Reflections on the rigidity of the Lut Block and recent crustal deformation in eastern Iran

Abstract

Imagery from the first Earth Resources Technology Satellite passes over east-central Iran are interpreted with special emphasis on geomorphology of the structural trends in the area. Several units of arcuate structure are named and discussed. Newly found dislocations and other lineaments within the Lut Block, in addition to its internal seismicity and Quaternary volcanic activity, support the argument against the rigidity of the block. Neotectonic and seismotectonic maps of the area are prepared and discussed. These maps reveal a complicated and mostly radial pattern of the pre-Neogene compressive directions. The post-Neogene directions of compression are, however, consistent with a NE—NNE trend throughout the area. These axes of maximum horizontal shortening are deduced from the trend of normal and en-echelon Neogene folds, the pattern and sense of movement of faults active in Quaternary, geodetic measurements, and the source mechanism of earthquakes. It is concluded that the plate-tectonic concept cannot readily be used to explain the recent deformation taking place in continental area structurally as complicated as eastcentral Iran.