FOSSIL TRACES OF THALASSINOIDES FROM SEROV SUITE GAIZES (MIDDLE TRANS-URALS, UPPER PALEOCENE)

Abstract

The relevance of the research. In the northern margins of Western Siberia, depositional breaks are indicated in the sediments of Tanetian stage. Global nature of such hiatuses and possibility of their existence in the southern margins remain debatable. This requires the use of additional paleontological and sedimentological data that capture the crisis of the introduction of sedimentary material. One of the most reliable source of information about interruptions to introduction of sedimentary material and other events in sedimentation can be fossil burrows. The aim of the research is the ichnofacial analysis of siliceous sediments of the Upper Paleocene of Western Siberia. Objects: fossil traces of Thalassinoides from silica rocks Serov suite (Middle Trans-Urals, Upper Paleocene), burrow-filling rock (light gaize with a thin-globular structure), burrow-containing rock (dark gaize, represented by a structureless mass of silica) Methods: field work, scanning electron microscopy, lithologic-petrographic, ichno-structure, ichno-facies and sedimentological analyzes. Results. Information on fossil traces of Thalassinoides from Serov suite gaizes and fossil traces morphology are given. The paper considers the issues of possible environmental conditions, under which the burrow marks were formed and preserved in fossil state. Microscopic studies of Serov suite gaizes allow identifying the features of changes in rocks, that contain and fill burrows, during further diagenetic transformation. Also the article highlights the most likely producers for Thalassinoides burrows of Tanetian time in the West Siberian basin. The study of fossil traces in siliceous rocks of the Paleogene period has not been undertaken before and has not been noted in scientific literature.

Keywords

• fossil traces
• gaizes
• serov formation
• paleocene
• western siberia
• transuralian
• thalassinoides
• glossifungites