|Stone, P. 2015. The geological exploration of the sub-Antarctic island of South Georgia: a review and bibliography, 1871–2015. British Geological Survey Internal Report, OR/15/058.|
The earliest geological explorations of South Georgia in the late 19th and early 20th centuries were generally piecemeal and opportunistic, often being undertaken by expeditions with a primary focus further south. German, Swedish and British expeditions all contributed, with the development of the shore-based whaling industry from 1904 onwards providing invaluable logistic support and infrastructure. It was the commercial interests of one of the whaling companies that stimulated in 1911 the first systematic appraisal of the island’s geology in terms of its economic mineralisation potential. Although the results were disappointing, the work led to a productive cooperation with geological specialists at the University of Glasgow. Thereafter, visits by Norwegian expeditions added to the overall state of geological knowledge until such activities were curtailed by World War II between 1939 and 1945.
An important post-war development was the establishment of the Falkland Islands Dependencies Survey (FIDS) with a responsibility for scientific research in the region. Nevertheless, the next major advance in South Georgia geology arose from the series of three independent South Georgia Survey Expeditions between 1951 and 1956. Preliminary FIDS investigations into South Georgia geology followed from about 1959, lapsed during the early 1960s, but then recommenced determinedly in about 1965; at about the same time geologists from the USA began to work on the island. This renewal of interest gathered pace with the opening of a permanent base on South Georgia in 1969 by the British Antarctic Survey (BAS), the renamed successor to FIDS from 1962. The 1970s then saw the most intense phase of BAS geological activity with several geologists in the field during most austral summers. Initially this work focussed on regional survey, but increasingly the principal thrust of the investigations evolved towards specialist study of geological processes. By the end of the 1970s, the overall pattern and origin of South Georgia’s geology had been largely established as representing an active continental margin split by the opening of an island arc and backarc basin system, with the subsequent closure of the basin and deformation of its sedimentary fill of turbidite strata. Various manifestations of the latter form most of the island including the Allardyce Mountain Range. The igneous rocks form the Salvesen Mountains in the south-east of the island and parts of the south- west coast including offshore islands such as Annenkov and the Pickersgills.
In 1982, scientific work on South Georgia was once again interrupted by military conflict, this time the short-lived occupation of the island by Argentine forces. Since the re-establishment of British administration geological knowledge has been augmented by the work of an independent New Zealand expedition and additional work by BAS in pursuit of specialist interests. There has also been an expansion of regional studies integrating South Georgia into the development history of the Scotia Arc. The appreciation of that feature as a dynamic geological construct arising from large-scale lateral tectonics, and South Georgia as an itinerant continental fragment with South American associations, were clear in some early accounts of the region. Such propositions were generally discounted until ideas of continental drift matured into plate tectonics from the late-1960s onwards, when many of the early ‘pro-drift’ ideas were independently rediscovered by proponents of the new global interpretation. Geologists based in the USA were prominent in this phase of regional research.