PETROLOGY AND TRACE ELEMENT GEOCHEMISTRY OF THE ACID VOLCANIC ROCKS OF BAIYINCHANG ORE FIELD

The studied acid volcanic rocks make up the main core part of the Baiyinchang volcanic dome structure,and is the ore-bearing rocks of Kuroko Baiyinchang-style ore deposit as well.Based on the study on petrography,REE,major and trace element geochemistry of the acid volcanic rocks,discussions on the rocks are put on the following aspects:rock classification,rock series division, trace and REE geochemical characteristics and the tectonic setting for forming the rocks. The rocks are mainly composed of rhyolite and dacite,belonging to low-K and calc-alkaline series.Geochemical characteristics shows that the formation of the rocks typical of volcanic arc is related to the partial melting of the mantle wedge associated with plate subduction.