Physicochemical Conditions during the Formation of Dalingkou Ag-Pb-Zn Deposit,Zhejiang Province  

作　　者：魏元柏 陈武 

机构地区：[1]Department of Earth Sciences,Nanjing University,Nanjing,210008

出　　处：《Chinese Journal Of Geochemistry》1993年第3期252-260,共9页中国地球化学学报

摘　　要：On the basis of mineral paragenesis and the chemistry and homogenization temperatures of fluid inclusions,the physicochemical parameters were calculated for the formation of the Dalingkou Ag-Pb-Zu deposit in Zhejiang.From the early to the late stage of mineralization the ore-forming temperature veriation was found to be 298.5 ℃→267.0℃→217.6℃→167.3℃,with a corresponding pH change of 3.0-5.8→6.1→6.7→5.0→7.3.The pressure changed from 403.8to 128.5atm,and logfS2-9.9→-11.2→<-15;logfO2<-44→-45.6--42.6→>-44.2;and logf CO2 around -1.55.In conjunction with geological observations.the deposit is considered to be of meso-epithermal origin,i.e.,it was formed after continental volcanic-subvolcanic activity.The major factors affecting ore precipitation are the decreasing temperature and the increasing pH of ore-forming solutions.On the basis of mineral paragenesis and the chemistry and homogenization temperatures of fluid inclusions,the physicochemical parameters were calculated for the formation of the Dalingkou Ag-Pb-Zn deposit in Zhejiang.From the early to the late stage of mineralization the ore-forming temperature veriation was found to be 298.5℃→267.0℃→217.6℃→167.3℃,with a corre- sponding pH change of 3.0～5.8→6.1→6.7→5.0～7.3.The pressure changed from 403.8 to 128.5 atm,and logf_(S_2)-9.9→-11.2→<-15;logf_(o_2)<-44→-45.6～-42.6→>-44.2; and logf_(CO_2) around-1.55. In conjunction with geological observations,the deposit is considered to be of meso-epithermal origin,i.e.,it was formed after continental volcanic-subvolcanic activity.The major factors affecting ore precipitation are the decreasing temperature and the increasing pH of ore-forming solutions.

关 键 词：成矿条件 物理化学条件 浙江 银-铅-锌矿床 

分 类 号：P618.52[天文地球—矿床学] P618.4[天文地球—地质学]