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Were Late Cretaceous extinctions of gastropods selective by generic longevity?

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Geoscience Frontiers 2013年第1期4卷 87-93页

作者： dmitry a.ruban Division of Mineralogy and Petrography Geology and Geography FacultySouthern Federal University

Many gastropod taxa went extinct during the Late Cretaceous. The stratigraphic ranges of 268 genera permit to establish the longevity of extinction victims for each stage of this epoch. ＂Young＂ taxa （originated within B epochs before the extinction） prevailed among victims of the extinctions in all stages. The proportion of ＂old＂ taxa （originated before the Cretaceous） that went extinct was the highest in the Cenomanian, and it was the lowest in the Coniacian and the Maastrichtian. It appears that the end-Cretaceous mass extinction affected chiefly ＂young＂ taxa. However, the comparison with the earlier time intervals suggests that this pattern of selectivity by generic longevity was not specific for the noted catastrophe, but, in contrast, it was typical for the entire Late Cretaceous. The latest Cenomanian environmental perturbation （OAE2） caused a stronger extinction of＂old＂ taxa, and thus, this biotic crisis was less selective by generic longevity. This hypothesis, however, is not proven by the statistical test.

关键词： Gastropods Extinction Longevity Selectivity Late Cretaceous

Episodic events in long-term geological processes:A new classification and its applications

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Geoscience Frontiers 2018年第2期9卷 377-389页

作者： dmitry a.ruban Southern Federal University 23-ja linija Street 43Rostov-na-Donu344019Russia

Long-term geological processes are usually described with curves reflecting continuous changes in the characteristic parameters through the geological history, and such curves can be employed directly for recognition of episodic(relatively long-term) events linked to these changes. The episodic events can be classified into several categories according to their scale(ordinary and anomalous events), "shape"(positive, negative, and neutral events), and relation to long-term trend change(successive, interruptive,facilitative, stabilizing, transformative, increasing, and decreasing). Many types of these events can be defined depending on the combination of the above-mentioned patterns. Of course, spatial rank,duration, and origin can be also considered in description of these events. The proposed classification can be applied to events in some real long-term geological processes, which include global sea-level changes,biodiversity dynamics, lithospheric plate number changes, and palaeoclimate changes. Several case examples prove the usefulness of the classification. It is established that the Early Valanginian(Early Cretaceous) eustatic lowstand(the lowest position of the sea level in the entire Cretaceous) was negative,but ordinary and only interruptive event. In the other case, it becomes clear that the only end-Ordovician and the Permian/Triassic mass extinctions transformed the trends of the biodiversity dynamics(from increase to decrease and from decrease to increase respectively), and the only Cretaceous/Paleogene mass extinction was really anomalous event on the Phanerozoic biodiversity curve. The new palaeontological data are employed to reconstruct the diversity dynamics of brachiopods in Germany(without the Alps) and the Swiss Jura Mountains. The further interpretation of the both diversity curves implies that the Early Toarcian mass extinction affected the regional brachiopod faunas strongly, but this event was only decreasing(biotic radiation continued after

关键词： Biodiversity dynamics Early Triassic warming Geological classification Plate tectonics Toarcian

Lagoonal carbonate deposition preceding rifting-related uplift:evidence from the Bartonian-Priabonian(Eocene)of the northwestern Gulf of Suez(Egypt)

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Journal of Palaeogeography 2022年第1期11卷 8-30页

作者： Emad S.Sallam dmitry a.ruban A.J.(Tom)Van Loon Department of Geology Faculty of ScienceBen ha UniversityFarid Nad a Street 15Ben ha 13518Egypt K.G.Razumovsky Moscow State University of Technologies and Management(the First Cossack University) Zemlyanoy Val Street 73Moscow 109004Russia c College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590ShandongChina

Sedimentary successions in the northwestern Gulf of Suez provide important clues to the understanding of the geological evolution of NE Africa during the middle and late *** study focuses on detailed facies analyses in order to characterize the depositional environments and system tracts of the Bartonian-Priabonian succession cropping out in this ***-Priabonian carbonate deposits in five stratigraphic sections constitute,from base to top,the Gebel Hof,Observatory,Sannur,Qurn,and Wadi Hof *** formations contain four local assemblage zones of larger benthic *** of litho-,bio-,and microfacies in the succession resulted in the recognition of 12 lithofacies *** lithofacies are represented by packages of lime-mudstones,wackestones,packstones,pack-to grainstones,grainstones,rudstones,boundstones and *** lithofacies have been grouped into four geneticallyrelated facies associations that represent,respectively,tidal flats/shallow subtidal,restricted-shelf/lagoonal,shoal bar,and outer-shelf lagoon/reefal depositional environments in a downslope shallow-marine inner-ramp *** vertical transitions of these facies associations,representing facies changes through time,imply fluctuations of the regional sea *** two peaks in the Bartonian correspond to well-known global eustatic sea-level rises;the pronounced Priabonian regression must be ascribed to the known global eustatic sea-level fall in combination with regional tectonic *** facies distribution suggests that the study area was located in the direct vicinity of some islands during the Bartonian-Priabonian.

关键词： Lagoonal facies Sea-level fluctuations Middle Eocene Late Eocene Eastern Desert

A Comparison of the Genetic Shaft Types of Some Karst Areas Based on Their Specific Shaft Lengths

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Journal of Geological Research 2019年第3期1卷 40-50页

作者： Márton Veress András Hegedűs Pavle Cikovac ruban dmitry A Kálmán Péntek Department of Geography Eötvös Lóránd UniversitySzombathelyHungary Duna-Ipoly National Park Directorate BudapestHungary Department of Geography Ludwig-Maximilians-University of MunichMunichGermany Southern Federal University Rostov-na-DonuRussia Department of Mathematics Eötvös Lóránd UniversitySzombathelyHungary

Shaft development can be documented on the basis of comparative studies of specific shaft lengths and shaft *** calculated the specific length of shafts and the average specific shaft length of the shafts in some karst areas and we investigated the relation between the altitude of shaft floors and the specific shaft *** the registered specific shaft lengths and the shaft patterns into consideration,it can be stated that some parts of the shafts developed paragenetically in the studied karst *** the Bakony Region,this was caused by surface water influx,rise of karst water level,and their simultaneous *** a result,shaft systems,bifurcating shafts and storeyed shafts *** glaciokarst areas,shafts may constitute a system with phreatic passages:either because a phreatic environment developed in the vadose zone due to the permanent impoundment of karst water or because a phreatic passage got into the vadose zone since the karst became *** the studied karst areas,the following shaft development types are distinguished:glacial-high mountain surface flood development type(1),glacial-high mountain karst water and surface flood development type(2),glacial karst water and surface flood later phreatic development type(3),shaft with a passage that got into the vadose zone(4).

关键词： Shaft Specific shaft length Shaft development Vadose zone Phreatic zone Glaciokarst