Sample records for cores drill
from WorldWideScience.org

Sample records 1 - 13 shown.



1

Very high-resolution seismo-acoustic imaging of seagrass meadows (Mediterranean Sea): Implications for carbon sink estimates

Lo Iacono, Claudio; Mateo, Miguel Angel; Gràcia i Mont, Eulàlia; Guasch, Lluis; Carbonell, Ramón; Serrano, Laura; Serrano, Oscar; Dañobeitia, Juan José
2008-09-01

Digital.CSIC (Spain)

2

The subsurface geology of Río Tinto: material examined during a simulated Mars drilling mission for the Mars Astrobiology Research and Technology Experiment (MARTE)

Prieto Ballesteros, Olga; Martínez-Frías, Jesús; Schutt, John; Sutter, Brad; Heldmann, Jennifer L.; Bell, Mary Sue; Battler, Melissa; Cannon, Howard; Gómez Elvira, Javier; Stoker, Carol R.
2008-10-01

Digital.CSIC (Spain)

3

Rasgos Geoquímicos de las Calizas de la Formación Arroyo Verde (Eoceno), en Punta Colorada. Provincia de Río Negro. Argentina: Reconstrucción Paleoambiental/ Geochemical features of limestones in Arroyo Verde Formation (Eocene) in Punta Colorada. Río Negro Province. Argentina: Palaeoenvironmental reconstruction

Luna, Liliana; Schillizzi, Roberto; Bonuccelli, Renzo
2008-12-01

Resumen en español El creciente desarrollo de la industria cementera ha reactivado la exploración de los yacimientos de calizas en el sur de Argentina. En la zona de Punta Colorada, a 36 km de Sierra Grande, Prov. de Río Negro, se encuentra un depósito de estas rocas pertenecientes a la Formación Arroyo Verde, del Eoceno inferior, originada por una ingresión marina ocurrida el Cretácico superior-Terciario inferior. A través de un estudio técnico se cubicaron 14.806.106 tn de reserva (mas) s medidas y 1.799.174 tn de reservas indicadas en carbonato de calidad menor al 4 % MgO. Se estudió un área de 800 Ha, dividida en 2 zonas ubicadas al norte y al sur de Punta Colorada, separadas por el Arroyo Las Palmas, en el litoral marítimo atlántico. Se determinó una potencia media de 10 m de calizas por medio de perforaciones y perfiles. El análisis de los perfiles permitió establecer 4 niveles compuestos por calizas masivas a granulares, con estratificación entrecruzada, fosilíferas. Microscópicamente se observan bivalvos, equinodermos, corales, foraminíferos y algas. La fracción clástica terrígena, tamaño arena-limo, está compuesta principalmente por cuarzo, feldespato y concreciones arcillosas verdosas. Se analizaron los tenores de CaO, MgO y se calcularon las relaciones Mg/Ca observándose variaciones verticales con aumento del MgO hacia los niveles superiores del yacimiento. Sobre la base de los porcentajes de estos óxidos se clasifica a las rocas en caliza, caliza dolomítica y dolomita calcítica. Se analizaron además Al, Fe, K, Mg, Mn, Na, P, S y Ti, observándose variaciones geoquímicas laterales y verticales que se relacionarían con cambios morfológicos, paleoambientales y de evolución de la cuenca. Se concluye que las calizas están constituidas principalmente por calcita con cantidades variables de MgO. Estas rocas se habrían formado en lagunas costeras de aguas cálidas, con alto contenido en fósforo. En otros sectores de la cuenca se habrían formado áreas pandas, con alimentación intermitente de aguas marinas, que quedaron aisladas temporalmente del ambiente marino dominante idea apoyada por el aumento en el contenido de Na y K. El contenido de Al, Fe, Mn y Ti estaría relacionado con la presencia de material terrígeno; sin embargo, el escaso aporte a la cuenca indicaría condiciones climáticas de aridez con bajo régimen pluvial. La estratificación entrecruzada en el nivel 2 se asocia a corrientes marinas. La abundancia de fósiles fragmentados revelaría la alta energía del medio. Sobre las planicies de marea las trazas de bioturbación de poco espesor, marcarían condiciones de inestabilidad, además de estadios de energía moderada a relativamente baja con tasa de sedimentación de igual calificación. En la etapa final las condiciones de depositación son marinas costeras, someras, con presencia de conchillas enteras dispersas, estratificación entrecruzada y aumento en el contenido de Fe y Mn. Mientras que en otras áreas el aumento en el contenido de azufre como yeso, señalaría una sostenida regresión del mar en dirección SO-NE. Resumen en inglés The fast growing cement industry has reactivated the exploration for calcareous materials in southern Argentina.A carbonatic deposit is found in Punta Colorada, located 36 km from the town of Sierra Grande, Río Negro Province. These rocks, deposited during a Late Cretaceous - Early Tertiary marine ingression, belong to Arroyo Verde Formation (Early Eocene). These coastal deposits have been studied since 1927 by Wichmann, Arnolds (1952), de Alba (1964), Weber (1983) and B (mas) usteros et al. (1998). Rossi de García and Levy (1982) assigned these rocks to the Eocene; Spalletti et al. (1993) located them within the Roca Formation (Rocanense ingression) and Gelós et al. (1992) correlated these rocks with Arroyo Verde Formation (Malvicini and Llambías, 1974). Arroqui Langer et al. (2006) from sedimentologic, geochemical and lithologic data in carbonatic rocks of the Precordillera Argentina established an exploration and exploitation pattern. Bonuccelli (2006) made a similar technical study in Punta Colorada, where 14,806,106 tn of measured reserves and 1,799,174 tn of indicated reserves were determined in a carbonate of less than 4% MgO grade. The study area comprise 800 Ha divided in two zones separated by Arroyo Las Palmas gully and located at the north and at the south of a basement outcrop denominated Punta Colorada, in the atlantic marine coast (Fig. 1). By means of 12 drills cores and 8 stratigraphic profiles, a thickness of 10 m was determined for the limestone. Major and minor chemical elements were determined by ICP-MA in 100 ml with two replicas in Alex Steward laboratories, Mendoza. The criterion of Tucker (1981) was used to classify the limestones by the dolomite percentage. From stratigraphic profiles four levels composed of cross-bedded massive to granular fosiliferous limestones were determined. Microscopically they are composed of a fossiliferous limestone (bioclastic packstone) with bivalves, equinoderms, corals, foraminifera and algae, being algal buildups more abundant in level three. The clastic sand to silt fraction is mainly composed of quartz, feldspar and green clay concretions. CaO and MgO contents and the relationships Mg/ Ca (Tables 1 and 2) in the stratigraphic profiles and drills cores show vertical variations with increasing MgO values toward the upper levels of the sequence. Based on the percentages of these oxides the rocks are classified as limestone, dolomitic limestone and calcitic dolomite. In drill cores Al, Fe, K, Mg, Mn, Na, P, S and Ti contents, indicate lateral and vertical variations that would be related to geomorphological and paleoenvironmental changes and to the basin evolution as well (Fig. 2, Tables 1-3). It is concluded that the limestones are mainly composed of calcite with variable quantities of MgO. These rocks would have been formed in warm lagoons with high P content. At the same time shallower areas with intermittent influx of marine waters would have been developed in other sectors. The increase in the content of Na and K in these sectors would support the idea that these evaporitic deposits were temporarily isolated from the dominant marine environment. Al, Fe, Mn and Ti concentrations would be related to the presence of terrigenous material; however, the scarce contribution to the basin would indicate climatic conditions of aridity with low pluvial regimen. Crossbedding in level 2 is associated to marine currents. The abundance of broken fossils would indicate a highly energy environment. On the tidal flat, the presence of rather thin bioturbation traces (Thalassinoides) would indicate conditions of instability during the development of this ichnofacies, as well as a rather moderate energy with low sedimentation rates. At the final stage, shallow marine, coastal, sedimentation prevail, marked by the abundance of entire shells, cross-bedding and an increment in the Fe and Mn concentration. At the same time in other sectors, the increase in the sulfur content as gypsum, would indicate a sustained SW-NE sea regression.

Scientific Electronic Library Online (Spanish)

4

Pliocene–Holocene evolution of depositional conditions in the eastern Mediterranean: Role of anoxia vs. productivity at time of sapropel deposition

Gallego-Torres, David; Martínez-Ruiz, Francisca; Paytan, Adina; Jimenez Espejo, Francisco J.; Ortega-Huertas, M.
2007-04-06

Digital.CSIC (Spain)

5

Phase relationship between sea level and abrupt climate change

Sierro, Francisco Javier; Andersen, Nils; Bassetti, Maria A.; Berné, Serge; Canals, Miquel; Curtis, Jason H.; Dennielou, Bernard; Flores, José Abel; Frigola, Jaime; Gonzalez-Mora, Beatriz; Grimalt, Joan O.; Hodell, David A.; Jouet, Gwenael; Pérez-Folgado, Marta; Schneider, Ralph
2009-08-20

Digital.CSIC (Spain)

6

Organic matter accumulation during the Holocene in the Guadalquivir marshlands (SW Spain)

Ortiz, José E.; Torres, Trinidad; López-Pamo, José E.; Soler, V.; LLamas, Juan F.; Barettino, Daniel; García, María J.
2007-07-17

Digital.CSIC (Spain)

7

MARTE: Technology development and lessons learned from a mars drilling mission simulation

Cannon, Howard N.; Stoker, Carol R.; Dunagan, Stephen E.; Davis, Kiel; Gómez-Elvira, Javier; Glass, Brian J.; Lemke, Lawrence G.; Miller, David; Bonaccorsi, Rosalba; Branson, Mark; Christa, Scott; Rodríguez-Manfredi, José Antonio; Mumm, Erik; Paulsen, Gale; Roman, Matt; Winterholler, Alois; Zavaleta, Jhony R.
2007-10-24

Digital.CSIC (Spain)

8

High-resolution seismic characterization in an urban area: Subway tunnel construction in Barcelona, Spain

Martí, David; Carbonell, Ramón; Flecha, I.; Font-Capó, Jordi; Vázquez-Suñé, Enric; Pérez-Estaún, Andrés
2008-02-01

Digital.CSIC (Spain)

9

Gas hydrate disturbance fabrics of southern Hydrate Ridge sediments (ODP Leg 204): Relationship with texture and physical properties.

Piñero, Elena; Gràcia, Eulàlia; Martínez-Ruiz, Francisca; Cruz Larrasoaña, Juan; Vizcaino, Alexis; Ercilla, Gemma
2007-07-01

Digital.CSIC (Spain)

10

Four climate cycles of recurring deep and surface water destabilizations on the Iberian margin

Martrat Sotil, Belén; Grimalt, Joan O.; Shackleton, Nicholas J.; Abreu, Lucía de; Hutterli, Manuel A.; Stocker, Thomas F.
2007-06-14

Digital.CSIC (Spain)

11

Did the Late Ordovician African ice sheet reach Europe?

Gutiérrez-Marco, J. C.; Ghienne, Jean-François; Bernárdez, Enrique; Hacar, M. P.
2010-01-01

Digital.CSIC (Spain)

12

Diagenetic formation of greigite and pyrrhotite in gas hydrate marine sedimentary systems.

Larrasoaña, Juan C.; Martínez-Ruiz, Francisca; Vega, Marta; Piñero, Elena; Gràcia, Eulàlia; Musgrave, Robert J.; Roberts, Andrew P.
2007-09-30

Digital.CSIC (Spain)

13

Abrupt wind regime changes in the North Atlantic Ocean during the past 30,000—60,000 years

López-Martínez, Constancia; Grimalt, Joan O.; Hoogakker, Babette; Gruetzner, Jens; Vautravers, Maryline J.; McCave, I. Nicholas
2006-12-15

Digital.CSIC (Spain)