The Indicative Significance Of Mineralization From Complex Plagioclase Crystal Groups

The Deshun rock mass and its surrounding areas in Lalingzaohuo area are rich in mineralization.For example,there are a large number of magnetite veins and clumping in the rock mass,and sulfide droplets dominated by pyrite appear,and the surrounding areas are characterized by jarosite belt and ferritization.However,the sulfide is the product of the reducing environment,and the oxide is the product of the oxidizing environment.No magma has been found in the world that can melt out the oxide and sulfide droplets at the same time.To find out whether rock mass of oxide and sulfide bead drip is the result of melt-fluid mixing or the result of magmatic liquation,and what is the formation process of Deshun rock mass,this article starts with Deshun rock mass,analyzes the genesis and mineralization of Deshun rock mass.Laboratory studies include petrographic observation of samples,electron probe testing of major minerals and whole-rock microelement analysis of fresh samples.Based on rock mass mineralogy study we found that the granularity,structure and composition profile of plagioclase in rock mass are very different and the plagioclase at least can be divided into four crystal group,formation of the magma rock mass has experienced four different depth of magma house system.According to the electron probe data calculation of black mica,plagioclase and hornblende,the temperature of mineral crystallization range between 740-840 ?,pressure range between 0.29-2.93 Kbar,corresponding mineral crystallization depth is between 1.10 to 11.07 km.Different temperature and pressure ranges suggest that minerals such as amphibole formed in different magma Chambers or underwent melt-fluid migration during the formation process.The electron probe results of pyrite show that the pyrite is magmatic hydrothermal.The results of whole-rock geochemical analysis of the rock samples show that the magma forming the rock mass came from the crust and may have undergone magmatic mixing during the formation process.The negative europium anomaly in the sample may be related to the crystallization separation of plagioclase before or during the magmatic rise.Comprehensive geochemical analysis results,the main mineral of the microscopic observation and electron microprobe analysis,think that Deshun rock magma derived from crust,in the process of formation,the rise of the melt-fluid passes through the different depth of 4 magma house system,melt-fluid carries the crystals formed in the lower chamber into the upper chamber and mixes them with the mel ts in the upper chamber.The continuous repetition of this process eventually forms the quartz diorite magma.In the rising process of melt and fluid,on the one hand,it opens a channel for the rising of ore-bearing fluid;on the other hand,the formation of rock blocks the space for the upward escape of ore-bearing fluid,and forms a good sealing circle together with the surrounding thick skarn.The mixing of various melts and fluids also leads to the simultaneous appearance of oxide and sulfide droplets in the Deshun rock mass,which improves the metallogenic potential of the Deshun rock mass.