Jianchaling nickel deposit:Magmatic or hydrothermal origin?

TLDR: The Jianchaling nickel ore deposit is the only nickel deposit discovered in the Qinling orogenic belt, and its geological characteristics are quite unique among the Cu-Ni sulfide deposits as mentioned in this paper.

Abstract: The Jianchaling nickel ore deposit is the only nickel deposit discovered in the Qinling orogenic belt,and its geological characteristics are quite unique among the Cu-Ni sulfide deposits.A comprehensive study of geological and geochemical characteristics and metallogenic geological conditions shows that the ore deposit is strictly controlled by the ductile shear zone and the granophyre,with intense wall rock alteration seen in the wall rock near the ore bodies.Ores are characterized by veinlet structure and metasomatic texture.Mineral sequence suggests that metallic sulfides in the ores were obviously formed later than the ultrabasic rock,close to the occurrence of alteration.The alteration of albitophyre near the ore body implies that the metallic sulfides were formed also later than albitophyre.The minor elements and REE in the ores show apparent dual nature,being closely related to the medium-acid rocks besides inheritance from the ultrabasic rock.In terms of sulfur isotope,the ores are evidently rich in δ34S,whose content range and average value are quite different from those of mafic and ultramafic rocks but identical with things of medium-acid rocks in the ore district.It is thus believed that this nickel deposit was formed by the hydrothermal process and belong genetically to magmatic hydrothermal reformation type.