scholarly journals Facies and depositional environments of the Upper Muschelkalk (Schinznach Formation, Middle Triassic) in northern Switzerland

2019 ◽  
Vol 112 (2-3) ◽  
pp. 357-381 ◽  
Author(s):  
Arthur Adams ◽  
Larryn W. Diamond
Keyword(s):  
Middle Triassic ◽  
Depositional Environments ◽  
Northern Switzerland ◽  
Upper Muschelkalk

scholarly journals The Early to Middle Triassic continental–marine transition of NW Bulgaria: sedimentology, palynology and sequence stratigraphy

2018 ◽  
Vol 69 (2) ◽  
pp. 129-148 ◽  
Author(s):  
George Ajdanlijsky ◽  
Annette E. Götz ◽  
André Strasser
Keyword(s):  
Middle Triassic ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Stratigraphic Correlation ◽  
Carbonate Group ◽  
Meandering River ◽  
Reference Sections ◽  
Sequence Boundaries ◽  
Early Middle Triassic ◽  
Major Sequence

AbstractSedimentary facies and cycles of the Triassic continental–marine transition of NW Bulgaria are documented in detail from reference sections along the Iskar river gorge between the villages of Tserovo and Opletnya. The depositional environments evolved from anastomosing and meandering river systems in the Petrohan Terrigenous Group to mixed fluvial and tidal settings in the Svidol Formation, and to peritidal and shallow-marine conditions in the Opletnya Member of the Mogila Formation. For the first time, the palynostratigraphic data presented here allow for dating the transitional interval and for the precise identification of a major sequence boundary between the Petrohan Terrigenous Group and the Svidol Formation (Iskar Carbonate Group). This boundary most probably corresponds to the major sequence boundary Ol4 occurring in the upper Olenekian of the Tethyan realm and thus enables interregional correlation. The identification of regionally traceable sequence boundaries based on biostratigraphic age control is a first step towards a more accurate stratigraphic correlation and palaeogeographic interpretation of the Early to early Middle Triassic in NW Bulgaria.

Syzygial brachials from the upper Muschelkalk (Middle Triassic, Ladinian) of Poland and their implication for an early origin of comatulid crinoids

2008 ◽  
Vol 82 (3) ◽  
pp. 634-637 ◽  
Author(s):  
Mariusz A. Salamon ◽  
Michat Zatoń ◽  
Przemysław Gorzelak
Keyword(s):  
Middle Triassic ◽  
Upper Muschelkalk ◽  
Early Origin ◽  
Irregular Arrangement

According to Ubaghs (1978), syzygies are brachial articulations in which radiating ridges and furrows on the two joint faces oppose each other rather than interlock as in symplexies. Cryptosyzygies differ from syzygies by having very short ridges that may be replaced by rows of tubercles or granules, with a tendency toward irregular arrangement and disappearance. Among Triassic crinoids, only representatives of the orders Isocrinida Sieverts-Doreck, 1952 and Comatulida Clark, 1908 had cryptosyzygial or syzygial brachial articulation, respectively. According to Rasmussen (1978), among Isocrinidae the articulations of primibrachial 1 and 2 and secundibrachial 1 and 2 were cryptosyzygial or synarthrial (but see also comments in Simms, 1988a). Among Comatulida, syzygial articulations generally occur between brachials 3 and 4 and in more distal arm parts.

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