Skarn and Greisen Model for Tin Depositin Batubesi Area, East Belitung, Indonesia

Abstract

The research was conducted in the Batubesi area of East Belitung, Indonesia. Due to the depletion of secondary tin ore deposit, exploration development is carried out to the primary ore. The characterization of skarn and greisen models is important for the development of the primary tin ore mining business. This study aims to identify and characterize the primary tin deposits of greisen and skarn, analyze the primary tin content, and evaluate the potential of tin ore. The current research carried using topographic mapping with real-time kinematic method, grab method for sampling, XRF for grade analysis, and tin ore potential estimation based on area of influence with cut-off grades of 0.41% Sn and 0.05% Sn for skarn and greisen respectively. The results show that skarn and greisen outcrops are influenced by a fault in a west-north to east-south direction. Generally, the skarn and greisen deposits are ore, while the waste is hornfels rock. The highest tin grade value was found in skarn deposit on intrusion wall of lode where veins are controlled by crack, with grades of 0.1001-0.3% Sn (123 assay). Greisen on granite intrusion body has a lower grade of 0.0001-0.025% Sn (97 assay). The skarn on intrusion wall is considered as an ore since the average grade of 0.4567% is higher than the cut-off grade. Meanwhile, the greisen on granite intrusion body is considered as a resource because the average grade of xxxx% Sn is lower than the cut-off grade.