The formation of orebodies controlled by thrust faults is driven by mechanical mechanisms in the Maoping lead–zinc deposit within the Sichuan-Yunnan-Guizhou Pb–Zn polymetallic metallogenic area

Abstract

In hydrothermal ore deposits, thrust faults are a common type of ore-controlling structure, yet understanding of the formation and distribution of the orebodies under their control remains elusive. The Maoping lead–zinc deposit, located in the Sichuan-Yunnan-Guizhou Pb–Zn polymetallic metallogenic province, is a representative deposit in which orebodies are controlled by interlayer faults. To address the issues of orebody extension and thickness control mechanisms for this type of deposit in the region, this paper employs the Theory and Methods of Orefield Geomechanics to study the mathematical and physical relationships underpinning the extension and true thickness of orebodies and to analyse the mechanical mechanism that determines their dip angles. Our research indicates that the smaller the angle between the thrust fault and the lower-sequence metallogenic structural planes is, the greater the extension and true thickness of the orebody. Furthermore, the orebody dip is determined by the thrust fault dip and the mechanical mechanism underlying the lower-sequence metallogenic structural planes. Based on this, at the Maoping super-large germanium-rich lead–zinc deposit in northeastern Yunnan, we determine the extension of the I-8 orebody and predict the location of a concealed orebody. This research can be effectively applied to determine the extension and true thickness of known orebodies, predict the location of concealed orebodies, and optimize the exploration engineering layout for other hydrothermal deposits controlled by thrust faults.