Studies On Structural Deformation And Mineralization Of Baiyin Mineral Field

Baiyin Mineral Field is one of the most important non-ferrous metal resource bases in China, but there are still different opinions on such key scientific issues as the formations, background, mineralization, ore-controlling conditions and structural deformation effect of the volcanic rocks. So it’s hard to provide effective help for prospecting. Based on the studied results of previous geological literatures and exploration practices, this paper presents a new opinion on petrology attributes, the structural features, mineralization and prospecting directions of Baiyin Mineral Field by modern structural deformation theories, comprehensive tectonic geology, petrology, geochemistry and new methods of prospecting mineralogy, the following are the main scientific achievements:1)The paper discovered that Baiyin Mineral Field was made of ore volcano-sedimentary rocks of the early and middle Cambrian, and the volcanic rocks were mainly basic rocks and acid rocks. Ore-bearing rock series were rhyolite and tuffeceous rocks, which had a multicyclic feature.2) The paper presented that the source of ore-forming minerals of Baiyin Mineral Field was related to epicontinental arc acid magmatic activity and experienced early-late two-stage mineralization. The early stage (578.99Ma) was metallogenic by the local accumulations of continental margin arc of acid rocks, and the late stage was the main source of ore-forming minerals for mineralization. The late stage (395.5Ma) was metallogenic mechanism of the ductile shearing deformation. In the process of the ductile shearing deformation, ore-forming elements activate and remove to favored structural location, such as dilatant zone, gathered metallogenic of brittle-ductile deformation transposition zone, the ore-body was close to ductile shearing in space and time.3) The paper set up mineralization pattern of Baiyin Mineral Field and pointed deposit alteration mineral was close to ductile shearing in space and time, and acid rock series of the early and middle Cambrian, ductile shearing zone and Sodium Mica combination was effective indicator for deposit in Baiyin Mineral Field.