The Study Of Tectonic-Alteration-Facies Zoneing And Its Prospecting Forecast In Linglong Gold Ore-field

The Linglong ore-field which locates in Zhaoyuan City is the most important gold base in China, Shandong Province. The Linglong granite can be found in most areas and the Quaternary also can be found in some areas in the ore-field. The ore-control structure can be divided into two types which are transtension fracture and transpression fracture. The former controls quartz vein ore, and the latter controls altered rock ore. The purpose of this paper is to research the geological distribution, metallogenetic rules, age of alteration, and geochemical composition in two types of zoning of tectonic-alteration-facies, and then make prospecting forecast in Linglong gold field.The study suggests that the tectonic-alteration-facies zoning can be divided into two types which are the quartz vein one and the altered rock one. The tectonic-alteration-facies zoning of quartz vein type includes the phyllic alteration zone, strongly potassic alteration granite zone, feebly potassic alteration granite zone and granite zone. The tectonic-alteration-facies zoning of altered rock type also includes the phyllic alteration zone, strongly potassic alteration granite zone, feebly potassic alteration granite zone and granite zone. The main differences between two types are the ore type, alteration scale and circumstances that formed. The alteration scale of tectonic-alteration-facies zoning which controlled the quartz vein ore is small, and it was formed in the circumstances that the ore-forming fluids was in middle-low temperature and oxidation, the chemical composition was moved into, and the LREE was enriched. The alteration scale of tectonic-alteration-facies zoneing which controlled altered rock ore is rare large, and it was formed in the circumstances that the ore-forming fluids was in middle-high temperature and deoxidization, the trace element composition was moved into, and the HREE was enriched. The alteration age of K-feldspar in Linglong fracture zone is 69.47±0.9～110.3±1.0Ma. The alteration age distribute shows that the faults moved during the metallization phase which the motion spurs ore-forming fluids superimposed mineralizing process and the postmineralization which the faults broke up the continuity of ore veins that formed in Xishan and Dongshan field. The alteration age of K-feldspar in Jiuqu is 90.35±0.88～99.49±1.01Ma, focus on 90～100Ma. The alteration age distribute shows that the three alteration zones were made from the co-hydrothermal fluids which stayed in middle-low temperature.The traditional prospecting method always belongs to exploring ore by ore in a small rage. But the mapping method of tectonic-alteration-facies zoning provides us a suitable and big range prospect mark which can be used to explore buried ore. With the mapping method of tectonic-alteration-facies zoneing, we forecast much potential resource having been preservation in the deep area of Linglong field. The NE concentrated mineralization zone which the gold ore maybe found in the depth of 1500m is the first important place, the NNE concentrated mineralization zone which the gold ore maybe found in the depth of 1200m is the second important place, and the NEE is the third important place.