The New Digital Geological Map of Europe and Standardisation: Consistency as the Last Refuge of the Unimaginative?!

Abstract

A geological map is without doubt the visual language of geologists (Rudwikc1976). Given a geological map of anywhere in the world, a geologist will be able to share a basic understanding of the disposition of the rocks that the map author depicted. Further, with a little time to interpret the maps and their legends, most geologists could make sense of two maps of adjacent countries, even though the linework and classification systems may not always be the same. Unfortunately computers, Geographical Information Systems (GIS) and digital databases do not possess such powers of interpretation and deduction. They do not comprehend that polygon X on one map is probably the approximate equivalent of polygon Y on the other. Although systems using fuzzy logic are currently being investigated, most GIS and databases require data to be logically structured and relationships between features and attributes to be explicit and not merely tacit. Using the example of the 1:5 Million International Geological Map of Europe and Adjacent Areas (IGME 5000) project, this paper will explore some of the reasons for the inconsistency in geological maps and classification systems, illustrate why this poses serious problems for those who wish to construct and use geological GIS across regions and countries and introduces a few evolving initiatives on digital geological standards.