Prospecting and exploration of deeply concealed ore-bodies or deposits are the most challenge and difficult issues in ore exploration and the frontier of metallogeny. Based on comprehensive researches and prospecting practices in the Sichuan-Yunnan-Guizhou Triangle (SYGT) area in the last 20 years, particularly those of the depth and periphery exploration of known deposits, we proposed a 'Four Steps Type' ore-prospecting method for concealed hydrothermal ore deposits. First, in order to successfully apply this integrated technology system, 'four main factors' including metallogenic time, space, materials and evolution processes, and 'five links' including mineral origin, transportation, storage, change, and preserving, should be well documented. After that, it is important to determine the metallogenic geologic body of deposits, to set metallogenic structural planes, to reveal fluid characteristic symbols, to gradually establish ore-finding prediction model based on the ore-forming geological processes, metallogenic tectonic system and fluid metallogenic processes. The prospecting directions can be chosen at this stage. Secondly, it is essential to delineate the structural controls on the distribution of the deposits and ore-bodies, to define the metallotectonic system by using fine structural resolution and large-scale alteration lithofacies mapping, to delineate the natural boundaries of mineralization and screening favorable ore-prospecting zones. Thirdly, by applying fine tectono-geochemical exploration method, the mineralization center and key prospecting targets have to be delineated. Fourthly, to explore concealed or deeply buried ore-bodies in selected locations, comprehensive application of large-scale geophysical exploration techniques including high-precision tunnel gravity exploration method (TGEM), AMT, TEM and IP will be carried out to determine the occurrences and buried depth of concealed ore-bodies. A successful implication of the 'Four Steps Type' method consists of ① choosing a potential ore-prospecting direction by applying ore-finding prediction model, ② selecting favorable zones by structural resolution and alteration lithofacies mapping, ③ sorting out the most promising prospecting targets by using fine tectono-geochemical exploration method, and ④ locating the deeply concealed ore bodies by applying geophysical exploration techniques. Based on establishing the integrated ore-prospecting exploration model, deep deposits or orebodies are discovered finally through exploration engineering. The method is further exemplified by prospecting and exploration engineering in the Maoping Zn-Pb-(Ge-Ag) deposit. Important ore-prospecting breakthroughs have been made by using the 'Four Steps Type' ore-finding exploration model in the Maoping deposit, moreover, the results showed that it could shed lights on prospecting of the HZT-type deposits in the SYGT area, and it is likely that this method may be useful for ore prediction and evaluation of the overall hydrothermal-type ore deposits in sedimentary basins. © 2019, Science Press. All right reserved.
