Author
Rónald Cox
Bio: Rónald Cox is an academic researcher from Rand Afrikaans University. The author has contributed to research in topics: Diagenesis & Craton. The author has an hindex of 1, co-authored 1 publications receiving 905 citations.
Topics: Diagenesis, Craton, Silicate minerals, Provenance, Mudrock
Papers
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TL;DR: In this paper, the authors report systematic changes in mudrock composition through time on a single con- tinental cmstal block and show that the changes reflect both sediment recycling processes and changes through time in the composition of crystalline material being added to the sedimentary system and are related to tectonic evolution as the block matures from a series of accreted arc terranes to a stable craton.
1,155 citations
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TL;DR: In this paper, a series of shales and sandstones found near the source of the Sangre de Cristo, Belden, and Maroon Formations from central Colorado were examined petrographically and were analyzed for major and selected trace elements, including the REE.
762 citations
TL;DR: In this article, Petrographic, major, trace, and rare earth element compositions of sandstones from the upper Miocene Kudankulam Formation, Southern India, have been investigated to determine their provenance, tectonic setting, and weathering conditions.
Abstract: Petrographic, major, trace, and rare earth element compositions of sandstones from the upper Miocene Kudankulam Formation, Southern India, have been investigated to determine their provenance, tectonic setting, and weathering conditions. All sandstone samples are highly enriched in quartz (Q) but poor in feldspar (F) and lithic fragments (L). The major-element concentrations of these sandstones reveal the relative homogeneity of their source. Geochemically, the Kudankulam sandstones are classified as arkose, subarkose, litharenite, and sublitharenite. The CIA values (chemical index of alteration; mean value 44.5) for these sandstones and the A-CN-K diagram suggest their low-weathering nature. Similarly, their Fe2O3* + MgO (mean 2.7), Al2O3/SiO2 ( 0.09), K2O/Na2O ( 2.2) ratios and TiO2 contents ( 0.3) are consistent with a passive-margin setting. The Eu/Eu* ( 0.5), (La/Lu)cn ( 21), La/Sc ( 5.9), Th/Sc ( 1.9), La/Co ( 5.7), Th/Co ( 1.8), and Cr/Th ( 5.3) ratios support a felsic source for these sandstones. Chondrite-normalized REE patterns with LREE enrichment, flat HREE, and negative Eu anomaly also are attributed to felsic source-rock characteristics for Kudankulam sandstones. Total REE concentrations of these sandstones reflect the variations in their grain-size fractions. The source rocks are probably identified to be Proterozoic gneisses, charnockites, and granites of the Kerala Khondalite Belt, which must have been exposed at least since the late Miocene. Finally, the unusual Ni enrichment in the Kudankulam sandstones, unaccompanied by a similar enrichment in Cr, Co, and V, may be related to either the presence of pyrite in the sandstones or, more likely, the fractionation of garnet from the source rocks during transportation.
470 citations
TL;DR: In this article, the authors analyzed the Lakhanda Group of Late Mezoproterozoic age (1050-1000 Ma) from the southeastern Siberian craton in Russia for major elements and a number of trace elements, including the REE's.
386 citations
TL;DR: In this paper, major element and some trace element compositions (including the REE) of shales, carbonate-rich shales and limestones of Late Cretaceous age have been analyzed at two outcrops near Pueblo, CO.
364 citations
TL;DR: In this paper, geochemical and geochronological data for banded paragneisses and associated gneissic granitoids were collected along a NE-SW traverse in the northwestern Chinese Altai.
288 citations