and felsic end members in the bulk rock compositions are almost absent (e.g. P, FeO, TiO2 vs. SiO2). How effective fraction is in this magmatic system is not well-known. The 2011-12 eruption at Cordón Caulle provides new constraints that rhyolitic melts may be derived directly from a basaltic mush. Minor, but ubiquitous mafic, crystal-rich enclaves co-erupted with the predominantly rhyolitic near-aphyric magma. These enclaves are among the most primitive compositions erupted at Puyehue-Cordón Caulle and geochemically resemble closely basaltic magmas that are >10 ka old (Singer et al. 2008) and that have been identified as a parental tholeiitic mantle-derived magma (Schmidt and Jagoutz, 2017) for the Southern Andean Volcanic Zone. The vesiculated nature, the presence of a microlite-rich groundmass, and a lack of a Eu anomaly in these encalves suggest that they represent recharge magma/mush rather than sub-solidus cumulates and therefore have potentially a direct petrogenetic link to the erupted rhyolites. Our results indicate that under some conditions crystal fractionation can be very effective and the presence of rhyolitic magmas does not require an extensive polybaric plumbing system. Instead, primitive mantle-derived magmas source directly evolved magmas. In the case, of the magma system beneath Puyehue-Cordón Caulle, which had three historic rhyolitic eruptions (1921-22, 1960, 2011-12) these results raise the question whether rhyolite magma extraction

  10. Constructing risks – Internalisation of flood risks in the flood risk management plan

    NARCIS (Netherlands)

    Roos, Matthijs; Hartmann, T.; Spit, T.J.M.; Johann, Georg

    Traditional flood protection methods have focused efforts on different measures to keep water out of floodplains. However, the European Flood Directive challenges this paradigm (Hartmann and Driessen, 2013). Accordingly, flood risk management plans should incorporate measures brought about by

  11. Unravelling the Volcanological Complexities of a Flood Basalt Province: Volcanology, Paleomagnetism and Geochemistry, From the Deccan Volcanic Province

    Science.gov (United States)

    Jay, A. E.; Widdowson, M.; Self, S.; Mac Niocaill, C.

    2006-12-01

    The lavas of the Deccan Volcanic Province (DVP), India, were erupted across the Cretaceous-Tertiary boundary (KTB) and, as such, have been suggested as a candidate for causing the KTB mass extinction event. Understanding the development of such large outpourings of lava is essential to deducing their environmental impact. Detailed flow-by-flow logging was undertaken along four roads up the Mahabaleshwar Plateau, and a further three road sections to the north and south were investigated in order to study the volcanological style of this area of the DVP. Logging along the four roads which ascend the Mahabaleshwar Plateau was combined with detailed geochemical and paleomagnetic sampling and provides the first integrated study of its kind in the DVP. The logging demonstrated that almost all the lavas encountered were inflated pahoehoe sheet lobes. No `a'a flows were encountered and one rubbly pahoehoe flow may have been observed. Statistical analyses of XRF trace element data, and the occurrence of differing thicknesses and numbers of lava units between the paleomagnetic reversal horizon (Chron 29r/29n) and the top of the Ambenali Formation, suggest that individual sheet lobes are not greater than the width of the Plateau c. 20 km. This provides an explanation for the topography, up to 95 m in our study area, on the surface of the DVP at the time when the lavas were being erupted. As the sheet lobes were emplaced and inflated they left areas uncovered by lava, the topographic difference between these two areas could be many 10s of metres, and as this process occurred over the whole DVP the topographic differences could increase. As well as topography, this leads to other complexities. When later lavas in-fill these depressions it causes them to occur physically lower in the sequence than older lavas. This demonstrates that the previously held concept of large, flat-lying sheets lobes covering vast tracts of the province is not probable, as on the local scale tracing individual sheet lobes over just a few kms is not possible. However, tracing flow-fields, i.e. the total product of an eruptive event, over large areas should be possible, as these complexities become less important.

  12. High-precision zircon U-Pb geochronology of astronomically dated volcanic ash beds from the Mediterranean Miocene

    NARCIS (Netherlands)

    Wotzlaw, Jörn Frederik; Hüsing, Silja K.; Hilgen, Frederik J.; Schaltegger, Urs

    2014-01-01

    Several orbitally tuned Miocene sedimentary sequences around the Mediterranean contain abundant intercalated volcanic ash beds. These sequences provide the rare opportunity to directly compare radioisotopic dating methods with independent and accurate deposition ages derived from astrochronology. We

  13. Supra-generic radiolarian transfer function based late Miocene palaeomonsoonal changes in the northeastern tropical Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.; Fernandes, A.A.

    and PPT changes using % data of the late Miocene radiolarian sequence from the Sawai Bay Formation, Neill Island, Andamans. Estimated SST and salinity during southwest monsoon are not only conformable with the qualitative paleoceanography in terms...

  14. Do flood risk perceptions provide useful insights for flood risk management? Findings from central Vietnam

    OpenAIRE

    Bubeck, P.; Botzen, W.J.W.; Suu, L.T.T.; Aerts, J.C.J.H.

    2012-01-01

    Following the renewed attention for non-structural flood risk reduction measures implemented at the household level, there has been an increased interest in individual flood risk perceptions. The reason for this is the commonly-made assumption that flood risk perceptions drive the motivation of individuals to undertake flood risk mitigation measures, as well as the public's demand for flood protection, and therefore provide useful insights for flood risk management. This study empirically exa...

  15. Interim reclamation report: Basalt Waste Isolation Project exploration shaft site

    International Nuclear Information System (INIS)

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.

    1990-02-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. Extensive studies of the geotechnical aspects of the site were undertaken, including preparations for drilling a large diameter Exploratory Shaft. This report describes the development of the reclamation program for the Exploratory Shaft Facility, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 43 refs., 19 figs., 9 tabs

  16. Hydrothermal waste package interactions with methane-containing basalt groundwater

    International Nuclear Information System (INIS)

    McGrail, B.P.

    1984-11-01

    Hydrothermal waste package interaction tests with methane-containing synthetic basalt groundwater have shown that in the absence of gamma radiolysis, methane has little influence on the glass dissolution rate. Gamma radiolysis tests at fluxes of 5.5 x 10 5 and 4.4 x 10 4 R/hr showed that methane-saturated groundwater was more reducing than identical experiments where Ar was substituted for CH 4 . Dissolved methane, therefore, may be beneficial to the waste package in limiting the solubility of redox sensitive radionuclides such a 99 Tc. Hydrocarbon polymers known to form under the irradiation conditions of these tests were not produced. The presence of the waste package constituents apparently inhibited the formation of the polymers, however, the mechanism which prevented their formation was not determined

  17. Monitoring and sampling perched ground water in a basaltic terrain

    International Nuclear Information System (INIS)

    Hubbell, J.M.

    1990-01-01

    Perched ground water zones can provide significant information on water and contaminant movement. This paper presents information about perched ground water obtained from drilling and monitoring at a hazardous and radioactive waste disposal site at the Idaho National Engineering Laboratory. Six of forty-five wells drilled at the Radioactive Waste Management Complex have detected perched water in basalts above sedimentary interbeds. This paper describes the distribution and characteristics of perched ground water. It discusses perched water below the surficial sediments in wells at the RWMC, the characteristics of chemical constituents found in perched water, the implications for contaminant transport in the unsaturated zone of water, and the lateral extent of perched water. Recommendations are made to increase the probability of detecting and sampling low yield perched water zones. 6 refs., 6 figs., 2 tabs

  18. Continental crustal formation and recycling: Evidence from oceanic basalts

    Science.gov (United States)

    Saunders, A. D.; Tarney, J.; Norry, M. J.

    1988-01-01

    Despite the wealth of geochemical data for subduction-related magma types, and the clear importance of such magmas in the creation of continental crust, there is still no concensus about the relative magnitudes of crustal creation versus crustal destruction (i.e., recycling of crust into the mantle). The role of subducted sediment in the formation of the arc magmas is now well documented; but what proportion of sediment is taken into the deeper mantle? Integrated isotopic and trace element studies of magmas erupted far from presently active subduction zones, in particular basaltic rocks erupted in the ocean basins, are providing important information about the role of crustal recycling. By identifying potential chemical tracers, it is impossible to monitor the effects of crustal recycling, and produce models predicting the mass of material recycled into the mantle throughout long periods of geological time.

  19. Geoscience parameter data base handbook: granites and basalts

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    The Department of Energy has the responsibility for selecting and constructing Federal repositories for radioactive waste. The Nuclear Regulatory Commission must license such repositories prior to construction. The basic requirement in the geologic disposal of radioactive waste is stated as: placement in a geologic host whereby the radioactive waste is not in mechanical, thermal or chemical equilibrium with the object of preventing physical or chemical migration of radionuclides into the biosphere or hydrosphere in hazardous concentration (USGS, 1977). The object of this report is to document the known geologic parameters of large granite and basalt occurrences in the coterminous United States, for future evaluation in the selection and licensing of radioactive waste repositories. The description of the characteristics of certain potential igneous hosts has been limited to existing data pertaining to the general geologic character, geomechanics, and hydrology of identified occurrences. A description of the geochemistry is the subject of a separate report.

  20. Geoscience parameter data base handbook: granites and basalts

    International Nuclear Information System (INIS)

    1979-12-01

    The Department of Energy has the responsibility for selecting and constructing Federal repositories for radioactive waste. The Nuclear Regulatory Commission must license such repositories prior to construction. The basic requirement in the geologic disposal of radioactive waste is stated as: placement in a geologic host whereby the radioactive waste is not in mechanical, thermal or chemical equilibrium with the object of preventing physical or chemical migration of radionuclides into the biosphere or hydrosphere in hazardous concentration (USGS, 1977). The object of this report is to document the known geologic parameters of large granite and basalt occurrences in the coterminous United States, for future evaluation in the selection and licensing of radioactive waste repositories. The description of the characteristics of certain potential igneous hosts has been limited to existing data pertaining to the general geologic character, geomechanics, and hydrology of identified occurrences. A description of the geochemistry is the subject of a separate report