Geology of the pre-Cenozoic basement of the Taranaki-Cook Strait-Westland area, New Zealand, based on recent drillhole data

Abstract

Nine wells drilled in the Taranaki-Cook Strait-Westland area intersected preCenozoic basement or basement-derived material. Petrological examination of cores and cuttings from these wells suggests that the Rotoroa Igneous Complex, the Separation Point Batholith, the NW Nelson Paleozoic metamorphic rocks, and possibly the Karamea Batholith extend from the South Island in a N-NNE direction beneath the Cenozoic cover. The trend of these rocks parallels the western margin of the New Zealand Geosyncline, supporting the suggestion that they constituted a foreland region during the development of the Geosyncline in the North Island, and were an important source of clastic material within it.

Basement geology of Taranaki and Wanganui Basins, New Zealand

“…As expected from the studies of Cope & Reed (1967) and Wodzicki (1974), samples from wells in the eastern half of Fig. 2 (east of long.…”

“…The igneous rocks in Ariki-1 are not dissimilar to those in nearby Tangaroa-1, for which core was available and which we studied in greater detail (see below). We concur with Wodzicki's (1974) We can add little to Wodzicki's (1974) detailed description of the indurated ignimbrite-rich brecciaconglomerate in Tasman-1 (Fig. 2).…”

“…Cope & Reed (1967) examined material from 10 onshore North Island oil exploration wells and proposed correlations of the indurated sandstone and schist in the wells with various facies of the New Zealand geosyncline (Eastern Province). Wodzicki (1974) examined basement material from four offshore oil exploration wells in the area of Fig. 2 and showed that various Western Province igneous and metamorphic rocks were represented.…”

Marine seismic measurements in the New Zealand region

“…At least 1·5 s of sediments occur on either side of the ridge (profile E44). Drillhole Cook 1, located over the ridge between profiles E16 and E26, penetrated about 2·7 km of late and post Cretaceous sediments (Wodzicki 1974). This, and adjacent profiler data, suggest that the ridge plunges to the north.…”

A cretaceous ‐ early tertiary Macrotidal estuarine‐fluvial succession: Puponga coal measures in Whanganui inlet, onshore Pakawau sub‐basin, Northwest Nelson, New Zealand

“…Late Cretaceous-Cenozoic sediments deposited in the Pakawau Sub-basin unconformably overlie a basement of metamorphosed Paleozoic sedimentary and volcanic rocks and schists, which was intruded by Early Cretaceous granites (Bishop 1971;Wodzicki 1974). Upper Cretaceous and early Tertiary sediments, the Pakawau Group, comprise conglomerate, sandstone, siltstone, mudstone, and thin seams of coal (generally <1 m thick).…”