LAUSR

ABSTRACT This work presents a detailed report on the geological structure and resource potential of biosiliceous sedimentary rocks of Western Siberia. In terms of spatial distribution and resource potential, siliceous rocks are one of the main types of non-metallic mineral resources in the western and northern parts of West Siberia and are potentially highly prospective for regional industries. The sequence of siliceous rocks in this region was formed in a shallow transition epicontinental basin during the Palaeocene–Eocene. The main lithological varieties of these rocks include diatomites, diatomaceous clays, opoka, and tripoli. The near-surface bedding of siliceous rocks occupying a vast area from northern Kazakhstan to the Taz Peninsula indicates that the West Siberian Province is one of the largest regions of these raw mineral materials. Based on geologic, mining, and economic–geographic criteria, a new structural zoning of the West Siberian Province is proposed to include the Transuralian, Ob, and Nadym–Taz zones. The deposits in the Transuralian zone have horizontal and slightly inclined sheet-like bedding, the most favourable mining conditions, and a high degree of infrastructural development. The Ob and Nadym–Taz zones have a much more complex structure, where the rocks were exhumed by joint action of tectonic and denudation processes. Parallel-ridge relief reflects the deep structure of these zones. High heterogeneity of the strata and complex geocryological conditions help to constrain the development of siliceous rock deposits in northwestern Siberia. Permafrost-affected rocks are locally distributed in the Ob zone and are widespread in the Nadym–Taz zone. A high ice content in the rocks in the northern territories complicated the technological operations during the exploitation of deposits, storage, and processing of raw minerals, which hampered their development.