摘要
本区铜矿床赋存于昆阳群中。昆阳群为一套前寒武浅变质岩系。
The Dongchuan copper deposit occurs in the Precambrian Kunyang Group, Yun-nan Province. Its principal features of sulphide sulfur isotope composition may beoutlined as follows: 1. δS^(34) values range from -3.76‰ to +14‰. Average δS^(34) of the main orebody is positive with the exception of copper bearing magnetite beds for which amean δS^(34) of about -3.46‰ is noticed. 2. δS^(34) values tend to increase upward stratigraphically and appear to be slightlyhigher in Losue dolomites (i.e., reef facies) than in the transitional beds. 3. Partitioning of S^(32) and S^(34) between coexisting sulfide minerals is commonlyrecognizable. Chalcocite is generally richer in S^(34) relative to bornite. 4. δS^(34) of fissure ores is higher than that of banded ores. In accordance with the above data it is suggested that the sulfide sulfur of thecoppor deposit comes mainly from marine sulfate through reduction by biologicalagents. Volcanic sulfur seems to be of negligible significance.
出处
《地球化学》
CAS
1978年第3期242-246,共5页
Geochimica
