FORMATION AND EVOLUTION OF THE LUONAN-LUANCHUAN FAULT BELT IN THE EAST QINLING REGION

On basis of investigation of the structural characteristic,study of geophysical behavior and analysis of evolution history of the Luonan—Luanchuan fault belt,it was considered that the fault was long lasting lithosphere fault between the North China Plate and the northern Qinling orogenic belt.It controled development of the Luonan—Luanchuan and Yunjiashan-Erlangping fault basins during the Proterozoic to the Early Ordovician.The fault was thrusted from south to north during the Silurian to the Devonian,and it was not active in the Late Paleozoic.The front zone of the orogenic belt was conti-nuously advanced toward to the north during the Middle Triassic to the Early Cretaceous.The pull apart basins were developed along the Luonan-Luanchuan fault belt under background of right slip movement in the northern Qinling area during the Late Cretaceous.