Indicator minerals of kimberlitic magmatites in the sedimentary cover of the Siberian Platform.

2019 ◽  
Keyword(s):  
Siberian Platform ◽  
Sedimentary Cover ◽  
Indicator Minerals

Sr Isotope Chemostratigraphy and Pb–Pb Age of the Riphean Carbonate Deposits of the Kharaulakh Uplift (Northeastern Margin of the Siberian Platform)

2021 ◽  
Vol 62 (03) ◽  
pp. 377-387
Author(s):  
B.B. Kochnev ◽  
A.B. Kuznetsov ◽  
D.R. Sitkina ◽  
A.Yu. Kramchaninov
Keyword(s):  
Siberian Platform ◽  
Sedimentary Cover ◽  
Complex Structure ◽  
The Arctic ◽  
86Sr Ratio ◽  
Sr Isotope ◽  
Upper Riphean ◽  
Carbonate Deposits

Abstract —The least altered limestones of the Ukta and Eselekh formations in the Precambrian section of the Kharaulakh uplift have a minimum 87Sr/86Sr ratio of 0.70673–0.70715. The lowest 87Sr/86Sr ratio of the overlying Neleger and Sietachan formations is 0.70791–0.70817. Based on these data, along with the earlier obtained positive δ13С values (up to 8‰) for the Kharaulakh section, we have estimated the age of the Ukta and Eselekh formations at 800–670 Ma and the age of the Neleger and Sietachan formations at ~640–580 Ma. The Pb–Pb isochron age of the least altered limestones of the Eselekh Formation calculated from eight samples is 720 ± 30 Ma. This age permits us to define the lower part of the Kharaulakh section of the Ukta and Eselekh formations to be the late Tonian of the International Chronostratigraphic Chart or to the Upper Riphean of the General Stratigraphic Scale of Russia. The presence of reliably dated Upper Riphean sediments in the Kharaulakh uplift indicates a more complex structure of the Precambrian sedimentary cover on the Arctic margin of the Siberian Platform than assumed earlier.

Thermal history of the Siberian platform: Apatite Fission-Track data from the Permian-Triassic magmatic complexes

2021 ◽  
Author(s):  
Tatyana Bagdasaryan ◽  
Roman Veselovskiy ◽  
Viktor Zaitsev ◽  
Anton Latyshev
Keyword(s):  
Siberian Platform ◽  
Thermal History ◽  
Fission Track ◽  
Sedimentary Cover ◽  
Geothermal Gradient ◽  
State University ◽  
Apatite Fission Track ◽  
History Of ◽  
Cover Up ◽  
Moscow State University

<p>The largest continental igneous province, the Siberian Traps, was formed within the Siberian platform at the Paleozoic-Mesozoic boundary, ca. 252 million years ago. Despite the continuous and extensive investigation of the duration and rate of trap magmatism on the Siberian platform, these questions are still debated. Moreover, the post-Paleozoic thermal history of the Siberian platform is almost unknown. This study aims to reconstruct the thermal history of the Siberian platform during the last 250 Myr using the low-temperature thermochronometry. We have studied intrusive complexes from different parts of the Siberian platform, such as the Kotuy dike, the Odikhincha, Magan and Essey ultrabasic alkaline massifs, the Norilsk-1 and Kontayskaya intrusions, and the Padunsky sill. We use apatite fission-track (AFT) thermochronology to assess the time since the rocks were cooled below 110℃. Obtained AFT ages (207-173 Ma) are much younger than available U-Pb and Ar/Ar ages of the traps. This pattern might be interpreted as a long cooling of the studied rocks after their emplacement ca. 250 Ma, but this looks quite unlikely because contradicts to the geological observations. Most likely, the rocks were buried under a thick volcanic-sedimentary cover and then exhumed and cooled below 110℃ ca. 207-173 Ma. Considering the increased geothermal gradient up to 50℃/km at that times, we can estimate the thickness of the removed overlying volcanic-sedimentary cover up to 207-173 Ma as about 2-3 km.</p><p>The research was carried out with the support of RFBR (grants 20-35-90066, 18-35-20058, 18-05-00590 and 18-05-70094) and the Program of development of Lomonosov Moscow State University.</p>

scholarly journals Thermal history of the Guli pluton (north of the Siberian platform) according to apatite fission-track dating and computer modeling

2020 ◽  
Vol 11 (1) ◽  
pp. 75-87
Author(s):  
M. S. Myshenkova ◽  
V. A. Zaitsev ◽  
S. Thomson ◽  
A. V. Latyshev ◽  
V. S. Zakharov ◽  
...  
Keyword(s):  
Computer Modeling ◽  
Siberian Platform ◽  
Alternative Model ◽  
Fission Track ◽  
Sedimentary Cover ◽  
Fission Track Dating ◽  
Apatite Fission Track ◽  
First Results ◽  
History Of ◽  
Apatite Fission Track Dating

We present the first results of fission-track dating of apatite monofractions from two rock samples taken from the Southern carbonatite massif of the world’s largest alkaline ultrabasic Guli pluton (~250 Ma), located within the Maymecha-Kotuy region of the Siberain Traps. Based on the apatite fission-track data and computer modeling, we propose two alternative model of the Guli pluton's tectonothermal history. The models suggest (1) rapid post-magmatic cooling of the studied rocks in hypabyssal conditions at depth about 1.5 km, or (2) their burial under a 2-3 km thick volcano-sedimentary cover and reheating above 110°C, followed by uplift and exhumation ca. 218 Ma.

scholarly journals Geological structure and seismogeological characteristics of the continental margin of the Siberian Platform and the Laptev Sea shelf

2020 ◽  
Vol 15 (4) ◽  
Author(s):  
V.A. Kontorovich ◽  
◽  
A.Yu. Kalinin ◽  
L.M. Kalinina ◽  
M.V. Solov'ev ◽  
...  
Keyword(s):  
Continental Margin ◽  
Siberian Platform ◽  
Complex Analysis ◽  
Sedimentary Cover ◽  
Geological Structure ◽  
Water Area ◽  
Laptev Sea ◽  
Taimyr Peninsula ◽  
Upper Proterozoic ◽  
The Laptev Sea

The work is devoted to the analysis of the geological structure of the northern continental margin of the Siberian Platform and the western part of the Laptev Sea. In terms petroleum geological zoning, the study area covers the Anabar-Khatanga and Lena-Anabar petroleum bearing areas of the Lena-Tunguska petroleum province and the West Laptev Sea promising petroleum province. Seismogeological models of sedimentary stratum on the continent and in the water area are considered; the conclusion was made that the Northern Siberian and Laptev Sea basins are separated by a large basement high that extends from the Taimyr Peninsula along the coastline to the Lena River issue. A complex analysis of geological and geophysical data made it possible to conclude that the most probable model is that the western part of the Laptev Sea is a continuation of the Siberian Platform with an Archaean-Proterozoic basement and an Upper Proterozoic-Phanerozoic sedimentary cover.

scholarly journals SEISMOSTRATIGRAPHIC MODEL OF THE ALADAN-MAYA SEDIMENTARY BASIN, SOUTHEASTERN SIBERIAN PLATFORM

2020 ◽  
Vol 39 (6) ◽  
pp. 25-47
Author(s):  
E.P. Razvozzhaeva ◽  
Keyword(s):  
Siberian Platform ◽  
Oil And Gas ◽  
Sedimentary Basin ◽  
Sedimentary Cover ◽  
Parent Material ◽  
Geologic Map ◽  
Seismic Sections ◽  
Basin Boundaries

Generations of the materials of the seismic exploratory works conducted in the Aldan-Maya sedimentary basin substantiated the seismostratigraphic model and construction of the lateral and longitudinal sections allowed an understanding of the specific features of the sedimentary cover structure and specifying the basin boundaries. Based on the seismic sections and geologic map at a scale of 1: 2 500 000 a scheme of structures formed in the Riphean was developed. These constructions made it possible the purposeful plan of the oil-and-gas searching and exploratory works, estimation of thickness and area of the parent material. The investigations made can be applied for clarification of the structure of the eastern Siberian Platform.

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