Legacy Geological Maps
GNS Science is custodian of a representative set of more than 9000 geological maps and field sheets that date back to the late 19th century. These historical documents record valuable information and evolving interpretation and understanding of the geology of New Zealand.
Legacy geological maps are printed or marked on paper, film and other hardcopy media. Accessibility to this archive is being improved through scanning and documenting the maps within our digital Geological Map Catalogue.
The Regional Geology Map Archive and Datafile (RGMAD) was recognised as a Nationally Significant Database in 1992 during the formation of the Crown Research Institutes. GNS Science assumed custodianship of RGMAD, and under the QMAP geological mapping project has significantly enhanced the database through the use of GIS software. In 2009, dedicated funding was directed to establishing a digital image map catalogue, in order to increase accessibility and reduce handling of the precious legacy maps.
The oldest maps within the RGMAD date back to the late 1800s, and are notable for the painstaking production of the topographic base as much as for the superimposed geological information. Many of these maps were created by teams of geologists and surveyors in the field, working with very little prior knowledge of the valley systems let alone the rocks they were to encounter.
Many of the archived geological maps are unpublished but contain information unavailable anywhere else. The unpublished maps include sheets recording field observations, preliminary compilations and advanced interpretations.
The archive includes geological maps published by GNS Science and its predecessors (the New Zealand Geological Survey, DSIR Geology & Geophysics), many of which are still in print and are available for sale.
Scales range from 1:63 360 (‘one inch to the mile’), and the metric equivalent 1:50 000, to 1:25 000 for more detailed maps, or 1:100 000 and 1:500 000 for more regional-scale maps. Some maps are associated with geological bulletins, some have explanatory text booklets, and some have text printed beside the map.
For example, there are urban geological maps of Auckland, Whangarei and Nelson amongst others, resource maps of Te Aute Limestone, Southland Lignite and Waihi, inch to mile maps of Cromwell, Takaka and Ngaruawahia, and 1:50 000 maps of the Wellington, Clarence and Milton areas.
The archive also contains geological maps of Antarctica, particularly around the Dry Valleys area within the New Zealand territory.
Example 1: Dun Mountain Subdivision fieldsheet, 1912
The early New Zealand Geological Survey bulletins included printed maps that were based on sketches on thick “Whatmans” paper. They included information collected from very difficult country, and from outcrops temporarily exposed by mining activities at the time. This water-colour example from the ultramafic rocks south of Nelson was compiled as part of the 1912 Dun Mountain Subdivision bulletin authored by James Mackintosh Bell, Edward de Courcy Clarke and Patrick Marshall.
Example 2: Aorangi Mine (Northwest Nelson, 1979)
This published 1:25 000 geological map of the Aorangi Mine area in Northwest Nelson is part of Roger Cooper’s (1979) Paleontological Bulletin on the local Ordovician geology.
Example 3: Mt Taranaki record sheet, 2005
Each QMAP sheet was initially compiled onto 1:50 000 “record” sheets that aimed to capture as much geological information as possible. This information was synthesised, culled and generalised for the final printing scale of 1:250 000, but the original record sheets have been archived into RGMAD. This example of a record sheet is from the Mt Taranaki area, and shows detailed aerial photo interpretation by Dougal Townsend in 2005.