Results 71 to 80 of about 126 (121)

Coastal lithofacies and biofacies associated with syndepositional dolomitization and silicification (Draken Formation, Upper Riphean, Svalbard)

Precambrian Research, 1991
The Draken Formation (120-250 m) of northeast Spitsbergen (Svalbard) forms part of a thick Upper Proterozoic carbonate platform succession. It consists predominantly of intraformational dolomitic conglomerates, with excellent textural preservation.
I J, Fairchild, A H, Knoll, K, Swett
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Geochemistry of Upper Riphean-Vendian basalts associated with the ‘sparagmites’ of southern Norway

Geological Magazine, 1983
Summary. Upper Riphean/Vendian basalt lavas within the Hedmark Group of the Osen-Røa Nappe Complex, the lowest tectonostratigraphic unit within the Scandinavian Caledonides, are typical continental tholeiites. Differences in their REE patterns may reflect source heterogeneities, while the general lack of correlation between incompatible trace element ...
H. Furnes, J. P. Nystuen, A. O. Brunfelt, S. Solheim   +3 more
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Mineralogical, Mössbauer, and Isotopic–Geochronological Study of Upper Riphean Al-glauconites, Kil'din Group, Srednii Peninsula

Lithology and Mineral Resources, 2003
The paper presents mineralogical, crystallochemical, and Rb–Sr age data on globular layer silicates of the glauconitic series from lower horizons of the Upper Riphean Kil'din Group, Srednii Peninsula. Chloritization significantly changed the globular Al-glauconite in sandstones of the Parajarvinskaya Formation.
T. A. Ivanovskaya, T. S. Zaitseva, I. M. Gorokhov, G. V. Konstantinova   +3 more
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Lithogeochemical Characteristics and Sedimentary Environments of the Uk Formation Limestones (Upper Riphean, Southern Urals)

Lithology and Mineral Resources
The lithogeochemical characteristics of the Uk Formation limestones (Uppermost Unit of the Riphean stratotype section in the Southern Urals) are considered. Data points of limestones (40 samples) accumulated in the middle and inner ramp environments have a quite contrasting distribution on diagrams with parameters (La/Sm)sh, (La/Yb)sh and (Sm/Yb)sh ...
A. V. Maslov, S. A. Dub
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New data on Sr-and C-isotopic chemostratigraphy of the Upper Riphean type section (Southern Urals)

Stratigraphy and Geological Correlation, 2006
New data on Sr-and C-isotopic systematics of carbonate rocks from the Upper Riphean stratotype (Karatau Group of the southern Urals) are obtained for several southwestern sections of the Bashkirian meganticlinorium, which have not been studied before.
A. B. Kuznetsov, M. A. Semikhatov, A. V. Maslov, I. M. Gorokhov, E. M. Prasolov, M. T. Krupenin, I. V. Kislova   +6 more
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Isotope Systematics and Age of Authigenic Minerals in Shales of the Upper Riphean Inzer Formation, South Urals

Stratigraphy and Geological Correlation, 2019
Clay subfractions (SFs) with particles size of 2–5, 0.6–2.0, 0.3–0.6, 0.2–0.3, and 0.1–0.2 μm of two shale samples (Upper Riphean Inzer Formation, South Urals) are studied using transmission electron microscopy, X-ray diffractometry (XRD), and U–Pb, Sm–Nd, Rb–Sr, and K–Ar methods.
I. M. Gorokhov, T. S. Zaitseva, A. B. Kuznetsov, G. V. Ovchinnikova, M. M. Arakelyants, V. P. Kovach, G. V. Konstantinova, T. L. Turchenko, I. M. Vasil’eva   +8 more
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PALEOBIOLOGY OF THE NEOPROTEROZOIC (UPPER RIPHEAN) SHORIKHA AND BUROVAYA SILICIFIED MICROBIOTAS, TURUKHANSK UPLIFT, SIBERIA

Journal of Paleontology, 2001
Abstract Diverse assemblages of silicified microfossils have been detected in lenses of black chert within peritidal carbonates of the Neoproterozoic (Upper Riphean) Shorikha and Burovaya formations, Turukhansk Uplift, northeastern Siberia. These microbiotas are represented by 19 species of simple filamentous and coccoidal microfossils, multicellular ...
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Formation conditions and rare-earth mineralization of Riphean carbonaceous shales of the Upper Nyatygran Subformation, Russian Far East

Russian Journal of Pacific Geology, 2017
Graphitic and graphite varieties are distinguished in the carbonaceous shales of the Riphean Upper Nyatygran Subformation in the Melgin fragment of the Turan block, eastern Bureya Massif. The protolith of the graphitic shales had a terrigenous source related to island-arc volcanism.
A. A. Cherepanov, N. V. Berdnikov, A. V. Shtareva, V. O. Krutikova   +3 more
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Upper Riphean and Lower Paleozoic Quartzite Sandstones of the Circumpolar Urals: Geochemical Characteristics, Source Areas, and Conditions of Formation

Геохимия, 2023
The results of study and comparison of geochemical characteristics of quartzite sandstones of the Upper Riphean Khobeyu and Lower Paleozoic Obeiz formations of the Circumpolar Urals are presented. It has been established that the composition of quartzite sandstone of both formations was formed mainly from recycled material of ancient metaterrigenous ...
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The Sr isotope chemostratigraphy as a tool for solving stratigraphic problems of the Upper Proterozoic (Riphean and Vendian)

Stratigraphy and Geological Correlation, 2014
Published and original data on the Sr isotopic characterization of carbonates from the Riphean and Vendian key sections of the Southern Urals, Siberia, Asia, Africa, Australia, and North America are considered in compliance with the suggested principles of reconstructing the Sr isotopic composition of the Proterozoic seawater.
A. B. Kuznetsov, M. A. Semikhatov, I. M. Gorokhov   +2 more
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