Research On The Geological And Geochemical Characteristics And Genesis Of Xinzhuang Gold Deposit In Shanxi Province

Xinzhuang gold deposit is located in the northern part of the North China Craton intermediate belt, and in a Mesozoic tectonic-magma activation area which is embedded by the two tectonic units-the northwestern Wutai uplifts of Shanxi platform and the southwestern Yanshanian subsidence belt. The regional metallogenic background, geological characteristics of ore deposits, geochemical characteristics and ore-forming fluid features of the Xinzhuang Gold Deposit were systematically summarized. Based on these and according to for the theory of gold deposit genesis, the minerlization stages, ore-forming geological conditions, ore-controlling factors, mineralization mark, metallogenic controls and metallogeny of Xinzhuang Gold Deposit were researched. The main achievements are as follows:(1) Mineral assemblage regularity was analyzed based on the microscopic characteristics of the minerals under the microscope and field macro-geological characteristics. And mineralization stages were divided of Xinzhuang gold deposit.(2) The geological and geochemical characteristics were studied for the first time, based on the geological characteristics of ore-forming rock body, petrological characteristics and geochemical characteristics. The results are show that the rock is typical S type granite with obvious silica-rich potassium rich alkali-rich characteristics, magma originated from the remelting crustal material and the environment is orogenic environment, magma evolution experienced partial melting and fractional crystallization during the rock formation process.(3) The causes of metal sulfides were studied for the first time based on the metal sulfides chemical composition by EPMA. The results are showed that metal sulfides are hydrothermal origin.(4) The ore-forming material source and ore-forming fluid source were studied for the first time based on isotope characteristics and fluid inclusion characteristics. The results are showed that ore-forming material originated from Yanshanian magmatic activity, ore-forming fluid is mainly magmatic water and later joined the meteoric water, with medium-high temperature, medium-low salinity and medium density.(5) Ore genesis was analyzed on the basis of geological characteristics and geochemical characteristics of the ore deposi. The ore genesis of Xinzhuang Gold Deposit is Mesothermal quartz vein type, related to the Yanshanian mediosilicicacid magma intrusion activities. The metallogenic model was established for the first time of Xinzhuang gold deposit, based on summarizing ore-forming geological elements.(6) The relationship with mineralization between Stratigraphy, structure and magmatic rock were analyzed, and the ore-forming geological conditions were summarized. The ore-forming location rule and mineralization enrichment markers were summarized.