Most of the Blenheim urban area is built upon Late Quaternary alluvial and swamp sediment deposits. These overlie older Quaternary alluvial sediment and Pliocene gravel, sand and clay as exposed in the hills to the south.
Maps and Information
There are no geological mapping projects underway or imminent in the Blenheim area. Previously completed maps include:
2000/2018: QMAP 1:250 000 geological map
For wider and more generalised geological context of the Blenheim area, a 1:250 000 geological map was printed with an accompanying an explanatory text. Digital GIS and image versions of the map are available on DVD. The digital version has since been updated in a national GIS dataset at that nominal scale. The underlying GIS datasets have rich feature attributes.
- Begg, J.G.; Johnston, M.R. (compilers) 2000. Geology of the Wellington area(external link). Institute of Geological & Nuclear Sciences 1:250 000 geological map 10. Lower Hutt, New Zealand. Institute of Geological & Nuclear Sciences Limited. 64 p. + 1 sheet.
- Heron, D.W. (custodian) 2018. Geological Map of New Zealand 1:250 000(external link). GNS Science geological map 1 (2nd edition). Lower Hutt, New Zealand. GNS Science.
A geological map image can be downloaded(external link) or interrogated through the geological map application(external link). For GIS users, the QMAP geological feature layers can be downloaded from GNS Science’s Web Map/Feature Service(external link).
1981: Unpublished 1:25 000 geological map of Wairau Plains
A geological map at 1:25 000 of the Wairau Plains covers the Blenheim urban area (Brown 1981).
For GIS users, the layer NZL-Urban Blenheim geological units can be downloaded from GNS Science’s Web Map Service(external link).