阿尔金构造系渐新世—中新世以来断裂左旋位错时空分布规律研究

A STUDY ON SPATIAL TEMPORAL DISTRIBUTION OF THE FAULT SINISTRAL DISPLACEMENT IN THE ALTUN STRUCTURE SYSTEM SINCE OLIGOCENE MIOCENE

组成阿尔金构造系的断裂，均具左旋位错特征。发生于渐新世—中新世以来的总位错量４５０～７００ｋｍ。其中，分布于阿尔金断裂带上的位错量达２２５～３７５ｋｍ，分布于其它断裂带上的位错量达１５０～２５０ｋｍ。发生于上新世以来的总位错量为９０～１３０ｋｍ。其中，分布于阿尔金断裂带上的位错量为５０～８０ｋｍ，分布于其它断裂带上的位错量为４０～５０ｋｍ。发生于第四纪的左旋位错量２０～２７ｋｍ。其中，分布在阿尔金断裂带上的位错量为７～１７ｋｍ，分布于其它断裂带上的位错量为１０ｋｍ左右。

The Altun structure system is a structure domain that consists of a set of monomict structures which have consistent strike, slimiar active character and origin connection. Many different geological units and a series of approximately parallel faults are involved in the Altun structure system. In the Altun structure system, all faults have sinistral displacement. Since Oligocene Miocene, sinistral displacement and slip rate for the the Altun structure system are 450～700km (average displacement is 580km) and 15mm/a, respectively. In the same period, displacement in the Altun fault zone is about 225～375km (average value is 300km), the left lateral slip rate is about 7mm/a. The displacement and slip rate for other faults in the Altun structure system are 150～250km (average displacement is about 200km) and 5mm/a, respectively. Since Pliocene, sinistral displacement and slip rate are 90～130km (average displacement is about 110km) and 11mm/a, respectively. For the Altun fault zone, left lateral displacement and slip rate are 50～80km (average is about 65km) and 6～7mm/a, respectively. For the other faults in the Altun structure system, sinistral displacement and slip rate are 40～50km (average is 45km) and 4mm/a, respectively. Since Quaternary, sinistral displacement and slip rate are 20～27km (average is 23.5km) and 9～12mm/a, respectively,. For the Altun fault zone, left lateral displacement and slip rate are 7～17km (average is 12km) and 5～7mm/a, respectively. For the other faults in the Altun structure system, left lateral displacement and slip rate are about 10km and 4～5mm/a, respectively. From Oligocene to Quaternary, the left lateral slip rate of the Altun structure system and the faults in system became slow down. The left slip rates get smaller from south to north. For the Altun fault zone, the displacment in the middle segment is larger than the two sides in Quaternary. It means that the left displacement reduced from the middle to two sides of the Altun fault zone.