| Abstract:Based on the data obtained in field survey, we have divided the Sanjiang region into three large tectonic elements, i.e. , the western margin of Yangtze plate, the northeastern margin of Indian plate and the connective or transitional belt between them. Especially in the last belt, several ophiolite zones are developed as remains of the paleo-Tethys oceanic crust; late Variscan trench-arc systeIn, Indosinian trench-arc-basin system and their corresponding deposition zones can be observed clearly. Another important feature lies in the existence of quite a few stratigraphic and metamorphic blocks of different ages among those zones, which have been turned into elongated and lozenge-shaped bodies of different sizes as a result of late compression and shearing.Based on the newly-divided geotectonic framework and the internal relations between the metallogenic formation and the tectonic evolution, 11 major metallogenic zones are recognized in Sanjiang region. A study of the relationship between tectonic evolution and mineralization has led us to divide the ore-forming process into six major ore-forming stages, namely pre-TethyS, paleo-Tethys, collision, post-collision, Meso-Tethys, and inner-continental extrusion. This paper also emphatically describes styles of tectonic movement and tectonic deformations related to mineralization such as splitting-seafloor spreading, subduction, collision, ductile shearing, napping and strike-slip faulting. |
