PRELIMINARY STUDY ON THE DEEP GEOLOGICAL STRUCTURE IN THE XUEFENG AREA(THE JIANGKOU—DONGKOU SECTION)

In accordance with the data of deep seismic sounding,MT sectional structure,gravitymodel of the continental crust in the Xuefeng Area,as well as the interactive comprehen-sive interpretation and understanding of the field observations in the area,a series of mapsconcerning about the geometry of deep crustal structures and median rocks are preliminari-ly compiled in this paper.It is concluded as:(1)The Proterozoic underplating"drifted"micro-continental blocks(or sea mounts),and tectonomagmatic(metamorphic)dikeswarms formed under Palaeozoic collision and epeirogeny,and ductile(or brittle)pyroliticmasses accompanied with the Meso-Cenozoic intracontinental subduction must be occurredin the area.(2)Both the Paleozoic"mildly sutured"structure and the Meso-Cenozoic"in-tra-crustal squeeze"which were dominated by two different dynamic systems must havetaken place.(3)A group of deep-shallow thrusting sheets and asymmetric deformationfan-tectosomes is a key tectonic(division)domain in S.China orogenic zone.