Taduesz Ziętara

Abstract

The Khentei mountain massif is situated between the mountains of the SouthSiberian Mountains and Central Asian Plain.

The study area is situated within the Khentei block, which is part of a Paleozoicfolded system. The Khentei block is bounded by deep disrupted faults. There aregeosynclinal flysch metamorphic and deformed Paleozoic deposits in the Hercinianand Caledonian orogeneses (Klimek, Ziętara and Tserensodnom 1980). At that timethere appeared granitoid intrusions connected with belts of deep disruptions. Due tothe appearance of abyssal fissures and to the block uplifting of some sites and tothe massive magmatism, the huge synclinorium underwent a fundamental deformationto yield a varied orogen (Klimek, Ziętara and Tserensodnom 1980; Malarz1980) which is dominated by large tectonic dislocations.

This paper deals with the results of research on contemporary geomorphologicalprocesses. The research was carried out in 1975 and 1977 during the Mongolian-Polish Physical-Geographical Expeditions organized by the Polish and MongolianAcademies of Sciences.

Geomorphological explorations in different climatic zones were conducted mainlyby geomorphological mapping (Fig. 1), at scales 1 : 100 000 and 1 :25 000. Attemptwas made to show relief correlation with geological structure and to define maindevelopment stages associated with climatic variations. In order to evaluate thecontemporary relief transformation a map of present-day geomorphological processesfor the entire basin was prepared and morphoclimatic zones were distinguished.

The differentiation of landscape belts is related to climatic conditions. Meantemperatures of the warmest month (July) range from 15°C in the middle stretchof the valley to about 5°C in its upper regions (Brzeźniak and Malarz 1980). Insummer pronounced thermic inversion is observed in valley bottoms. The yearlyprecipitation total on the foothills amounts to 250-300 mm and increases to 500 mmon the Baga-Khentei ridges. The heaviest and frequently occurring precipitation isobserved in summer towards the end of June and in July. During our stay in theregion the precipitation totals were 88 mm in the middle and 133.8 mm in the upperareas of the Sugnugurin-gol valley. In winter a continuous snow cover persists, itsthickness increase with the altitude. The thickness and duration of snow coverdepends on the morphology and aspect of the slopes. On north-east slopes patchesof snow survive in the taiga till around the middle of June, while in the tundrathey are still found towards the end of July.

Taduesz Ziętara, College of Pedagogy, Cracow. Poland