Mineralogical and geochemical characteristics (major, minor, trace elements and REE) of detrital and authigenic clay minerals in a Cenozoic sequence from Ross Sea, Antarctica

Clay Minerals ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 405-421 ◽  
Author(s):  
M. Setti ◽  
L. Marinoni ◽  
A. López-Galindo
Keyword(s):  
Trace Elements ◽  
Clay Minerals ◽  
Ross Sea ◽  
Clay Fraction ◽  
Geochemical Characteristics ◽  
Victoria Land ◽  
Victoria Land Basin ◽  
Degree Of Crystallization ◽  
Mixed Layers

AbstractThe mineralogy and geochemistry of the clay fraction of Victoria Land Basin (Ross Sea, Antarctica) sediments was investigated, to determine the origin of clay minerals and the features of authigenic smectite. The investigated core (CRP-3) is ~800 m long, mostly of Oligocene age. The clay fraction of the upper sequence consists of mica, chlorite and detrital smectite, while that of the central and lower part is largely made up of authigenic smectite. Authigenic smectites are ditrioctahedral, with a composition close to saponite, while detrital smectites such as Al-Fe beidellites are dioctahedral. Authigenic smectites have no illite mixed layers, show a higher degree of crystallization, higher MgO, Fe2O3, V, Cr, Co, Ni and Sc contents and lower SiO2, Al2O3, K2O, TiO2, Ba, Rb and Zr contents with respect to detrital clay minerals, and a clear depletion of LREE with respect to HREE. Authigenic smectite formed from the alteration of volcanic materials and clay minerals.

Clay mineral assemblages as indicators of hydrothermalism in the basal part of the CRP-3 core (Victoria Land Basin, Antarctica)

Clay Minerals ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 389-404 ◽  
Author(s):  
M. Setti ◽  
L. Marinoni ◽  
A. Lopez-Galindo
Keyword(s):  
Electron Microscopy ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Particle Morphology ◽  
Victoria Land ◽  
Mineral Assemblages ◽  
Variable Chemical ◽  
Victoria Land Basin ◽  
Glaciogenic Sediments ◽  
Glaciomarine Sediments

AbstractThe CRP-3 drilling project collected sediments from 3 to 939 mbsf (metres below sea floor) in the Victoria Land Basin in Antarctica. The upper sequence (down to ~790 m bsf) is of Cenozoic age and made up of detrital glaciogenic sediments; the characteristics of clay minerals in this part have been reported elsewhere. Here, the compositional features of clay minerals in the lower sequence such as conglomerates, Devonian sandstones and dolerites are described and genetic processes clarified. Clay minerals in the deepest part of the sequence derive from the alteration of different lithologies that mostly make up the sedimentary basin.Two clay mineral assemblages were characterized through analysis by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). From 790 to 823 mbsf, samples consist of authigenic smectite of variable chemical composition forming imbricated texture of plates or flakes. The smectites probably result from hydrothermal/diagenetic transformation of earlier minerals. The primary smectite cement underwent reorganization during shearing and cataclasis. The lowest part of the sequence (below 823 mbsf) is characterized by an assemblage of kaolinite, mixed-layer illite-smectite, Fe oxyhydroxide, sporadic smectite and poorly crystallized illite. It reflects a stronger alteration process than that recorded in the upper units of core CRP-3, related to hydrothermalism connected with the intrusion of an igneous body. Both assemblages show clear differences in particle morphology, texture and smectite composition to the clay assemblages found in the Cenozoic glaciomarine sediments in the upper sequence. The different phases of alteration appear related to the processes of rifting, exhumation and faulting that characterized this region since the Mesozoic.

scholarly journals Mineralogical Study of Levels with Magnesian Clay Minerals in the Santos Basin, Aptian Pre-Salt Brazil

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 970
Author(s):  
Maurício Dias da Silva ◽  
Márcia Elisa Boscato Gomes ◽  
André Sampaio Mexias ◽  
Manuel Pozo ◽  
Susan Martins Drago ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Clay Fraction ◽  
Total Sample ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineralogical Study ◽  
Original Rock ◽  
Mixed Layers

The object of this study is magnesian clay minerals present in carbonate rocks of the post-rift phase of the pre-salt in the Santos Basin. These rocks developed in an Aptian-age alkaline lacustrine environment. This study summarizes the formation of clay minerals associated with different lithotypes in a range of 19 m and a depth of more than 5100 m. They were characterized from petrographic analysis by optical microscopy, X-ray diffraction (total sample and clay fraction), and modeling by Newmod®; and examined and analyzed by scanning electron microscopy. An approach based on identifying lithotypes and characterization of microsites allowed us to understand the occurrence of different clay minerals. Kerolite was the most abundant mineral in the sampled range. It occurs in lamellar aggregates under greater preservation of the original rock lamination and in association with spherulites and shrubs. The Stv/Ker mixed layers occurs in the same association, and formed finer unlaminated aggregates associated with the more intense dolomitization and silicification processes. Saponite occurs associated with detrital minerals forming clayey levels intercalated with microcrystalline carbonates. Fluids with a high Mg/Si and pH < 9 favor the precipitation of kerolite. The increase in pH during diagenesis may be responsible for the formation of Stv/Ker mixed layers.

Geology of the Margin of the Victoria Land Basin off Cape Roberts, Southwest Ross Sea

2013 ◽  
pp. 183-207 ◽  
Author(s):  
P. J. Barrett ◽  
S. A. Henrys ◽  
L. R. Bartek ◽  
G. Brancolini ◽  
M. Busetti ◽  
...  
Keyword(s):  
Ross Sea ◽  
Victoria Land ◽  
Victoria Land Basin

Magnetostratigraphic chronology of a late Eocene to early Miocene glacimarine succession from the Victoria Land Basin, Ross Sea, Antarctica

2005 ◽  
Vol 45 (1-3) ◽  
pp. 207-236 ◽  
Author(s):  
Fabio Florindo ◽  
Gary S. Wilson ◽  
Andrew P. Roberts ◽  
Leonardo Sagnotti ◽  
Kenneth L. Verosub
Keyword(s):  
Ross Sea ◽  
Late Eocene ◽  
Early Miocene ◽  
Victoria Land ◽  
Victoria Land Basin

scholarly journals Contribution of mineralogical sedimentological and geochemical characteristics of deltaic deposits in the 137Cs sediment concetration

2001 ◽  
Vol 34 (3) ◽  
pp. 1107
Author(s):  
Ι. ΜΑΡΓΑΡΙΤΗΣ
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Clay Minerals ◽  
Organic Material ◽  
Clay Fraction ◽  
Field Studies ◽  
137Cs Activity ◽  
Geochemical Characteristics ◽  
Strongly Correlated ◽  
Mn Content

This parer provides a review of the factors governing 137Cs sorption in sediments. We have specially focused in the correlation between sorption and the sedimentological mineralogical and geochemical characteristics of the sediments. Literature conclusions in experimental as well as field studies on 137Cs sorption is that 137Cs is strongly correlated with the < 20μηι fraction of the sediment as well as illite content. Other clay minerals such as smectite, kaolinite and chlorite sorb 137Cs in a lesser degree. Furthermore organic material and Fe-Mn hydroxides, act like sorptive surfaces. Our data on 137Cs activity variation based on field studies from deltaic deposits (Arachthos delta, Amvrakikos gulf, Greece)is also discussed. The results of this studies confirm the above mentioned, since 137Cs activity is strongly correlated with the clay fraction and the illite content,while a lesser correlation is indicated for total organic carbon Fe and Mn content of the sediments.

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