(all with GSWA) drafted the figures; Murray and Arthur gave their time even when under pressure for other jobs. Nell Stoyanoff (GSWA) typed most of the tables, especially the complex ones. Jean Johnston and Chris Hocking performed the unenviable task of editing the references. Brian Knyn and Eunice Cheung (Department of Industry and Resources library) managed to meet with my never-ending appetite for books and papers, often at short notice. Tim Griffin, Executive Director of GSWA, supported the writing of this book, and on behalf of GSWA funded the cost of colour figures. I thank my Chinese friends and colleagues for their hospitality and support for the numerous field trips in China and their patience with the idiosyncrasies of a Westerner: Chen Yanjing

No abstract

The Kalatongke Cu-Ni sulfide deposit in northern Xinjiang, northwest China, is located on the southern side of the regional Irtysh fault zone, which is the boundary between the early Paleozoic Altai orogenic belt to the north and the late Paleozoic Junggar terrane to the south. In the Kalatongke region there are 11 mafic intrusions which were emplaced in Lower Carboniferous strata. Economic Ni-Cu sulfide ores are found within three of these intrusions, which are well differentiated, and compositionally zoned. Four rock types are recognized which, from top to base of the three mineralized intrusions, include biotite diorite, biotite-hornblende norite, biotite-hornblende-olivine norite, and biotite hornblende-dolerite. The biotite-hornblende olivine norites and biotite-hornblende norites are the most favorable host rocks for Ni-Cu mineralization. The initial ( 87 Sr/ 86 Sr)t (t = 280 Ma) ratios of the intrusions vary from 0.70375 to 0.70504, and εNd(t) from 6.3 to 8.2, implying that the magmas originated from depleted asthenospheric mantle. However, the strong enrichment of lithophile elements such as K, Rb, Th, U, and LREE, the negative Nb and Ta anomalies, and the high δ 18 O values of whole rocks (5.4-10.6‰) suggest significant crustal contamination. These patterns are present in almost all samples from the intrusions, indicating that the contamination took place before the magma was emplaced at its present level in the crust. Crustal contamination is interpreted to have driven the magma to S-saturation and brought orthopyroxene onto the liquidus. Convection, or perhaps flow differentiation of the crystal-bearing magma during ascent, caused the dense sulfide melt with entrained olivine and orthopyroxene crystals to become concentrated in the center of the intrusions, whereas the fractionated magmas formed other, less mafic intrusions, which intrude the nearby strata.

No abstract

A high-level, small gramtic body, informally named McConnochie greisenised granite, was emplaced within Greenland Group rocks, probably above the roof region of a subjacent pluton, in the Reefton-Victoria Range area of Westland, New Zealand.The McConnochie greisenised granite is a highly evolved member of a granite series forming the western margin of the Karamea Batholith in the area of study and shows an apparent overall S-type chemistry. It was originally a granodiorite which was subjected to varying degrees of postmagmatic alteration (greisenisation) during the Cretaceous. The greisenisation affected both the original granodiorite body (endogreisen) and the surrounding country rock (exogreisen).Mineralisation occurs in both endogreisen and exogreisen rocks and consists of pyrite, marcasite, chalcopyrite, molybdenite, minor sphalerite, and native bismuth. Sn mineralisation probably occurred near the top of the greisenised granite cupola, but was later removed by erosion. This is shown by a vertical geochemical zonation in which Sn values decrease with depth in the drill core, whereas Cu and Mo are enriched in the lower and more greisenised parts of the granite body.It is possible that muscovitisation of biotite is, at least in part, responsible for the release of the ore metals during greisenisation and associated hydrothermal activity.