Foraminifers from the Bashkirian Stage (Middle Carboniferous) Deposits of the Southern Part of the Cis-Uralian Foredeep

2019 ◽  
Vol 53 (9) ◽  
pp. 956-960
Author(s):  
E. I. Kulagina ◽  
E. N. Gorozhanina
Keyword(s):  
Middle Carboniferous ◽  
Uralian Foredeep ◽  
Bashkirian Stage

Correlation of the Type Bashkirian Stage (Middle Carboniferous, South Urals) with the Morrowan and Atokan series of the midcontinental and western United States

1999 ◽  
Vol 73 (3) ◽  
pp. 529-539 ◽  
Author(s):  
John R. Groves ◽  
Tamara I. Nemyrovska ◽  
Alexander S. Alekseev
Keyword(s):  
North American ◽  
South Urals ◽  
Correlation Technique ◽  
The North ◽  
Key Species ◽  
Composite Section ◽  
Middle Carboniferous ◽  
Shrimp Zircon Geochronology ◽  
Shrimp Zircon ◽  
Bashkirian Stage

The graphic correlation technique has been used to directly relate the stratigraphic appearances of key species in the Bashkirian Stage stratotype to those in a North American composite section. The type Bashkirian is separated from the underlying Serpukhovian Stage by an erosional unconformity and associated lacuna of undetermined, but probably minor duration. Accordingly, the base of the type Bashkirian (base of Bogdanovkian Horizon) is only slightly younger than the international mid-Carboniferous boundary. A level within the upper part of the Tashastian Horizon (Upper Bashkirian Substage) most likely correlates with the Morrowan-Atokan boundary. This level roughly coincides with a sequence boundary at the Bashkirian stratotype and with a regional unconformity in the North American midcontinent. The top of the Bashkirian Stage (top of Asatauian Horizon) is lower Atokan in North American terms. On the basis of recent 40Ar/39Ar and SHRIMP zircon geochronology studies, the age of the mid-Carboniferous boundary is estimated at 314 Ma and a horizon of early Atokan age is dated at 310.8 Ma. Accepting the present biostratigraphic correlations, these values suggest a duration for the Bashkirian Stage of slightly more than 3.2 m.y. and a duration of the Morrowan Series of slightly less than 3.2 m.y.

Calcareous foraminifers from the Bashkirian stratotype (Middle Carboniferous, south Urals) and their significance for intercontinental correlations and the evolution of the Fusulinidae

1988 ◽  
Vol 62 (3) ◽  
pp. 368-399 ◽  
Author(s):  
John R. Groves
Keyword(s):  
North American ◽  
Western Slope ◽  
South Urals ◽  
Foraminiferal Assemblage ◽  
Lower Carboniferous ◽  
The North ◽  
Middle Carboniferous ◽  
First Time ◽  
Serpukhovian Stage ◽  
Bashkirian Stage

The stratotype for the Bashkirian Stage of the Soviet Middle Carboniferous is located on the Askyn River in Gornaya Bashkiria (western slope of south Urals). Twenty-four rock samples, mostly from the lower part of the section, yielded abundant and diverse assemblages of calcareous foraminifers which are systematically described and illustrated here for the first time.The foraminiferal assemblage from the Siuransky Horizon at the base of the Bashkirian is essentially identical to that from the top of the underlying Lower Carboniferous Serpukhovian Stage. Thus, foraminifers do not provide a basis for identifying the Soviet Lower–Middle Carboniferous boundary. This notwithstanding, the presence of the foraminiferGlobivalvulina bulloides(Brady) (=G. moderataReitlinger) and the conodontIdiognathodus parvus(Dunn) in both the upper Serpukhovian and Bashkirian indicates that the base of the Bashkirian can be no older than medial to late Morrowan of the North American succession. The primitive fusulinidPseudostaffella(Pseudostaffella) appears at the bases of the lower Bashkirian Akavassky Horizon and the North American Atokan Series. The base of the Akavassky is interpreted to be somewhat older than early Atokan, however, becausePs.(Pseudostaffella) appeared in the Urals in phylogenetic continuity with its immediate ancestor, whereas in most of North America it was an immigrant.The type Bashkirian succession contains a seemingly complete phylogeny from advanced eostaffellids to primitive fusulinids.Plectostaffella jakhensis, immediate ancestor to the fusulinids, arose from a member of theEostaffella postmosquensisplexus in the late Serpukhovian.Plectostaffella jakhensis, in turn, gave rise toPs.(Semistaffella)variabilisin the early Bashkirian (late Siuransky), from which evolvedPs.(Ps.)antiquashortly thereafter (earliest Akavassky). An as yet unidentified but advanced species ofPs.(Pseudostaffella) is the most likely ancestor to late BashkirianNeostaffella ivanovi. The evolutionary series leading from theE. postmosquensisplexus to primitiveNeostaffellaapparently developed exclusively in the Eurasian–Arctic faunal realm, asPl. jakhensis, Ps.(Semistaffella)variabilis, andPs.(Ps.)antiquaare unknown in the Midcontinent–Andean region. DiversePs.(Pseudostaffella) spp. appeared in the latter area pursuant to an adaptive radiation aided by periodic interchange between faunal realms.

Carboniferous conodont biostratigraphy of the Dianzishang section, Zhenning, Guizhou, South China

2013 ◽  
Vol 151 (2) ◽  
pp. 311-327 ◽  
Author(s):  
YUPING QI ◽  
KEYI HU ◽  
QIULAI WANG ◽  
WEI LIN
Keyword(s):  
South China ◽  
North American ◽  
Primitive Form ◽  
Conodont Biostratigraphy ◽  
The World ◽  
Kasimovian Stage ◽  
Moscovian Stage ◽  
Stage Boundaries ◽  
Serpukhovian Stage ◽  
Bashkirian Stage

AbstractA preliminary summary of the lower Visean to uppermost Moscovian (Carboniferous) conodont succession and biostratigraphy of the Dianzishang section in Zhenning, Guizhou, South China is presented. Eleven conodont zones, in ascending order, can be recognized:Gnathodus praebilineatus,Gnathodus bilineatus,Lochriea ziegleri,Declinognathodus noduliferus,Neognathodus symmetricus, ‘Streptognathodus’expansus(primitive form), ‘Streptognathodus’expansus,Mesogondolella donbassica – Mesogondolella clarki,Idiognathodus podolskensis,Swadelinafauna andIdiognathodus swadeizones. The first occurrences ofLochriea ziegleriat the base of the Serpukhovian Stage,Declinognathodus noduliferus noduliferusat the base of the Bashkirian Stage and ‘Streptognathodus’expansusat the base of the Moscovian Stage are recognized. The definitions of these stage boundaries, as well as that of the base of the Kasimovian Stage are discussed. Correlations with the Naqing section in South China, Russian and North American sections, as well as other important sections in the world, are considered.

The Yenisei-Khatanga Composite Tectono-Sedimentary Element, Northern Siberia

2021 ◽  
pp. M57-2021-15
Author(s):  
E. V. Deev ◽  
G. G. Shemin ◽  
V. A. Vernikovsky ◽  
O. I. Bostrikov ◽  
P. A. Glazyrin ◽  
...  
Keyword(s):  
Siberian Craton ◽  
Middle Triassic ◽  
Foreland Basin ◽  
Early Carboniferous ◽  
Source Rocks ◽  
Total Thickness ◽  
Petroleum Potential ◽  
Early Paleocene ◽  
Middle Carboniferous ◽  
Severnaya Zemlya

AbstractThe Yenisei-Khatanga Composite Tectono-Sedimentary Element (YKh CTSE) is located between the Siberian Craton and the Taimyr-Severnaya Zemlya fold-and-thrust belt. The total thickness of the Mesoproterozoic-Cenozoic sediments of YKh CTSE reaches 20 to 25 km. They are divided into four tectono-sedimentary elements (TSE): (i) Mesoproterozoic-early Carboniferous Siberian Craton continental margin, (ii) middle Carboniferous-Middle Triassic syn-orogenic Taimyr foreland basin, (iii) late Permian-Early Triassic syn-rift, and (iv) Triassic-Early Paleocene post-rift. The last one is the most important in terms of its petroleum potential and is the most drilled part of the CTSE. Its thickness accounts for half of the total thickness of YKh CTSE. The margins of the post-rift TSE and the inner system of inversion swells and adjacent troughs and depressions were shaped by three tectonic events: (i) middle Carboniferous-Middle Triassic Taimyr orogeny, (ii) Late Jurassic-Early Cretaceous Verkhoyansk orogeny, (iii) Late Cenozoic uplift. These processes led to more intense migration of hydrocarbons, the trap formation and their infill with hydrocarbons. Triassic, Jurassic, and Lower Cretaceous source rocks are mostly gas-prone, and among 20 discovered fields in Jurassic and Cretaceous plays, 17 are gas or mixed-type fields.

Finnmark Platform Composite Tectono-Sedimentary Element, Barents Sea

2021 ◽  
pp. M57-2020-20
Author(s):  
E. Henriksen ◽  
D. Ktenas ◽  
J. K. Nielsen
Keyword(s):  
High Frequency ◽  
Oil And Gas ◽  
Barents Sea ◽  
Upper Jurassic ◽  
Source Rocks ◽  
Basement Rocks ◽  
Sea Bottom ◽  
Middle Carboniferous ◽  
Uralian Orogen ◽  
Glacial Periods

AbstractThe Finnmark Platform Composite Tectono-Sedimentary Element (CTSE), located in the southern Barents Sea, is a northward-dipping monoclinal structural unit. It covers most of the southern Norwegian Barents Sea where it borders the Norwegian Mainland. Except for the different age of basement, the CTSE extends eastwards into the Kola Monocline on the Russian part of the Barents Sea.The general water depth varies between 200-350 m, and the sea bottom is influenced by Plio-Pleistocene glaciations. A high frequency of scour marks and deposition of moraine materials exists on the platform areas. Successively older strata sub-crop below the Upper Regional Unconformity (URU, which was) formed by several glacial periods.Basement rocks of Neoproterozoic age are heavily affected by the Caledonian Orogeny, and previously by the Timanide tectonic compression in the easternmost part of the Finnmark Platform CTSE.Depth to crystalline basement varies considerably and is estimated to be from 4-5 to 10 km. Following the Caledonian orogenesis, the Finnmark Platform was affected by Lower to Middle Carboniferous rifting, sediment input from the Uralian Orogen in the east, the Upper Jurassic / Lower Cretaceous rift phase and the Late Plio-Pleistocene isostatic uplift.A total of 8 exploration wells drilled different targets on the platform. Two minor discoveries have been made proving presence of both oil and gas and potential sandstone reservoirs of good quality identified in the Visean, Induan, Anisian and Carnian intervals. In addition, thick sequences of Perm-Carboniferous carbonates and spiculitic chert are proven in the eastern Platform area. The deep reservoirs are believed to be charged from Paleozoic sources. A western extension of the Domanik source rocks well documented in the Timan-Pechora Basin may exist towards the eastern part of the Finnmark Platform. In the westernmost part, charge from juxtaposed down-faulted basins may be possible.

Modern Analogues of Sedimentation of Lower Permian Reservoirs in the Dnieper-Donets Depression

2021 ◽  
Author(s):  
Valentyn Loktyev ◽  
Sanzhar Zharkeshov ◽  
Oleg Gotsynets ◽  
Oleksandr Davydenko ◽  
Mikhailo Machuzhak ◽  
...  
Keyword(s):  
Donets Basin ◽  
Lower Permian ◽  
River Channels ◽  
Current Time ◽  
Meandering Channels ◽  
The North ◽  
Complex Picture ◽  
Middle Carboniferous ◽  
The Indian Ocean ◽  
Desert Dunes

Abstract The paper considers the problematics of identifying proper analogues for understanding carbonate and clastic reservoir distribution and prediction in the Lower Permian and Upper and Lower Carboniferous within the Dnieper-Donets basin. The focus of the exploration team was finding meandering rivers. This choice was proven good in mapping reservoirs and finding traps deeper in the Upper and Middle Carboniferous, although for Permian clastic section the approach was not helpful. The second option was desert dunes, but poor sorting of reservoirs suggests a more complex picture. Analogues such as desert environment is quite logical for describing Lower Permian as aridic climate, with red and brown shales and sands. Lower Permian reservoirs have a moon-like shape in the vertical sections that could be easily mistaken for river channels, but in such a dry climate, it is very likely water flow channels with sporadic hurricane-related activities. Core and logs shows chaotic grain sizes, but more with fine grains with almost no coarse grains. The source of sedimentary material could be mountains of Ukrainian Rock Shield from the South and Voronezh massif from the North. This conceptual model is proposing not to look for meandering channels, but more for braided channels with poorly sorted material. The current time analogue could be the Oman desert between the mountains and peninsula. From satellite images, braided channels are clearly visible in the direction towards the Indian Ocean. The channels’ internal structure is quite heterogeneous. This method suggests exploration targets with possible widths of the channels as big as hundreds of meters and their lengths under 10 and between 10-20 kilometres maximum.

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