Enrichment Mechanism Of Tungsten From Quartz Vein Type Gold Deposits In Southeast Guizhou

As one of the two major gold deposits in Guizhou province,the Southeastern Guizhou province has many quartz vein type gold deposits and altered rock-type gold deposits.The host rocks of gold deposit in Southeastern Guizhou province are mainly low greenschist facies metamorphosed rock series in Neoproterozoic formation of Xiajiang Group.The quartz vein type gold deposits are typical orogenic gold deposits.Similar to the Jiangnan orogenic belt and other orogenic gold deposits in Southern China,it is a product of Caledonian Orogeny.So far,the enrichment mechanism of high-temperature lithophile elements represented by W in gold-bearing quartz veins is unclear.Zhejiang Zhuji Chen Cai group developed from greenschist to amphibolite facies rocks,metamorphic age of Caledonian,at the same time,the metamorphic temperature and pressure have been accurately determined,for the study of Southern China migration characteristics of W during Caledonian metamorphism provide ideal research section.The quartz vein type gold deposits have complex geological structures and deposits of various ore-forming fluids in Southeastern Guizhou.It is difficult to find a general and effective method to explain the occurrence and enrichment mechanism of W in the metamorphic process.Therefore,this study the X-ray fluorescence spectrometer and inductively coupled plasma mass spectrometry(ICP-MS)was used to determine the combination of trace elements and petrography in the gold-bearing quartz veins,wall-rock and ore-hosted strata rocks samples collected in quartz vein type gold deposits of Southeastern Guizhou.The LA-ICP-MS in situ microanalysis system was used to analyze the combination of trace elements complex rock in the Zhejiang Zhuji Chen Cai.Ti containing minerals in different metamorphic facies rocks(such as rutile,titanite,ilmenite)and chlorite,biotite,hornblende,diopside,garnet minerals and W enrichment has close connection with the determination of trace elements.Combining previous research achievements of rich,the system interpretation of South China Caledonian period metamorphism in the process of migration characteristics of W,explore province quartz vein type gold deposits in the state of tungsten and the enrichment mechanism.To obtain the following knowledge:In the early metamorphic period of the Caledonian period in South China,the major enrichment stages of trace elements such as Au,As,W,and Sb.Complex tectonic movement in the gold ore area in Southeastern Guizhou,the W-bearing fluid combined with the local high-content calcareous minerals under low temperatures and pressures,forming the scheelite particles are hosted in the quartz-bearing vein.During Caledonian metamorphism,W is mainly enriched in minerals of low greenschist facies metamorphic rock series,of which W biotite is the main carrier mineral followed by ilmenite.With the increasing amount of W in the degree of metamorphism,biotite,ilmenite was released into metamorphic hydrothermal fluid migration.At the same time,rutile,sphene,titanium containing minerals and chlorite,hornblende,diopside and garnet minerals such as W will also be released into metamorphic hydrothermal fluid migration.Occurrence in containing gold quartz vein of scheelite,along with the further increase of metamorphic grade,increasing deformation and recrystallization,W elements of scheelite will by from low green schist facies metamorphic rock series of metamorphic fluid from vein body out.