Triassic

Dedication to the memory of a colleague, Doctor of Geological and Mineralogical Sciences Valentin P. Tverdokhlebov, a well-known specialist in sedimentology and palaeogeography of the Late Permian and Triassic of the Eastern Russian Plate and Southern Urals, as well as taphonomy of vertebrate localities. Valentin Petrovich is a long-time head of the geological survey party investigating the stratigraphy of continental red-coloured strata, tectonics and placement of minerals in the Orenburg region.

Lithologies were examined of the cores from the deep wells that have penetrated the entire section of the Triassic system in the Pricaspian Depression; material compositions and accumulation peculiarities of the Triassic sequences have been revealed. Certain events have been found comparable to those in the North Germanic Depression.

Event stratification of the sections constitutes an investigation trend aimed at detailed interregional correlation of sedimentary sequences. Based on extensive factual material, the authors have revealed the most significant changes in the Middle Triassic sedimentary and volcanogenic-sedimentary bodies. The entire Middle Triassic is peculiar for manifestations of hydrothermal-metasomatic processes within terrigenous, biogenic, volcanogenic bodies and bodies of mixed origins.

In connection with Carboniferous, Permian and Triassic rocks, marked by magnetic susceptibility of thousand and dozens of thousands (10-5 SI units) that are located in southern part of Precaspian Depression, samples of these rocks were studied in details, using strongly magnetic samples. The possible effects of anomalous magnetic field were counted on the base of received data.

Indicators of sedimentogenesis have been established for paleogeographic reconstructions based on ecosystem-nanostructural analysis of finely dispersed sediments. The Early Triassic Olenekian sediments have disclosed some features of primary food chains peculiar for marine basins within the landscapes previously regarded as continental ones. Those have been classified as plains periodically flooded by sea. The coccolith- and ostracod-bearing sediments from epicontinental basins have been recorded in the Middle Triassic sections.

This paper presents a brief biography of the Professor Maxim G. Minich, a Soviet and Russian specialist in fossil fish and stratigraphy of the Permian and Triassic of the Russian Plate and the Cis-Uralian peripheral depression. He was a brilliant representative of the middle generation of the Saratov school of vertebrate researchers, the head of the Department of Biostratigraphy and Paleontology at the Scientific Research Geological Institute of Saratov State University and latterly its Director. He was an honorary member of the All-Russian Paleontological Society.