Typomorphic characteristics of pyrites in the Pangjiahe gold deposit, Shaanxi Province and indication for deep ore prospecting

This paper is the result of mineral exploration engineering.

Objective  Pyrite is the most common metal mineral of the Pangjiahe gold deposit, and it is also the most important gold-bearing mineral. Its typomorphic characteristics contain abundant geological information.

Methods  This paper conducts systematic analysis and research by selecting the morphological typomorphic characteristic, pyroelectric typomorphic characteristics and compositional typomorphic characteristic of pyrite, which is newly discovered in IV- 2 ore body in the eastern part of the deposit.

Results  It is found that crystal morphology of pyrite is mainly cubic and pentagonal dodecahedron, characterized by high arsenic, iron deficiency and sulfur. The average value of Fe/(S+As) is 0.860, and the ratio of Co/Ni is mainly concentrated between 1 and 10.

Conclusions  The calculation shows that the deposit is formed in a shallow depth, medium-low temperature environment, and the ore-forming fluid has obvious metamorphic properties. The vertical variation of pyroelectricity and morphology of pyrite indicates that there is still potential for deep ore prospecting, and preliminary calculations indicate that there is still an extension of 186 m downward ore at elevation of 861 m.