Study On A New Method Of Organic Hydrocarbon For Exploration Of Nonferrous And Precious Metal Deposits

Organic materials had been participated more or less in the whole mineralization process of metallic ore deposit were discovered by many geologists and geochemists at home and abroad. But at present, the organic hydrocarbon survey for metallic ore deposit prospecting belongs to the first test period yet and is a forward research field of gas geochemical prospecting. The main goals of writer to select the title of "Study on A New Method of Organic Hydrocarbon for Exploration of Nonferrous and Precious Metal Deposits" as the dissertation of doctor degree are: a. To consummate this new technique further, and to lead it up to popularization from test. b. To promote the overall understanding about the genesis, process and regularity of mineralization, the migration of gas and the forecast of prospect, c. To impel to infiltrate each other between organic geochemistry and inorganic geochemistry, solid-earth geochemistry and gas geochemistry, exploration geochemistry' and study of mineral depositAfter study for three years on the organic mass and metallization, the genesis of hydrocarbon anomalies of different metallic deposits, the test effectiveness of the method upon typical metallic deposits, the suitable fieldwork plan, the anomaly patterns and their mechanism of formation, the discernment and prospecting appraisal in unknown area, some achievements have been gotten as follows:1. After analysis of hydrocarbon to different kinds of ore, rock and inclusion, it is discovered that organic materials had been more or less participated in the mineralization process of AurAg,Sn,Pb,Zn,Cu,Sb deposits (include some mid-high temperature deuteric hydrothermal deposits). At the same time, higher content of hydrocarbon has been well preserved to present, even more than tens thousands uu I/kg. Comparatively speaking, the contents of hydrocarbon among different metallic deposits have the law of gold>tin>zinc lead and antimony>copper and molybdenum>iron and manganese. More over, it is discovered that there is a hydrocarbon halo till now around the ore body at middle-high temperature hydrothermal deposit (such as Gejiu and Dachang tin-multi-metallic deposits), or ductile shear zone deposit (such as Maanqiao gold deposit),by the hydrocarbon survey to the wall rocks of ore body in different spatial sections. These results show us fully that the hydrocarbon survey for exploration of nonferrous and precious metal deposits has a firm and reliable theoretical basis.2. Many evidences show that the organic materials exist in whole process of mineralization, from the initial concentration of mineral elements to mobilized migration (include leached out by hot brine, remobilized by remelting of magma, etc.). mineralization epoch and super imposition andreconstruction period. But organic material will changed its phase state intensely under different temperature conditions: a. In the period of initial concentration of mineral elements, the temperature is lower, and the organic material shows raw organic mass. b. In the stage of mobilization and migration of elements, and the stage of low-middle temperature hydrothermal activity, it will be transformed to hydrocarbon, organic complex and debris, c. In the period of magma formation and middle-high hydrothermal contribution, it shows hydrocarbon, carbon and asphalt, d. In the super high temperature (over 600"C) period, it shows methane, even changes to carbon,H2 and CO2. Because gas is easy to disperse away and difficult to capture, so, it is unbelievable that the organic material had been participated the mineralization process of middle-high temperature metallic deposits, and this lead organic hydrocarbon survey for prospecting of metallic deposits to be neglect for a long-term.3. The organic material is the important media and catalyst of mobilized migration of metallic elements. A huge amount gas which is produced by heat degradation from organic materials will increase the inner pressure sharply, lead the rock to produce micro-fissures, an...