Some results of the palaeontological and stratigraphical researches of the Devonian sedimentsin the North Minusinsk depression

Tomsk State University (ТSU) professors drew quite interesting results on the palaeontology and stratigraphy of the Devonian sediments in the North Minusinsk depression. Some theoretical and practical scientific problems have been successfully solved. One problem was to define the age of the Byskar series sediments. The internal structure of the Byskar series is very complex; there is a significant number of stratigraphical schemes. At the first stages of studying the Byskar series, its age was accepted as Early-Middle Devonian. Researchers from ТSU have found out, that a section of the Byskar series around Shira settlement has trinomial construction - Lower Matarakskaya stratum (tuffs, lava breccias, trachyte andesites with layers of tuffogenous sandstones, etc. The Pridorozhnaya stratum, allocated by N.A. Makarenko, is divided into three packs. It is interbedded multicoloured sedimentary and volcanic rocks - conglomerates, sandstones, siltstones, and beds of trachyte basalts, and tuffs. Marchengashskaya stratum composed of basalts and trachyte basalts finishes the section. All the deposits of the series are bent in folds of different kinds and complicated by tectonic intrusions. The substantiation of the geological age of the allocated strata was done by studying the numerous finds of propteridophyte (psilophyte) flora by Professor A.R. Ananiev. The remains of the flora have been found along all the section. The hiatus in sedimentation during the Eifelian stage in Northern Khakassia and the Byskar series' Early Devonian age has also been proved. We offer an original scheme of correlation of the Matarak-Shunet and the Shira-Marchengash sections, based on comparing the marking tuff horizons. Two years ago A.L. Arkhipov found a new location of Late Devonian Archaeopteris flora (seed ferns) at Lake Oshkol. Together with fragments of sprouts and leaves, trunks of 10 cm in diameter have also been found nearby. This plant complex was found at the deposits of the Late Frasnian Kohayskaya suite. S.A. Rodygin found some specimens of Osteostraci of Ilemoraspis kirkinskayae Obruchev type in the Lower Devonian sediments on the territory of the training ground in 2004. This find is the second in Khakassia and the first in its northern part. The first time Discovery of a new locality of Osteostraci in Northern Khakassia has yielded a number of exceptionally well-preserved specimens of the genus and, subsequently, new texture information

Keywords

Authors

References