THE KROK KLEIVA ESCARPMENT: A CRITICAL SECTION IN THE APPLICATION OF PALEOZOIC SYSTEMS TO 19TH CENTURY NORWEGIAN GEOLOGY

Roderick Impey Murchison (1792-1871), an eminent British geologist whose reputation was in large part based on geologic field work, used throughout his career a research method that enabled him to rapidly survey large areas, apply recent advances in the science of geology to those large areas, and present his results in a timely and widespread manner. During a two week campaign in 1844 Murchison examined the geology of southern Norway in company with other expert geologists including Leopold von Buch of Berlin, George Forchhammer of the University of Copenhagen, and Baltazer Keilhau of the University of Christiania (now Oslo). The latter had prepared a geognostic geologic map for southern Norway which Murchison used during his visit and revised in later publications, notably The Geology of Russia (London: John Murray, 1845). One section in particular, from the floor of the Steinsfjorden valley up onto the Krok-kleiva escarpment, was crucial to Murchison's revision of the local geology. Whereas Keilhau's map portrayed the lithologies and their contacts in an accurate fashion, Murchison applied the new Silurian and Devonian system terminology to those rocks and consequently achieved a major advance in Norwegian geology. Some of the results of Murchison's Norway work included: (1) an extension of Paleozoic rock system terminology into Scandinavia; (2) a new name, Azoic, for the older, non-fossiliferous basement rocks; and (3) recognition of the effects of younger igneous intrusions on country rock.