Geological features, metallogenesis and prospecting significance of the gold-copper deposits in Coromandel Peninsula, New Zealand

Coromandel volcanic zone is a world-famous epithermal gold metallogenic province, and is also the most important gold-silver ore concentration area in New Zealand. Ore deposits in the Coromandel epithermal gold ore field occur mainly in Miocene andesites and dacites of Coromandel Group, with the mineralization mainly consisting of quartz vein type and breccias type. The ore-forming fluid in the deposit shows the characteristics of meteoric water mixed with minor magmatic water, whereas the ore-forming materials indicate magmatic origin, thus belonging to the quartz±calcite±adularia±illite hypotype epithermal gold deposit. The metallogenic epoch is between 16.3Ma and 2.0Ma with the climax time at 7.0~6.0Ma. Large-scale formation of the gold ore field was related to the combined action of the Northland volcanic arc and the Colville-Lau volcanic arc, and gold mineralization reached a peak during the transformation process of the regional tectonic setting from contraction to extension. The sporadically outcropped porphyry copper mineralization associated with epithermal gold mineralization suggests great potentials of porphyry copper mineralization in this region.