Abstract:
The northwest margin of the Junggar Basin in Xinjiang belongs to the Central Asia orogenic metallogenic belt, which is one of the important copper polymetallic metallogenic belts in China. The study of the genesis and ore bearing properties of the intrusive rocks in the area has important practical significance for further improving the degree of geological and mineral exploration in the area. Based on the study of its geological characteristics and mineralization occurrence characteristics, Jieledikezeng diorite sequence in Tacheng, Xinjiang, has been systematically sorted and analyzed by using its rock geochemical data. Combined with the previous chronological data, the rock genesis, tectonic environment, ore bearing property and its relationship with mineralization of this rock mass have been preliminarily discussed, providing some basic references for geological prospecting in this area. Jieledikezeng diorite sequence in Tacheng, Xinjiang is composed of four intrusive periods, namely, gray fine-grained diorite porphyrite, coarse-grained diorite porphyrite, fine medium grained diorite and gray white biotite quartz diorite.The rock mass is low in silicon, magnesium and potassium and high in sodium, aluminum and iron; weakly quasi aluminous, subalkaline series rocks; Rb, Ba, Th and other large ion lithophile elements are enriched, while Nb, Ta, Y, Yb and other high field strength elements are depleted; the rare earth content is low, and the distribution pattern shows a right leaning curve.It is a light rare earth enriched rock, There is weak loss anomaly of cerium and europium.The intrusive diagenetic age of the rock mass is the end of the Early Carboniferous, formed in the island arc tectonic environment, and belongs to the pre orogenic I-type Cordillera granite, Its source rocks may be derived from partial remelting of island arc volcanic rocks or homologous magmatic evolution.Through comparative study, the contents of Au, Ag, Cu, As, Pb and other major metal elements in this rock mass at each intrusive stage are relatively high, and its element concentration is different, and the differentiation of copper, gold and other ore-forming elements is relatively high, reflecting that the polymetallic mineralization in the area is closely related to the strong magmatic hydrothermal process of the rock mass.This rock mass has the magmatic conditions for forming porphyry copper deposits and hydrothermal gold deposits.