Structural characteristics of middle and southern Xainza-Dinggye Normal Fault System and its relationship to Southern Tibetan Detachment System

The Xainza-Dinggye Normal Fault System (XDNFS) is a large-scale nearly-north-south trending exten-sional structure across central and southern Tibet. Its middle segment developed in Tethys Himalaya with features of earlier magmatic core complex and later normal faults dipping moderately to northwest-west. The magmatic core complex is made up by mylonitic leucogrante with a low-angle detachment fault on the top of it and overlain by lower-grade meta-sedimentary rocks. The structural pattern of the southern segment of XDNFS take the shape of a detachment fault dipping to southeast-east with the High-Himalayan rock series as the lower plate. The Southern Tibetan Detachment System (STDS) is expressed as a ductile shear zone composed of mylonitic leucogranite in the studied area of this note. STDS was cut by the later XDNFS, which presents that nearly-east-west striking STDS is not the controlling or adjusting structure of the nearly-north-south trending ex-tensional structures. The origin of

The Xainza-Dinggye Normal Fault System (XDNFS) is a large-scale nearly-north-south trending exten-sional structure across central and southern Tibet. Its middle segment developed in Tethys Himalaya with features of earlier magmatic core complex and later normal faults dipping moderately to northwest-west. The magmatic core complex is made up by mylonitic leucogrante with a low-angle detachment fault on the top of it and overlain by lower-grade meta-sedimentary rocks. The structural pattern of the southern segment of XDNFS take the shape of a detachment fault dipping to southeast-east with the High-Himalayan rock series as the lower plate. The Southern Tibetan Detachment System (STDS) is expressed as a ductile shear zone composed of mylonitic leucogranite in the studied area of this note. STDS was cut by the later XDNFS, which presents that nearly-east-west striking STDS is not the controlling or adjusting structure of the nearly-north-south trending ex-tensional structures. The origin of nearly-north-south trending extensional structures in Tibet may be the result of de-formational partition of north-south compression.