东秦岭洛南—栾川断裂带的形成和演化

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

通过对洛南—栾川断裂构造特征的考察、地球物理特征的研究及其演化史分析,认为该断裂是一条长期发育的、位于华北地块与秦岭造山带之间的岩石圈大断裂。在新元古代—中奥陶世,其控制了洛南—栾川、云架山—二郎坪裂陷盆地的发育;志留纪末期—泥盆纪初,断裂由南向北逆冲推覆;晚古生代,断裂处于不活动状态;中三叠世末—早白垩世早期,造山带逆冲系前锋不断向北推进;晚白垩世,北秦岭地区处于右旋走滑背景,沿洛南—栾川断裂形成拉分盆地。

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 continuously 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.