QM9 Nelson
The Nelson 1:250,000 geological map covers 11,500 square km of the greater Nelson alnd area and part of Marlborough in the northwest of the South Island, New Zealand.The area comprises rugged, recently deglaciated Tasman Mountains in the west and the lower Richmond Range and other ranges in the east separated by the down-faulted low-lying Moutere Depression. In the southeast, the Wairau valley separates the Richmond Range from the southern Marlborough mountain ranges. The offshore part of the Nelson QMAP area is characterised by relatively shallow water depths. The Paleozoic Buller and Takaka terranes, separated by the Anatoki Fault, and plutonic intrusive rocks form the geological basement in the western half of the map area. The eastern basement comprises the Median Tectonic Zone and the Brook Street, Murihiku, Dun Mountain-Maitai, Caples, and Torlesse terranes.
A regional unconformity separates Late Cretaceous and younger rocks from the indurated basement. Numerous outwash gravels and marine incursions occurred between and during the Pleistocene glaciations followed by extensive postglacial alluvial and marine deposition in the Holocene. Resources currently being extracted include aggregate, clay, limestone, dolomite, and building stone, plus bituminous coal and metallic minerals.
Natural hazards include slope instability, seismotectonic hazards, erosion, flooding, and tsunami.