The Copper Polymetallic Deposits Tectonic Ore-controlling Featuresand Metallogenic Regularity In Saishitang Area

Situated on the joint of East Kunlun and West Qinling, the Saishitang area is located in the Xinghai county, the southeast of Ela Mountain, Qinghai province. It belongs to Ela Mountain polymetallic ore belt, the Saishitang-Rilonggou sub ore belt. As it’s located in the alpine region, coupled with complex geological structure and other factors, it is restricted that the understanding for the genetic types and ore-controlling facors of this area. Currently the prospecting work has met the “bottleneck”. Therefore, the Saishitang and Tongyugou copper polymetallic deposit are choosed for the research of metallogenic law and genetic types of mineral deposits, providing theoretical basis for the next step prospecting direction. On the basis of predecessors’ research, through field survey and indoor synthetic analysis, based on the theories of mgmatic metallogeny, from the analysis of structural characteristics, magma nature and mineralization period, the author study metallogenic regularity of copper polymetallic deposit in the Saishitang area. The following results and understanding are achieved.1. The researched region is located in the joint of the East Kunlun and West Qinling and belongs to part of Qinling-Qilianshan-Kunlun orogenic system, composed of the East Kunlun and West Qinling tectonic units. With affected by the northwest side of the Ela Mountain tectonic zone, the stratum widely distributed volcanic rock, originated from the Permian series and late Triassic series strata. Volcano-sedimentary formation caught in the marine sedimentary strata is the major ore-bearing strata. The ore body is mainly from intermission of volcanic rhythm, the andesite and volcanic tuff. The intrusive rock in the study area is divided into four phases and the quartz diorite rock mass of the second phase is closely related to mineralization. The metallogenic background is intraplaterift tectonic environment.2. There are two mineralization in the study area. The early volcanic rock experienced mineralization and the ore body is mainly from intermission of volcanic rhythm. The earlyvolcanic rock mineralization age is the Late Triassic. Minerals in the early mineralization are rich in Cu, Pb, Zn and Sn elements. Late intermediate-acidquartz diorite rock mass is related tomineralization. The late mineralization age is the Late Triassic.Minerals in the late mineralization are rich in Cu, Pb, Zn, Sn and Mo elements. The genetic type of the deposit is that eraly volcanic sedimentary copperdepositsuperimposed on late skarn-porphyry copper deposit.3. As the ore body is mainly from late of volcanic rhythm in study area, searching sequentially along the dip of main ore-bearing horizons is one of the prospectingbreakthrough. Late mineralization was related to quartz diorite and granodiorite intrusive body. Intrusive mass can bethe key point for exploration. The circular structure area in the 1:500000 remote sensing imagery is the emphases of exploration. The circular structure could indicats that there may exist volcanic edifice and the volcanic edificeis closely related to mineralization.