Alabaster group rocks (Lower Permian) in southern skippers range north-west Otago, New Zealand

Abstract

Abstract A steeply dipping, fault-bounded sequence of Lower Permian metavolcanic and metasedimentary rocks of the Alabaster Group, with associated intrusives, has been mapped in the southern Skippers Range. The Eglinton Sub-Group, for which three new formations are proposed, consists mainly of porphyritic metabasic lavas, volcanic breccias, and metabasic (and metaandesitic) dykes of the Mantle Volcanics. Metabasalt and finely bedded, locally hornfelsed, sediments of the Hidden Flats Formation are intruded by quartz diorite and granodiorite bodies of the Mackay Intrusives. The Camp Conglomerate overlies the Mackay Intrusives in the south-western part of the present area. Much of the Eglin ton Sub-Group has been metamorphosed to prehnite-pumpellyite facies; some areas are transitional to the pumpellyite-actinolite facies. To the west, and separated from the Eglinton Sub-Group by the Wilmot Fault, is the Skippers Sub-Group, here formally upgraded from formational status. The Skippers Sub-Group comprises thre...