The Mechanism of Structural Control of Ore Formation and Geochemical Characteristics in the Massive Sulfide Deposits of the Wushan Copper Ore Field,Jiangxi

Abstract The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushan copper orefield may be generalized as the control of ore deposition by optimum surface in an ore- forming structural trap. The mechanism has three major features: (1) timing of mineralization; (2) positioning of host formation; and (3) dependence of ore-controlling structure on properties of rocks. The “optimum surface” is a divisional structural plane which marks obvious difference in physical, chemical and mechanical properties and is favorable for mineralization. It is also a unity of structures, lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the major characteristic elements in the ore- controlling fault belt: elements with a small radius (Si, Fe, Mg and Al) moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remote from the center.