Geotope is the geological component of the abiotic matrix present in an ecotope. Example geotopes might be: an exposed outcrop of rocks, an erratic boulder, a grotto or ravine, a cave, an old stone wall marking a property boundary, and so forth.
It is a loanword from German (Geotop) in the study of ecology and might be the model for many other similar words coined by analogy. As the prototype, it has enjoyed wider currency than many of the other words modelled on it, including physiotope, with which it is used synonymously. But the geotope is properly the rocks and not the whole lay of the land (which would be the physiotope).
Kratochwil, Anselm. Biodiversity in Ecosystems: Principles and Case Studies of Different Complexity Levels. Series: Tasks for Vegetation Science, XXXIV. Dordrecht, Germany: Kluwer Academic Publishers, 1999. ISBN 0-7923-5717-5.
Wiedenbein, F.W. "Geotope protection for Europe" in Geological Heritage 1993. (Erlangen, Germany: University Erlangen-Nuremberg, 1993).
Wiedenbein, F.W. "Origin and use of the term 'geotope' in German-speaking countries" in Geological and Landscape Conservation. Editors: D. O'Halloran, C. Green, M. Harley, & J. Knill. (London: Geological Society, 1994) p.117-120.