Mineral prospectivity mapping for Porphyry-type and hydrothermal vein-type copper deposits using fuzzy analytical hierarchy process and geographic information system

摘要

Mineral prospectivity mapping (MPM) is used to delineate target areas that most likely contain mineral deposits of a particular type. With MPM, it is difficult to properly present the geological, geophysical, geochemical and remote sensing information representing the metallogenic favorability, due to the complexity and uncertainty of ore-forming background, cause and mechanism. Fuzzy analytical hierarchy process (AHP) has been proposed to reflect various fuzzy concepts in MPM objectively. It is an extension of conventional AHP and employs fuzzy set theory to handle uncertainty. In this study, fuzzy AHP and geographic information system (GIS) were applied for mineral prospectivity mapping. Results confirm that fuzzy AHP is an effective knowledge-driven MPM method. In the MPM process, GIS serves as an auxiliary tool of fuzzy AHP, achieving the processing and integration of basic data, spatial analysis, and result presentation. The classes of 15 Alternatives layers are assigned with weights according to the studentized contrast (S(C)) in weights-of-evidence method. That is why the fuzzy AHP-based MPM could make a better prediction in this study.