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.

C and Sr Isotope Chemostratigraphy and Pb–Pb Age of Carbonate Deposits of the Vorogovka Group (Neoproterozoic), Northwest of the Yenisei Range

2019 ◽  
Vol 27 (5) ◽  
pp. 588-602
Author(s):  
B. B. Kochnev ◽  
A. B. Kuznetsov ◽  
B. G. Pokrovsky ◽  
D. R. Sitkina ◽  
Z. B. Smirnova
Keyword(s):  
Sr Isotope ◽  
Yenisei Range ◽  
Carbonate Deposits

scholarly journals Upper Proterozoic and Lower Palaeozoic strata in northern East Greenland

1989 ◽  
Vol 145 ◽  
pp. 103-108
Author(s):  
M.J Hambrey ◽  
J.S Peel ◽  
M.P Smith
Keyword(s):  
North Atlantic ◽  
The Arctic ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
East Greenland ◽  
Upper Proterozoic ◽  
Clastic Sediments ◽  
Upper Riphean ◽  
Lower Palaeozoic ◽  
The Subject

The Caledonides of East Greenland contain the best exposures of Upper Riphean to Ordovician sediments in the Arctic - North Atlantic region. At its thickest the sequence contains 13 km of Eleonore Bay Group clastic sediments and carbonates, the 0.8 km thick Tillite Group and 3 km of Cambro-Ordovician strata (Henriksen & Higgins, 1976; Henriksen, 1985). These sediments crop out in a belt stretching for nearly 300 km through the fjord region, between 71° 38' and 74° 25'N. Those in the northern part of the region, between Brogetdal in Strindberg Land and southern Payer Land, and especiaIly Albert Heim Bjerge and C. H. Ostenfeld Nunatak, were the subject of investigation during 1988 (figs 1, 2).

scholarly journals Heat flow and presence of oil and gas (the Yamal peninsula, Tomsk region)

Georesursy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 125-135
Author(s):  
Valery I. Isaev ◽  
Galina A. Lobova ◽  
Alexander N. Fomin ◽  
Valery I. Bulatov ◽  
Stanislav G. Kuzmenkov ◽  
...  
Keyword(s):  
Heat Flow ◽  
Western Siberia ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
The Arctic ◽  
Yamal Peninsula ◽  
Flow Density ◽  
Positive Anomaly ◽  
Tomsk Region ◽  
History Of

The possibilities of Geothermy as a geophysical method are studied to solve forecast and prospecting problems of Petroleum Geology of the Arctic regions and the Paleozoic of Western Siberia. Deep heat flow of Yamal fields, whose oil and gas potential is associated with the Jurassic-Cretaceous formations, and the fields of Tomsk Region, whose geological section contents deposits in the Paleozoic, is studied. The method of paleotemperature modeling was used to calculate the heat flow density from the base of a sedimentary section (by solving the inverse problem of Geothermy). The schematization and mapping of the heat flow were performed, taking into account experimental determinations of the parameter. Besides, the correlation of heat flow features with the localization of deposits was revealed. The conceptual and factual basis of research includes the tectonosedimentary history of sedimentary cover, the Mesozoic-Cenozoic climatic temperature course and the history of cryogenic processes, as well as lithologic and stratigraphic description of the section, results of well testing, thermometry and vitrinite reflectivity data of 20 deep wells of Yamal and 37 wells of Ostanino group of fields of Tomsk region. It was stated that 80 % of known Yamal deposits correlate with anomalous features of the heat flow. Bovanenkovskoe and Arkticheskoe fields are located in positive anomaly zones. 75 % of fields of Ostanino group relate to anomalous features of the heat flow. It is shown that the fields, which are characterized by existence of commercial deposits in the Paleozoic, are associated with the bright gradient zone of the heat flow. The forecast of commercial inflows in the Paleozoic for Pindzhinskoe, Mirnoe and Rybalnoe fields is given. The correlation between the intensity of naftidogenesis and the lateral inhomogeneity of the deep heat flow is characterized as a probable fundamental pattern for Western Siberia.

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>

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