ZHANG Ke-xue¹, SU Cui-lan^1*, TANG Yong-yong², XIE Ying-ao¹, SUO Rui-qiang¹

(1. 1st General Team, Non-ferrous Metals and Nuclear Industrial Geological Exploration Bureau of Guizhou, Guiyang 551400, China;
2. State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China)

Abstract: The Nayongzhi Pb-Zn deposit, located in the southeastern wing of the Wuzhishan anticline in the central Guizhou, is the first large sized Pb-Zn deposit discovered in Guizhou Province. Based on the most updated geological information of mineral exploration in the deposit, in this paper, we have made a comprehensive analysis on its metallogenic geological conditions, including geological background, structure, stratigraphy, lithology, and rock facies. The results show that the distribution of orebodies of the Nayongzhi deposit was localized by the Wuzhishan anticline. Deep faults, subparallel to the axis of the Wuzhishan anticline, are favorable channels for the migration of ore-forming fluids. Structural and interstratigraphic fracture zones are favorable spaces for the ore deposition. The ore-hosted rocks of Lower Cambrian Qingxudong Formation have high concentrations of ore elements, indicating that they could be sources of ore materials. Dolostone and muddy dolostone of strata are important favorable ore-hosting lithologies, particularly the assemblage of muddy dolostone interlayered with nodular dolostone or fine-intermediate crystalline dolostone. Changes of depositional microfacies could create favorable environments for the ore formation, as abrupt transitional zones of depression, beach-mound, and transition microfacies are especially favored places for the ore mineralization and enrichment.

Keywords: Nayongzhi large Pb-Zn deposit; Wuzhishan anticline; metallogenic conditions; Guizhou, China

ACTA MINERALOGICA SINICA Vol. 40, No.4, 2020, page 385-393