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961.
Natural Hazards - Worldwide coastal zones present serious erosion problems that cause loss of territory. This phenomenon exposes people and goods to the threat, being necessary to carry out a... 相似文献
962.
O. Mülayim I.O. Yilmaz B. Sari B. Ferré 《Proceedings of the Geologists' Association. Geologists' Association》2021,132(2):188-198
A ‘filament’ event bed/level corresponds to the occurrence of thin elongate calcitic, shells, or plates of pelagic, bivalve or crinoidal, origin, within pelagic, laminated and organic-matter rich limestones. These organic-rich limestones had been generally deposited under hypoxic/anoxic conditions in an outer-ramp environment. These thin elongate, bivalve shells, or crinoidal plates, are found broken in small pieces, disintegrated, or simply preserved parallel to bedding as almost complete specimens. Such ‘filament’ beds were spotted in SE Turkey in deposits, namely the Karababa-A Member, around the Cenomanian-Turonian boundary (C/TB) and above. On a global scale, these filament event beds illustrate sea-level rise related to eustacy and/or climatic change. The abundance of filaments close to the C/TB is a biological marker of high organic productivity resulting from a climatic change to warmer conditions. The prevailing higher sea-level conditions were then favourable to the accumulation and preservation of organic-rich facies, characteristic of the Oceanic Anoxic Event 2 (OAE2). Using both biostratigraphic and carbon isotopic data, those deposits were dated from the latest Cenomanian-Turonian age. ‘Filament’ event beds were recorded in the same order, except for some small differences. A good number of these bio-events are global. Consequently, on a global scale, they are susceptible to constrain the C/TB, especially the base of the Turonian stage, with a significant degree of confidence. 相似文献
963.
B.M. Besly C.J. Cleal 《Proceedings of the Geologists' Association. Geologists' Association》2021,132(1):50-65
An extensive regional stratigraphic hiatus has been proposed in the Asturian to Stephanian foreland basin successions lying to the north of the main Variscan deformation belt, stretching from north west Europe to eastern North America. The hiatus is inferred on megafloral grounds and involves the absence of most if not all of Stephanian Substages B and C. If present it would have great significance for the understanding of regional basin dynamics in the later stages of the Variscan orogeny. However, its existence has been strongly contested. One of the keys to this hypothesis is the correct identification and interpretation of plant fossils from the Warwickshire Coalfield (Central England). The published identifications are here shown to be incorrect, and revised determinations taken in conjunction with other stratigraphic data from Central England suggest that a regional hiatus is not present in the early-mid Stephanian, and that any stratigraphic hiatuses at other horizons in the succession are of purely local extent. A review of known occurrences of the Asturian and Stephanian successions in basins stretching from eastern Canada to Germany suggests that, while facies developments may be similar, there is little uniformity in stratigraphic style and little evidence for a major Stephanian hiatus. 相似文献
964.
Khotylev A. O. Mayorov A. A. Khudoley A. K. Ershova V. B. Kalmykov G. A. Khubanov V. B. Chervyakovskaya M. V. 《Geotectonics》2021,55(2):219-239
Geotectonics - In our research we summarized data obtained on the composition, structure, and geochemical characteristics of the granitoid plutons of the eastern part of the Krasnoleninsky arch of... 相似文献
965.
966.
Trifonov V. G. Sokolov S. Yu. Bachmanov D. M. Sokolov S. A. Trikhunkov Ya. I. 《Geotectonics》2021,55(3):334-360
Geotectonics - Studies carried out by the authors show that the uplift of Central Asia situated between the eastern Alpine–Himalayan and western Altai–Stanovoy orogenic belts formed in... 相似文献
967.
Sokolov S. D. Tuchkova M. I. Ledneva G. V. Luchitskaya M. V. Ganelin A. V. Vatrushkina E. V. Moiseev A. V. 《Geotectonics》2021,55(5):697-716
Geotectonics - The South Anyui Fold System was formed at the end of the Early Cretaceous at the site of a closed oceanic basin as a result of the collision of the Chukotka microcontinent with the... 相似文献
968.
Marrapu Balendra M. Kukunuri Anjana Jakka Ravi S. 《Geotechnical and Geological Engineering》2021,39(8):5879-5894
Geotechnical and Geological Engineering - Evaluation of slope stability using conventional limit equilibrium methods is very time consuming and repetitive, while the use of simplified approaches... 相似文献
969.
Goodman Zachary T. Stamatis Caitlin A. Stoler Justin Emrich Christopher T. Llabre Maria M. 《Natural Hazards》2021,106(3):2731-2749
Natural Hazards - Socially vulnerable communities experience disproportionately negative outcomes following natural disasters and underscoring a need for well-validated measures to identify those... 相似文献
970.
Geotechnical and Geological Engineering - Distribution constant, (Kc) is employed to account for desorption of water molecules from soil particles. When water molecules have strong affinity for... 相似文献