Geological maps in national atlases

Summary

This article reviews the group of geological maps in national atlases, comparing the form and content of geological-stratigraphic, tectonic, mineral-deposits, lithological-petrographic, and Quaternary-deposits maps, and offering recommendations for greater uniformity. The author notes significant variations among published atlases in the number and headings of geological maps, base-map compilation principles, representation methods, and completeness, attributing these to both natural and socio-economic conditions and subjective compilation approaches. To ensure comparability and integrated regional study, the article emphasizes the need for consistency within the geological map group and with other physical maps regarding mathematical and geographical bases, content complementarity, classification detail, and generalization degree. It discusses how stratigraphic detail varies with map scale and geological knowledge, and addresses issues of legend logic, color standardization, and international indexing. The article recommends that mineral-deposits maps be compiled at the same scale as geological maps to facilitate studying deposit distribution and structural associations. It also suggests including supplementary maps tailored to national characteristics, such as hydrogeological maps for arid countries and structural maps for platform regions, while noting the need for further work on Quaternary deposit classification and tectonic map legends.