QMAP 1:250 000 geological map project

Background

In 1993, GNS Science gained funding from the Foundation for Research, Science and Technology to begin a new series of 1:250 000 geological maps covering New Zealand. The series has replaced the 1st edition, published in the 1950s -1960s. It incorporates the huge amount of new data that has become available since then, and embodies recent geological concepts such as plate tectonics and terrane accretion. Publication of the last of 21 geological maps occurred in 2012.

Methodology

Each of the 21 geological maps builds on existing geological data sources. Over 1700 published and unpublished geological maps were used in the compilation of the QMAP series. Many of these are viewable in the Geological Map Catalogue. The compilers of the new maps carried out substantial new fieldwork where geological data were lacking.

Construction

The QMAP project was the first national geological mapping project in the world to be designed, built and completed using Geographic Information System (GIS) software. After initially establishing technical specifications and data collection procedures, the software not only streamlined the cartographic process but also resulted in the development of a geological map database that can be updated and added to.

Seamless GIS

With the QMAP project spread over 18 years, there were inevitably new discoveries that rendered parts of adjacent maps out of date. These mismatches across the sheet boundaries have been rectified to some extent by the digital stitching of the map sheets to form a single, seamless geological map of the whole country. The seamless map exists only in digital form although parts can be printed on demand through the webmaps application or through GIS software.

Updating

The seamless GIS incorporates local updates, mostly concentrated along sheet boundaries. Further planned updates will incorporate substantial new work and reinterpretations.

Technical specifications