Geomorphic indications of buried oil and gas-bearing structural landforms at southern Orenburg region

Abstract

Morphostructural framework of the region consists of arcuate and sub-rectilinear morpholineaments which indicate fault and fracture zones active during the neotectonic stage. They control boundaries of neotectonic block morphostructures differing in altitude, as well as outlines of ring structures. When morphostructures had been compared with data on deep structure of the area, it appeared that local elevations within the under-salt sedimentary cover (which are known or presumed to contain oil and gas) are located either within neotectonic subsidence areas near fault zones or within slightly elevated nlorphoblocks; they are mostly situated near points where arcuate morpholineaments (delineating large ring structures) cross regional sub-rectilinear lineaments. Such a morphostructural position should be considered as a geomorphological criterion of not yet identified buried structural forms promising for the oil and gas searches.