Southeast Asian Island-arc Copper Metallogenic Geological Background And Geochemical Characteristics Of Minerogenic Rock

In this paper, the study area divides two porphyry copper-gold metallogenic belt,namely Sumatra-East Timor porphyry copper-gold metallogenic belt and New Guineaisland porphyry copper-gold metallogenic belt. Based on the contrast research ofore-forming geological features, typical copper deposits and the geochemicalcharacteristics, the cause of the ore-forming magmatic rocks, the temporal and spatialdistribution of copper mine resources and metallogenic potential analysis in the area willbe summarized and researched.The metallogenic geological background in the study area are mainly related to thesubduction and collision of Pacific plate, India-Australian plate and the Sunda plate.Tectonic environment is mainly the Cenozoic magmatic arc, metallogenic magmatic rocksof typical porphyry copper-gold deposits are mainly neutral rocks, porphyry coppermetallogenic era is Cenozoic. The porphyry copper deposits in the Sumatra-East Timorporphyry copper-gold metallogenic belt distribute along the Sumatra-East Timor outervolcanic arc, and are related to the Sunda-Banda arc calc-alkaline magmatism, andmetallogenic era is Cenozoic；The porphyry copper deposits in the New Guinea porphyrycopper-gold metallogenic belt located in the central orogenic belt, and are the latestproduct of subduction of the Pacific Plate. Many small intrusions, volcanic centersassociated with mineralization distribute along the island arc volcanic activity belt, andmetallogenic era is Miocene and pleistocene.The geochemistry characteristics of metallogenic magmatic rocks in Metallogenicbelt are, the medium of SiO2, neutral, low-Ti, Al-rich, Na-rich, aluminum saturation indexA/CNK>1, A/NK>1, peraluminous series rocks. Total rare earth∑REE is low-medium,and has relatively higher LREE/HREE and LaN/YbN. The differentiation of light andheavy rare earth is obvious, light rare earth is enriched, Eu anomaly is not obvious. Traceelements content is in a state of enrichment relative to the chondritic values, Rb/Sr<0.3,Sr/Ba>0.5, Zr/Hf ratio is high, the magmatic rocks experienced obvious crystallizationdifferentiation in the process of magma evolution. The causes of metallogenic magmaticrocks in the Sumatra-East Timor porphyry copper-gold metallogenic belt are mainlyoceanic crust remelting. The causes of metallogenic magmatic rocks in the New Guineaporphyry copper-gold metallogenic belt are the contamination of oceanic crust andterrigenous material.Two porphyry copper-gold metallogenic belts are at the edge of the plate movement, which is favorable to plate tectonics and magmatic activity area, and have a goodstructural background of porphyry copper deposits. There exists a series of large andsuper large porphyry copper deposits in the belts and the metallogenic era is new. For thetarget, searching for porphyry copper mine of being buried deeper or not beingdenudated in the surface should have good prospecting potential.