Geology, geochemistry, and mineralisation of the Endeavour Inlet antimony-gold prospect Marlborough Sounds, New Zealand

Abstract

Geological, geochemical, and ore microscopy studies were undertaken on the Endeavour Inlet antimony-gold prospect, Marlborough Sounds, New Zealand. The occurrence lies along the southern tracts of a NNW-trending shear zone. It is characterised by a series of quartz veins of variable strike length and thickness. Stibnite occurs as sporadic lenticular bodies within the quartz vein system. Other ore minerals are arsenopyrite, pyrite, marcasite, and trace amounts of gold. The deep topographic relief of the area has made it possible to conduct the present investigation on key outcrops over a vertical range of approximately 400 m, Mineral zoning is well developed: stibnite is the predominant ore mineral vertically above arsenopyrite, pyrite, and gold. It is concluded that the mineralisation derives from a hydrothermal system motivated by connate waters and developed during the same metamorphic event that formed rocks of chlorite Subzone II rank (Marlborough Schists). The quartzo-feldspathic and mafic metavolcanic components of the metamorphic rocks are considered to be the likely source of metals. © 1979 Taylor and Francis Group, LLC.