The U-Pb age dating of detrital zircons from Upper Jurassic-Lower Cretaceous deposits of Stolbovoy Island (New Siberian Islands)

2014 ◽  
Vol 22 (5) ◽  
pp. 507-517 ◽  
Author(s):  
A. V. Soloviev ◽  
E. L. Miller
Keyword(s):  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Detrital Zircons ◽  
Age Dating ◽  
New Siberian Islands ◽  
Cretaceous Deposits

scholarly journals Lithology of the Upper Jurassic-Lower Cretaceous deposits of the eastern part of the Myrgovaam and Rauchua depressions, Western Chukotka

2020 ◽  
Vol 65 (4) ◽  
Author(s):  
Elena V. Vatrushkina ◽  
◽  
Marianna I. Tuchkova ◽  
Keyword(s):  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Coarse Grained ◽  
Fine Grained ◽  
Tectonic Environment ◽  
The Matrix ◽  
Siliciclastic Rocks ◽  
Facies Variation ◽  
Felsic Volcanic ◽  
Cretaceous Deposits

Upper Jurassic-Lower Cretaceous deposits were formed on the South-Western margin of the Chukotka terrane in active tectonic environment. Their stratigraphic units characterized by sedimentary structures and lithology similarities, facies variation and scarcity of reliable fauna findings. Detailed lithological studies are necessary due to the absence of a unified approach to the stratigraphic division of deposits. The paper presents petrographic, geochemical, and isotope-geochemical characteristics of Upper Jurassic-Lower Cretaceous rocks. The stages of changing the sedimentation conditions and sources, which determined the differences in sedimentological features and the composition of the studied strata, are reconstructed. The Oxford-Kimmeridgian section is composed of sandy debris flow deposits with an arcosic composition of psammitic differences. Among their sources, ancient granitoids dominated, while siliciclastic rocks, volcanites and metamorphic complexes were secondary. Volgian-valanginian interval is characterized by the accumulation of sediments in various parts of the submarine fan. In Volgian sequences fine -, medium - and coarse-grained turbidites with lenses of small-pebble conglomerates are identified. A large number of simultaneous pyroclastic material in the Volgian deposits indicates the synchronous volcanic activity. In the Volgian period, the province was dominated by volcanites, mainly of the basaltic and andesitic composition, siliciclastic rocks were present in smaller amount. The Berriasin section is composed of fine-grained turbidites with single horizons of medium-grained turbidites and gravelitic lenses, as well as slope deposits in the form of rhythmically interbedded sandstones and mudstones with slump structures. Sandstones have greywacke composition and contain an admixture of ash material in the matrix. The main sources for Berriasian deposits were siliciclastic rocks and felsic volcanic complexes. The Valanginian section is represented by fine and medium-grained turbidites with horizons of amalgamated sandstones. Sandstones are classified as arkoses by the ratio of rock-forming components. The dominant source in the Valanginian time was ancient granitoids, while siliciclastic rocks and volcanites were secondary.

Pupae of Mesozoic Jurochlus Kalugina, 1985 (Diptera: Chironomidae), with description of four new species

Zootaxa ◽  
2012 ◽  
Vol 3478 (1) ◽  
pp. 434-452 ◽  
Author(s):  
ELENA D. LUKASHEVICH ◽  
ANDREY A. PRZHIBORO
Keyword(s):  
New Species ◽  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Systematic Position ◽  
Cretaceous Deposits

The Mesozoic chironomid genus Jurochlus Kalugina, 1985, known only as pupae, is reviewed. Four new species ofJurochlus are described from the Upper Jurassic and Lower Cretaceous deposits of Mongolia, viz. J. trivittatus sp. nov.,J. limbatus sp. nov., J. lineatus sp. nov. (Shar Teg, J 3 ) and J. adustus sp. nov. (Khutel Khara, J 3 /K 1 ). Both previouslydescribed species, J. sibiricus Kalugina, 1985 and J. rigor Kalugina, 1985, are re-described in detail based on re-examination of the holotypes. The diagnosis of the genus Jurochlus is emended and its systematic position (probably Podonominae or Tanypodinae) is discussed.

scholarly journals Volcanogenic material in upper jurassic-lower cretaceous deposits of the Eastern Russian plate and its sources

2021 ◽  
Vol 21 (1) ◽  
pp. 49-57
Author(s):  
Konstantin I. Nikashin ◽  
◽  
Svetlana O. Zorina ◽  
Keyword(s):  
Rare Earth ◽  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Russian Platform ◽  
Island Arcs ◽  
Pyroclastic Material ◽  
Shale Formations ◽  
Igneous Province ◽  
Volcanic Glasses ◽  
Cretaceous Deposits

. Widespread “camouflaged” pyroclastics including smectite, illite-smectite and heulandite are detected in the upper jurassic– lower cretaceous deposits of the Ulyanovsk-Saratov basin. Moreover, volcanic glasses are found in several stratigraphic units. The quantity of pyroclastic material in the study section (17–72%) is probably related to volcanic input in the basin. Concentrations of the trace and rare earth elements point to a predominantly acid source of ash material, except the Promzino and Ulyanovsk black shale formations linked to the mixed andesite-basaltic and felsic sources. Island arcs of the Northern Tethys basin and the High-Altitude Arctic Igneous Province are regarded as probable sources of the pyroclastic influx in the epeiric basin of the Russian Platform in the Jurassic-Early Cretaceous.

The So-called Malone Jurassic Formation in Texas

1926 ◽  
Vol 63 (10) ◽  
pp. 454-469 ◽  
Author(s):  
F. L. Kitchin
Keyword(s):  
South America ◽  
Lower Cretaceous ◽  
Upper Jurassic ◽  
General Character ◽  
Late Professor ◽  
San Luis ◽  
San Luis Potosi ◽  
Jurassic Formation ◽  
San Luis Potosí ◽  
Cretaceous Deposits

The known cephalopod faunas of Upper Jurassic and earliest Cretaceous age in South America were reviewed by the late Professor V. Uhlig from the standpoint of their general character and relationships. In Mexico and in Texas certain lamellibranch species occur as part of a faunal development which Uhlig regarded as having an intimate connexion with the assemblages of the South Andean Jurassic-Cretaceous province. He remarked upon the regional unity shown by the faunas of Upper Jurassic age described by C. Burckhardt from the Mazapil district in Mexico, by Castillo and Aguilera from San Luis Potosi (Mexico), and by Cragin from the Malone district in Texas. The fossils described, from San Luis Potosi and from Cragin's so-called Malone Jurassic Formation comprise some bivalve shells, particularly Trigoniae, which resemble closely certain characteristic forms found in undoubted Lower Cretaceous deposits in South America, and also in the Africano-Indian province, of Krenkel's nomenclature.

scholarly journals Biostratigraphic partition of the Upper Jurassic and Lower Cretaceous (Oxfordian - Lower Berriasian) deposits of the Crimean Mountains for foraminiphers

2018 ◽  
Keyword(s):  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Lower Zone ◽  
Crimean Mountains ◽  
Lower Upper ◽  
Characteristic Features ◽  
Lower Berriasian ◽  
Cretaceous Deposits ◽  
Lower Kimmeridgian

Introduction. Upper Jurassic and Lower Cretaceous deposits in the Crimean Mountains are widespread and are represented by all stages ‑ Oxfordian, Kimmeridgian, Tithonian, and Berriasian. These deposits have been unevenly studied. The most studied deposits are the Oxfordian, Tithonianian and Berriasian stages. The biostratigraphic division of the Upper Jurassic and Lower Cretaceous deposits of the Mountain Crimea is based on "Stratigraphic scheme of the Upper Jurassic and Lower Cretaceous deposits of the Mountain Crimea" 2013. Purpose. Detailed biostratigraphic devision of the Upper Jurassic and Lower Cretaceous (Oxfordian ‑ Lower Berriasian) of the Mountain Crimea as results of foraminiferal analysis. Results of the study. There are five foraminiferal complexes in sections that characterize Upper Jurassic (Lower Upper Oxfordian, Lower Kimmeridgian, Upper Tithonian) and Lower Cretaceous (Lower Berriasian) age. Analysis of foraminiferal complexes allowed us to establish biostratigraphical zones in each section: oxfordiana in the Lower Oxfordian Lenticulina quenstedti-Globuligerina; in the Upper Oxfordian Lenticulina russiensis-Epistomina uhligi; in the Upper Tithonian Anchispirocyclina lusitanica-Melathrokerion spirialis; in the Lower Berriasian (lower zone) Protopeneroplis ultragranulatus-Siphoninella antiqua and layers in the Lower Kimmeridgian with Epistomina praetatariensis-Globuligerina parva. Specified foraminiferal zones were traced by us in different structural-facial zones (zone Lenticulina quenstedti-Globuligerina oxfordiana ‑ in Sudak-Feodosia; zone Lenticulina russiensis-Epistomina uhligi ‑ in Ai-Petri-Babugansk and Sudak-Feodosia; strata layers with Epistomina praetatariensis-Globuligerina parva ‑ in Sudak-Feodosia; zone Anchispirocyclina lusitanica-Melathrokerion spirialis ‑ in Sukhorychensk-Baidar, Demerdzhi-Karabijskaya and Sudak-Feodosiya; the zone of Protopeneroplis ultragranulatus-Siphoninella antiqua in Demerdzhi-Karabijskaya and Sudak-Feodosiya). Characteristic features of each foraminiferа zone include a complex of species, disappearing species, and species that continue to exist, as well as particular features of the complexes. According to lithological peculiarities and paleontological characteristics, suite and sub suite are defined. Conclusions. As a result of the study, the biostratigraphic characteristics of the sections have been specified and the paleontological characteristics of the Upper Jurassic and Lower Cretaceous deposits of the Mountain Crimea have been supplemented.

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