中国地球化学学报(英文版)
中國地毬化學學報(英文版)
중국지구화학학보(영문판)
CHINESE JOURNAL OF GEOCHEMISTRY
2002年
2期
163-169
,共7页
geochronology%Proterozoic%sodium enriched metavolcanite%Longbohe copper deposit
The chronological data obtained by a variety of dating methods have confirmed that the sodium enriched metavolcanite series in the area of the Longbohe copper deposit at Jinping,Yunnan Province, was formed during the Proterozoic (its Pb-Pb isochron age = 1595 ± 75Ma), corresponding to the Dahongshan Group sodium enriched metavolcanites. The Sm-Nd isochron age of 1336 ± 46Ma should represent the time at which this series of volcanic rocks experienced spilitization in response to sodium metasomatism, equivalent to the time of sedimentation of the Ailaoshan Group and Yashan Group rocks. The Rb-Sr ages of the volcanic rocks and the Pb-Pb ages of copper ores have recorded the events of strong dynamic metamorphism and of strong reworking-metallogenesis of copper during the Jinningian period. Similarities in forming age, rock assemblage and isotopic characteristics between the sodium enriched metavolcanite series and the Dahongshan Group sodium enriched metavolcanite series have provided new clues to the exploration of the Dahongshan-type copper deposits in this area.