Abstract:

The exploration of gold deposits in southwestern Guizhou has been upgraded to the national strategic level, and it is important to clarify the gold-deposit formation mechanism. The deep substrate material has been studied using regional gravity and magnetic data in this paper. Through the delineation of the shallow and deep concealed-rock masses and the fitting calculation of the geology-gravity model anomalies, this paper has analyzed the gold mineral source combined with regional geological, geochemical and mineral data of the study area. The gold mineral source has two main supply models. One is the surface layer of sedimentary rocks providing ore-source layer previously proposed，and the other is the deep Mesozoic granite or metamorphic basement (containing basic-ultrabasic magmatite) providing ore-source layer firstly proposed in this paper.This study has determined 12 anomaly areas of the shallow concealed-rock masses,and has separated 4 large deep-magmatite blocks.The result basically reflects the general geology situation of the study area, and can provide relevant basis for gold exploration in southwestern Guizhou.

Key words: granite basement, lamprophyre, density, geological-geophysical model, material source of gold deposit, southwestern Guizhou