THE EVOLVEMENT OF MESOZOIC AND CENOZOIC MAGMA IN NORTH TIBET: The significance to geodynamic diagenetic mineralization of gold

The magmatic activity during Messozoic and Cenozoic eras in north Tibet is intense, with a complex diagenetic mechanism. Study on the granites shows that the large batholith in the area is composed of rock units of various diagenetic environment and mechanism. Each unit has defferent relations to gold deposit. The spatial distribution of gold deposits is closely related to that of the rock bodies. Based on the study of major elements and Sr and O isotope of granite, the diagenetic tectonic setting, material resources and gold mineralization of the rock bodies present periodical (pulsing) changing with the diagenetic periods. There is a regular variation between crust thickness and gold mineralization while the igneous rocks formed.