Abstract:

 The Liaotun gold deposit, located in northwestern Guangxi, is the only gold deposit spatially closely related to quartz porphyry. The metallogenic significance study for quartz porphyry will be helpful in the recognition of the genesis of Carlin type gold deposit in this district, and will provide more basis on further prospecting. Based on the geological characteristics of the deposit and geochemical characteristics of quartz porphyry, the paper regards that the quartz porphyry rocks belong to acid rocks and calc-alkaline series, which have a feature of rich K and full Al，and belong to the remelting magmatite. The ore-forming materials may mainly derive from clastic rocks of Middle Triassic series, but we can not exclude the probability that the ore-forming materials derive from quartz porphyry. The geological characteristics of the field and the analysis data of geochemical indicate that  there are at least two stages of mineralization in the ore field, and that the mineralization occurs before or after the diagenesis of quartz porphyry. Fracture zone were formed by structural shearing. The later ore thermal fluid transport, unload, and mineralize along the fracture zone; the alteration and the metallization occurs in quartz porphyry around the fracture zone, forming the mineralized quartz porphyry. Both in our country and abroad, there is growing evidence that the formation of Carlin type gold deposits are associated with the activities of the magma. In this district, the mineralization is probably related to the invasion of quartz porphyry in Yan-shanian; and it provides the ore-forming material, fluid, or heat source. These questions need further study and discussion.

Key words: metallogenic significance, geochemical characteristic, quart porphyry, Liaotun gold deposit, Bama, Guangxi