PREDICTIVE ESTIMATE OF Ti-Zr PLACER DEPOSITS IN MESOZOIC AND CENOZOIC SEDIMENTS AT NW MARGINS OF THE ZAYSAN BASIN, EAST KAZAKHSTAN

Abstract

During the research of orographic, geological and geomorphological characteristics of the Zaysan basin area aiming to identify targeting factors of Ti-Zr alluvial deposits it has been established that the following special favourable conditions are required for their formation: neighbouring occurrence of magmatic rocks with Ti-Zr credit; well-formed deep chemical weathering crust, which has facilitated the release of ore minerals; alluvial, proluvial limnic hydrodynamic conditions for transportation, segregation and concentration of Ti and Zr minerals; availability of local structural particular qualities (tectonic layers, basins), which have prevented the deposits from washing out during transgression and regression of the Zaysan paleo-lake. It has been established that well-known Ti-Zr deposits in the north-west margin areas of the Zaysan basin are geomorphologically located in gentle slope, non-segmented plains of subaerial denudation of 400–700m altitude, within the littoral zone of the Zaysan paleolake. The orographic representation of modern relief of the region have been established, stratigraphic positions of Mesozoic and Cenozoic placer deposits were determined, and an area for prospecting of new Ti-Zr deposits was identified.