Results 141 to 150 of about 1,186 (177)

Habitats and probable nature of acritarchs from the Upper Riphean Chencha Formation

Paleontological Journal, 2007
Morphology and taphonomy of acritarchs from the Upper Riphean deposits of the Baikal Folded Region (eastern Siberia) are analyzed. The morphotypes of acritarchs are compared to various stages in the life cycle of modern green algae of the order Chlorococcales. The acritarchs Dictyotidium minor Stan.
A. M. Stanevich, E. N. Chatta, T. A. Kornilova, V. K. Nemerov   +3 more
exaly   +2 more sources

Reconstruction of Source-Rock Composition of the Middle and Upper Riphean Rocks of the Isherim and Bashkir Anticlinoria, Urals

Geochemistry International, 2018
It is shown that the Riphean sediments of the Bashkir and Isherim anticlinoria of the Ural mobile belt were formed in different settings. Sediments of the Bashkir Anticlinorium are autochthonous and were formed in the eastern (in present-day coordinates) Baltica from proximal siliciclastics, whereas the complexes of the Isherim Anticlinorium did not ...
A V Maslov, G A Petrov, Yu L Ronkin
exaly   +2 more sources

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, I M Gorokhov   +2 more
exaly   +2 more sources

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 ...
Harald Furnes, Johan P. Nystuen, A.O. Brunfelt, Steinar Solheim   +3 more
openalex   +2 more sources

The Upper Riphean of the Yenisei Range: Sr Chemostratigraphy and Pb–Pb Age of Limestones of the Tungusik and Shirokaya Groups

Stratigraphy and Geological Correlation, 2019
The Pb–Pb isotope age and the Sr isotope signature of the Upper Riphean sedimentary limestones from the south of the Yenisei Range on the western margin of the Siberian Craton were obtained. The Pb–Pb age of carbonate deposits of the Dadykta Formation of the Tungusik Group in the Kamenka facial zone in the east of the Yenisei Range is 1020 ± 20 Ma. The
A B Kuznetsov, B B Kochnev, G V Ovchinnikova   +2 more
exaly   +2 more sources

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 ...
N. Yu. Nikulova
openalex   +2 more sources

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 ...
Vladimir N. Sergeev
openalex   +2 more sources

Clastic Sources for the Upper Riphean Arkose Complex of the Southern Urals: Some Geochemical Constraints

Geochemistry International, 2022
A V Maslov
exaly   +2 more sources

Upper Riphean lithologic complexes of the world

International Geology Review, 1982
A B Ronov
exaly   +2 more sources

Formation Conditions of the Protoliths of Upper Riphean and Vendian Metapelites in the Bodaibo Zone, Baikal–Patom Foldbelt

Geochemistry International, 2022
V N Podkovyrov, A V Maslov
exaly   +2 more sources