Applying Three-Dimensional Modeling Based on Trench Surveys to Chromitite Orebodies in the BophiVum Area, Northwestern Myanmar

The BophiVum massif in northwestern Myanmar mainly consists of peridotite, mafic intrusive, and mafic volcanic rocks, oceanic sediments, and chromitites. Small chromitite open pits are randomly distributed in the eastern lowland of the massif. In this study, we interpret the origin of the chromitite and suggest exploration guidelines for hidden orebodies, by understanding their random distribution in three-dimensional (3D) space. This is accomplished by inputting the geological survey data into 3D modeling software. Trench and geological surveys were conducted on the selected ridge (detailed study area) that contains chromitite of a certain thickness and predictable extent to analyze the characteristics of orebody distribution. The general characteristics of the chromitite deposits investigated from the field are: (1) they occur as lenticular pods hosted by dunites, (2) they are located close to the harzburgite-dunite boundary, (3) they are not present in all dunites, and (4) the dominant trend of the dunites and chromitites is WNW or NW-trending. These individual field data were integrated by importing them into 3D modeling software and the resulting model showed the characteristics of chromitite distribution in 3D. The results are: (1) composed of six discontinuous chromitite pods, (2) occurring in a WNW or NW-trending arrangement, (3) located at the WNW or NW-trending lenticular dunite boundary, and (4) maximum depth being 30 m from surface. This study provides useful data for exploration of hidden orebodies in the study area and suggests a new method for integrating field data in 3D space.