Quantitative analysis of intrusive body morphology and its relationship with skarn mineralization—A case study of Fenghuangshan copper deposit, Tongling, Anhui, China
(Key Laboratory of Metallogenic Prediction of Nonferrous Metals of Ministry of Education, School of Geosciences and Info-Physics, Central South University, Changsha 410083, China)
Abstract: The shapes of intrusive body and contact zone might influence the formation and distribution of orebodies in skarn deposit. By taking Xinwuli intrusive body in Fenghuangshan copper deposit, Tongling, Anhui, China, as the research object, a new method was used to obtain the quantitative relationship between intrusion morphology and skarn mineralization. The first step of the method was to extract morphological characteristic parameters based on mathematical morphology and Euclidean distance transformation; then the quantitative relationship between the parameters and orebodies was analyzed; finally correlational analyses between the parameters and mineralization indices were conducted. The results show that morphological characteristic parameters can effectively indicate the location of concealed ore bodies in skarn deposit, with the following parts as advantageous positions of skarn mineralization: (1) the parts away from the 1st trend surface in the range from -25 to 50 m; (2) the convex parts about 200 m away from the 2nd trend surface, around which the tangent plane of the intrusive body is approximately consistent with the trend surface; (3) the contact zones with angle between intrusive body original contact surface and trend contact surface ranging from 35° to 70°; (4) the parts with angle between intrusive body original contact surface and regional extruding far crustal stress ranging from 50° to 60°. These knowledge can be applied to more skarn deposits for future mineral exploration.
Key words: intrusive body morphological analysis; contact zone; mathematical morphology; skarn mineralization; Fenghuangshan copper deposit