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First record of tempestites from Quaternary lacustrine deposits in the Ağrı Basin (Eastern Anatolia, Türkiye) : palaeoclimatological and palaeogeographic implications

Üner Serkan

Geological Quarterly

2023

Vol. 67, No. 2

art. no. 13

Several event layers have been identified in lacustrine deposits in the AErI Basin of Anatolia (E Türkiye). Sedimentological and palaeontological data newly indicate a storm-induced origin for some of them. The sedimentary structures in three sections, a few tens of metres apart from each other laterally, such as hummocky cross-stratification, wave-generated cross-bedding, parallel bedding, erosional surfaces, and graded bedding, which are considered characteristic of tempestites, are clearly present. Additionally, fining-upwards units and biogenic escape structures located at different levels of these sections indicate a similar origin. The vertical variations in layer thickness, grain size, and sedimentary structures in these sedimentary sections indicate fluctuating hydrodynamic conditions during deposition, while lateral decrease in the size and wavelength of the structures reflects deepening. This interpretation of storm-induced deposition is compatible with regional palaeoclimatological and palaeogeographical data, and is supported by evidence of Quaternary storm-induced sedimentation in adjacent lacustrine basins in the region.

Diversity of vertebrate remains from the Lower Gogolin Beds (Anisian) of southern Poland

Antczak Mateusz, Ruciński Maciej, Stachacz Michał, Matysik Michał, Król Jan J.

Annales Societatis Geologorum Poloniae

2020

Vol. 90, No. 4

419--433

Middle Triassic (Muschelkalk) limestones and dolostones of southern Poland contain vertebrate remains, which can be used for palaeoecological and palaeogeographical analyses. The results presented concern vertebrate remains uncovered at four localities in Upper Silesia and one on Opole Silesia, a region representing the south-eastern margin of the Germanic Basin in Middle Triassic times. The most abundant remains in this assemblage are fish remains, comprising mostly actinopterygian teeth and scales. Chondrichthyan and sauropsid remains are less common. Reptilian finds include vertebrae, teeth and fragments of long bones, belonging to aquatic or semi-aquatic reptiles, such as nothosaurids, pachypleusorosaurids, and ichthyosaurids. Also, coprolites of possibly durophagous and predacious reptiles occur. In the stratigraphic column of Mikołów, actinopterygian remains are the most numerous and no distinct changes of the taxonomic composition occur. Although this assemblage differs from those described at other localities (Ząbkowice with numerous chondrichthyans, Żyglin, and Płaza with common sauropsid fossils), sampling bias has to be considered.