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. Jacquin , T. , P.-C. de Graciansky 1998 : Major transgressive/regressive cycles: the stratigraphic signature of European basin development . — In: de Graciansky , P.-Ch. , J. Hardenbol , Th. Jacquin , P.R. Vail (eds): Mesozoic and Cenozoic
Transgressive-regressive cycles and Jurassic palaeogeography of northeast Iberia Sedimentary Geology 162 239 271 . B
deposited from slackwater fallout and deposited on the top of the Tournaisian unit. Fig. 4. Sedimentary structures of estuary/lagoon depositional environment in the transgressive cycle A: microlaminated mudstone and siltstone with horizontal and wavy
67 1 11 . D.A. Ruban 2007 Jurassic transgressions and regressions in the Caucasus (northern Neotethys Ocean) and their
The Senonian succession of the Szilvágy-33 well in the Northern Zala Basin was investigated in order to re-evaluate its chronostratigraphic subdivision and depositional history. The studied sequence begins with the Ajka Formation of reduced thickness and atypical facies. This is followed by the Jákó Formation with the interfingering layers of the Ugod Limestone, and then the approximately 300 m-thick section of the Ugod Limestone which is covered by the Polány Marl. According to the palynologic and nannoplankton investigations, the entire encountered sequence can be assigned to the Campanian. The layers assignable to the Ajka Formation contain the sporomorph assemblage known from the upper section of the Jákó Formation in the Bakony basins, clearly indicating a considerable temporal shift of the lithofacies during transgression. The late transgression demonstrated in the Szilvágy-33 well suggests an elevated paleotopography. In contrast to the former assumptions, the transgression may not have reached the Bakony region via the Zala Basin; rather, both sub-areas were invaded by the sea from the South Alpine pelagic basins.
Abstract
Analysis of continental-scale lithostratigraphic data may facilitate an understanding of global sedimentary processes. The number of carbonate-bearing formations established in northern Eurasia (430 in total), northern Africa and Arabia (47 in total), and India (98 in total) is calculated per epochs for the last 145 Ma. The results show maxima in the Late Cretaceous, the Eocene, and the Miocene and minima in the Paleocene, the Oligocene, and the Pliocene. The Quaternary records are somewhat ambiguous. The similarity of the patterns established in the three regions argues for a single globalscale mechanism of carbonate accumulation. The noted patterns also coincide well with some modeled changes in the global amount of carbonates accumulated by epoch. Moreover, increases in the amount of carbonates in the Late Cretaceous and the Eocene, and a decrease in the Paleocene, reflect true changes in the accumulation rates. The global process of carbonate accumulation might have been controlled, at least, by eustatic changes (sea-level rise led to broad transgressions on continental margins and consequently to expansion of shelfal paleoenvironments) and climate dynamics (warm water facilitated carbonate production). Interestingly, no dependence between the global carbonate accumulation and marine biodiversity dynamics is established.
Abstract
Two depositional megasequences of the Karst Dinarides that record two different, emersion-separated, depositional periods are presented; the older lasted from the upper part of the Middle Permian to the Middle Triassic, and the younger one from the Late Triassic to the Late Cretaceous. Both megasequences are typified by shallow-water platform deposits; the earlier megasequence formed under epeiric carbonate/clastic platform conditions and the later one under isolated carbonate platform conditions. Significant geodynamic movements within the southern Tethys realm led to Middle Triassic tectonic uplift, i.e. to the emersion of the huge platform area where a regional unconformity between two platform megasequences was formed. Four types of terrestrial phase horizons are identified, each representing different subaerial conditions that existed during the long-lasting emersion. These are: a significant disconformity and related stratigraphic gap between the Upper Scythian and Lower Norian; a tuffaceous horizon between the Upper Anisian and Lower Norian; an Upper Ladinian-Upper Norian brecciated horizon; and an Upper Ladinian-Lower Norian claystone/bauxitic horizon. Due to the widespread diachronous transgression during the Norian, shallow-water platform sedimentation was restored over the entire emergent area, initiating a long-lasting isolated carbonate platform regime.
Abstract
The formations of the Balaton Highland provide a high-resolution record of various fossil groups (ammonoids, bivalves, brachiopods) from the Early Triassic to the Carnian, with remarkable changes in taxonomic diversity. The local data differ considerably from the gradually increasing global diversity trends of the respective fossil groups. Ammonoids are rare in the Early Triassic; during the Anisian they reach a diversity maximum and remain rather diverse until the Carnian. This is connected to the considerable deepening of the sedimentary basin in the Middle Triassic. The benthic fossil groups show almost inverse local trends. In the Early Triassic, the proliferation of bivalves largely follows the transgressive pulses in the shallow marine setting; brachiopods are represented solely by Lingula specimens. Both the bivalve and the brachiopod diversity culminate in the middle Anisian what is interpreted in terms of extensional tectonic movements: the rocky escarpments of the disintegrated carbonate platforms provided favorable biotopes for sessile benthic organisms. The benthic diversities decreased significantly in the rest of Middle Triassic, which is due to the significant deepening of the local basin floor. The benthic groups reached maximum diversity in the Carnian. This is attributed partly to the filling up and shallowing of the local basin, partly to redeposition in the course of platform progradations, carrying rich fossil shell material from the neighboring shallow marine environments to the basin. Simultaneously, the sudden increase of the humidity (“Carnian pluvial event”) created extensive river systems in the European continent; the increasing supply of organic matter was favorable for the benthos in the marine environments.
. 50 331 Swift, D., 1968: Coastal erosion and transgressive stratigraphy. Jour. Geol. , 76 , pp. 444-456. Coastal erosion and
. Geomorphology I (In Serbian). - Drzav. Štamp. 1 588 Vatsev, M. 2003: Oligocene and Neogene major transgressive-regressive cycles of the basins of Sredna Gora
