CONTEMPORARY TECTONIC STRAIN RATE FIELD OF CHINESE CONTINENT AND ITS GEODYNAMIC IMPLICATIONS

摘要: We obtain contemporary tectonic strain rates of Chinese continent from analyzing crustal motion inferred GPS velocity field. Our result shows that driven by the northward indentation Indian plate, Tibetan plateau and its vicinity areas undergo extensive deformation, rather than concentrated along narrow deformation zones a few large-scale strike-slip faults delineating boundaries; this field is broadly distributed within plateau, possibly different mechanisms region to region. The rate in southern Tibet appears be north-south compression east-west extension, at about 2×10 -8 -1 for both components. This could thickening lithospheric delamination, resulting decoupling upper crust mantle.This produce eastward ductile flow lower responding causing tension crust.The Qiangtang region, central Tibet, also nearly equal amount NNE NWW extension , reflecting active faulting group conjugate oriented northeasterly northwesterly, resulted asthenosphere. Qaidam basin have northeast direction (0~1)×10 northwest direction.This pattern suggests temperature increase not enough cause full between crust, thus it less efficient accommodate shortening through (i.e. crust) folding thrusting weak zones). conclude has been progressive development south north, systematic differences regional structures,which affect driving consequently.