Scanned and georeferenced geological maps and field sheets reaching back to nineteenth-century surveys.
GNS Science preserves thousands of published and unpublished geological maps, field sheets and draft compilations. Many were produced before GIS; later scanning and georeferencing made historical geological observations accessible in a map image service.
The archive includes competing interpretations made at different times. The scanned maps form historical source evidence and should remain distinct from newer geological units, faults and boundaries interpreted in QMAP.