Abstract:

One of important ore-bearing strata in southeastern Zhejiang Province is Chencai Group that is exposed in southeastern Jiangshan-Shaoxing fault zone. In this stratum, many large and medium-sized polymetallic deposits such as gold, silver, copper have been found. The source of ore-forming materials has long been a hotspot among the research of genesis of these deposits, therefore, the geochemical characteristics of metamorphic rocks in Chencai Group have also received extensive attention. This paper takes the newly discovered Zhoujiawu copper deposit in Zhuji area as the research object, then conducts a systematic analysis of trace elements and rare earth elements of metamorphic rocks and ores. The results show that the average contents of ore-forming elements and accompanying elements such as Au, Ag, Cu, Zn, S, Mo in Chencai Group are significantly higher than crustal abundance, obviously Chencai Group has a advantageous material condition for mineralization. The consistency and inheritance of REE compositions of skarn and ores suggest that in Zhoujiawu copper deposit, the elemental enrichment and even mineralization may be closely related to activation and migration of elements in metamorphic rocks of Chencai Group. In summary, this research can provide direct evidence for the understanding of the role of Chencai Group for mineralization.

Key words: Jiangshan-Shaoxing fault zone, Chencai Group, Zhoujiawu copper deposit, trace element and REE, ore-forming materials, Zhejiang