The Burrows of Decapod Crustaceans from Paleogene Deposits of the Middle Volga Region: Paleogeographic Implications     

B. T. Yanin  V. N. Benyamovsky 《Moscow University Geology Bulletin》2018,73(2):141-149

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The Structure and Formation Conditions of the Bedenekir Formation Deposits (Thithonian Stage) of Mountainous Crimea     

R.?R.?GabdullinEmail author  N.?V.?Badulina  E.?A.?Bakai  E.?A.?Shcherbinina  E.?V.?Karpova  M.?A.?Varzanova  A.?V.?Sergienko  T.?A.?Konovalova 《Moscow University Geology Bulletin》2018,73(1):43-51

The composition and origin of the Bedenekir Formation deposits of Mountainous Crimea are detailed on the basis of our work results and analysis of both published and unpublished data.  相似文献   

The Structure and Formation Conditions of the Callovian–Oxfordian Deposits of Sudak Bay (Crimea)     

R. R. Gabdullin  N. V. Badulina  E. A. Bakai  E. V. Rubtsova  A. Yu. Yurchenko  E. V. Karpova  A. V. Ivanov  M. A. Varzanova  A. V. Sergienko  T. A. Konovalova  M. V. Parakhina 《Moscow University Geology Bulletin》2018,73(4):346-360

The composition and origin of the Callovian–Oxfordian deposits of the Sudak Bay were characterized on the basis of the generalization and analysis of our own results, as well as published and unpublished data. The botanical future was first implemented for the geological mapping of the Oxfordian deposits.  相似文献   

Calorimetric determination of the standard enthalpy of formation of stannite,Cu<Subscript>2</Subscript>FeSnS<Subscript>4</Subscript>     

T. A. Stolyarova  A. V. Baranov  E. G. Osadchii 《Geochemistry International》2018,56(1):75-77

The standard enthalpy of formation of stannite (Cu₂FeSnS₄) was calculated from the calorimetric measurements of the reactions of its formation from simple synthetic sulfides: Cu₂S + FeS₂ + SnS → Cu₂FeSnS₄ and ₂CuS + FeS + SnS → Cu₂FeSnS₄. Using published data for the binary sulfides, the standard enthalpy of formation of stannite from the elements was determined as ΔfH°_298.15(Cu₂FeSnS₄) =–(417.28 ± 2.28) kJ mol^–1.  相似文献   

Phosphides in Volcanic Seamount Basalts in the Sea of Japan     

V. T. S”edin  O. N. Kolesnik  E. I. Yaroshchuk 《Lithology and Mineral Resources》2018,53(4):324-328

Electron microprobe data on phosphide grains detected for the first time in basalts from volcanic edifices in the Sea of Japan are presented. The find of phosphides can testify to the endogenic source of phosphorus and, consequently, volcanogenic hydrothermal origin of phosphorites in the Sea of Japan.  相似文献   

Depositional setting,provenance, and tectonic-volcanic setting of Eocene–Recent deep-sea sediments of the oceanic Izu–Bonin forearc,northwest Pacific (IODP Expedition 352)     

Alastair H. F. Robertson  Steffen Kutterolf  Aaron Avery  Alan T. Baxter  Katerina Petronotis  Gary D. Acton 《International Geology Review》2018,60(15):1816-1854

New biostratigraphical, geochemical, and magnetic evidence is synthesized with IODP Expedition 352 shipboard results to understand the sedimentary and tectono-magmatic development of the Izu–Bonin outer forearc region. The oceanic basement of the Izu–Bonin forearc was created by supra-subduction zone seafloor spreading during early Eocene (c. 50–51 Ma). Seafloor spreading created an irregular seafloor topography on which talus locally accumulated. Oxide-rich sediments accumulated above the igneous basement by mixing of hydrothermal and pelagic sediment. Basaltic volcanism was followed by a hiatus of up to 15 million years as a result of topographic isolation or sediment bypassing. Variably tuffaceous deep-sea sediments were deposited during Oligocene to early Miocene and from mid-Miocene to Pleistocene. The sediments ponded into extensional fault-controlled basins, whereas condensed sediments accumulated on a local basement high. Oligocene nannofossil ooze accumulated together with felsic tuff that was mainly derived from the nearby Izu–Bonin arc. Accumulation of radiolarian-bearing mud, silty clay, and hydrogenous metal oxides beneath the carbonate compensation depth (CCD) characterized the early Miocene, followed by middle Miocene–Pleistocene increased carbonate preservation, deepened CCD and tephra input from both the oceanic Izu–Bonin arc and the continental margin Honshu arc. The Izu–Bonin forearc basement formed in a near-equatorial setting, with late Mesozoic arc remnants to the west. Subduction-initiation magmatism is likely to have taken place near a pre-existing continent–oceanic crust boundary. The Izu–Bonin arc migrated northward and clockwise to collide with Honshu by early Miocene, strongly influencing regional sedimentation.  相似文献   

Geochemical characteristics of Proterozoic granite magmatism from Southern Granulite Terrain,India: Implications for Gondwana     

T Yellappa  J Mallikharjuna Rao 《Journal of Earth System Science》2018,127(2):22

Granitoid intrusions occur widely in the Southern Granulite Terrain (SGT) of India, particularly within the Cauvery Suture Zone (CSZ), which is considered as the trace of the Neoproterozoic Mozambique ocean closure. Here we present the petrological and geochemical features of 19 granite plutons across the three major tectonic blocks of the terrain. Our data show a wide variation in the compositions of these intrusions from alkali feldspathic syenite to granite. The whole rock geochemistry of these intrusions displays higher concentrations of \(\hbox {SiO}_{2}\), FeO*, \(\hbox {K}_{2}\hbox {O}\), Ba, Zr, Th, LREE and low MgO, \(\hbox {Na}_{2}\hbox {O}\), Ti, P, Nb, Y and HREE’s. The granitoids are metaluminous to slightly peraluminous in nature revealing both I-type and A-type origin. In tectonic discrimination plots, the plutons dominantly show volcanic arc and syn-collisional as well as post-collisional affinity. Based on the available age data together with geochemical constrains, we demonstrate that the granitic magmatism in the centre and south of the terrain is mostly associated with the Neoproterozoic subduction–collision–accretion–orogeny, followed by extensional mechanism of Gondwana tectonics events. Similar widespread granitic activity has also been documented in the Arabian Nubian shield, Madagascar, Sri Lanka and Antarctica, providing similarities for the reconstruction of the crustal fragments of Gondwana supercontinent followed by Pan-African orogeny.  相似文献   

Reliability of reanalyses products in simulating precipitation and temperature characteristics over India     

Nikhil Ghodichore  R Vinnarasi  C T Dhanya  Somnath Baidya Roy 《Journal of Earth System Science》2018,127(8):115

Various reanalyses have been utilized in numerous climate related researches around the globe, however, there exists considerable biasedness in these products, especially in precipitation and temperature data. The ability of these reanalysis products to simulate the precipitation and temperature patterns is observed to be satisfactory at global scale, while it differs significantly at regional scale, especially over regions of high spatio-temporal heterogeneity such as India. Therefore, it is essential to evaluate the applicability and robustness of reanalyses in climate related research. The annual and seasonal variability in spatio-temporal patterns and trends of precipitation and temperature data, with respect to the IMD gridded data over 34 yrs, are evaluated for six global reanalyses namely, NCEP/NCAR Reanalysis (NCEP R1), NCEP-DOE AMIP-2 Reanalysis (NCEP R2), Climate Forecast System Reanalysis (CFSR), ECMWF Interim Reanalysis (ERA-Interim), Modern Era Retrospective Analysis for Research and Application Land only model (MERRA-Land) and JMA 55-year Reanalysis (JRA-55). The ability of the reanalyses was tested based on several factors such as statistical and categorical indices, spells and trends, for annual and seasonal daily values. Several regional and seasonal differences were observed, particularly over high rainfall regions such as Western Ghats and northeastern India. MERRA-Land is found to give the best results for precipitation over India, which is attributed to the updated forcing data using gauge-based precipitation observations. Similarly, ERA-Interim and JRA-55 exhibit better performance for temperature than other datasets. All reanalyses failed to correctly reproduce the trends in IMD data, for both precipitation and temperature. These observations will provide a better perception on the reliability and applicability of reanalyses for climate and hydrological studies over India.  相似文献   

Benthic and Plankton Foraminifers in Hydrothermally Active Zones of the Mid-Atlantic Ridge (MAR)     

T.?A.?KhusidEmail author  N.?S.?Os’kina  N.?P.?Lukashina  I.?F.?Gablina  N.?V.?Libina  A.?G.?Matul 《Stratigraphy and Geological Correlation》2018,26(1):109-120

Comparison of benthic foraminiferal assemblages from the core obtained within the Peterburgskoe ore field (Mid-Atlantic Ridge) and from the core taken five kilometers away from the ore field revealed evident differences in their composition, in the appearance of their shells, and also in the benthic–plankton species ratio. It was noted that the foraminiferal assemblage from the ore-bearing sediments of the Petersburg field was characterized by a higher relative content of benthic species and a large number of chemically altered and broken shells. The first occurrence of the species Osangularia umbonifera, which is able to exist in lowoxygen and CaCO₃-undersaturated bottom waters at the boundary of biogenic sediments surrounding the ore field and in the ore-bearing sediments, was established. In the core section sampled beyond the ore field, the composition of foraminiferal assemblages differs insignificantly from typical oceanic ones.  相似文献   

Biostratigraphy and Sedimentary Settings of the Middle Devonian Succession of the Yuryung-Tumus Peninsula,Khatanga Gulf of the Laptev Sea     

N. V. Sennikov  T. A. Shcherbanenko  I. V. Varaksina  N. G. Izokh  E. S. Sobolev  A. Yu. Yazikov 《Stratigraphy and Geological Correlation》2018,26(3):267-282

The age of the Paleozoic sedimentary successions of the Yuryung-Tumus Peninsula in the Khatanga Gulf is determined as Middle Devonian, late Eifelian, and the beginning of the early Givetian on the basis of the study of brachiopods, ammonoids, nautiloids, bactritoids, gastropods, and conodonts, and in the terminology of the standard conodont succession, these deposits are not older than the late Eifelian Tortodus kockelianus Zone, but include the terminal Eifelian Polygnathus ensensis Zone and the first Givetian Polygnathus hemiansatus Zone and are no younger than the beginning of the early Givetian Polygnathus varcus Zone. The Middle Devonian sedimentary successions of the Yuryung-Tumus Peninsula show the level of the global sedimentary Ka?ak Event. The areas of distribution of the Devonian sedimentary deposits in the Yuryung-Tumus Peninsula in the Khatanga Gulf should be considered as one of the fragments of the regional geological structures of a remote (isolated?) region of the Taymyr Fold System rather than a component of the structures of the northern Siberian Platform.  相似文献