Stories

By SGA Member Dr Bruce Mair

With input from Alexandra Tataran, Archivist and Records Officer, British Antarctic Survey

It is with regret that I report on the passing of Peter William Geoffrey (Geoff) Tanner earlier this year. He played a significant role in completing the geological mapping of South Georgia in the 1970s.

Geoff was a graduate of Sheffield University in the 1960s and moved to Imperial College London to work on his doctorate. His thesis, entitled “Structural and Metamorphic history of the Kinloch Hourn area, Inverness-shire” was submitted in 1965, and established his specialisation in structural geology. Thereafter, at the University of Leeds, he worked on the Precambrian of Connemara, and in the early 1970s on the structural setting of ore bodies in the Rwenzori of Uganda. Complex geology in complex field areas!

He joined the British Antarctic Survey (BAS) in 1973 as a Principal Scientific Officer (PSO) with the Earth Sciences Unit (Birmingham University) and in 1976 transferred to Earth Science Division (BAS Cambridge). He was responsible for coordinating the final geological mapping programmes of South Georgia, and management of BAS geologists tasked previously to do so, both in the United Kingdom and in the field.

He conducted field work from King Edward Point (Base M), and along the southwestern coastline during the 1973-74 and 1975-76 austral summers respectively. His team of geologists included Roger Clayton, David Macdonald, Bruce Mair, Rory Mortimore, Tim Pettigrew, Phil Stone and Bryan Storey. Under Geoff’s leadership, their field work and research, was published in a series of BAS Scientific Reports, BAS Bulletins and external geological publications. Geoff and his team finally completed the first comprehensive geological mapping of South Georgia, established the ages of the various stratigraphic and lithological units, and placed South Georgia in its regional context within the Scotia Arc and in relationship to the Antarctic Peninsula and the Southern Andes.

Geoff left BAS in 1979 and joined the Geology Department of Glasgow University, and subsequently became an Honorary Research Fellow in 1990. He suffered from Parkinson’s Disease in later life but nevertheless maintained his formidable reputation as an authority on the structural geology of the Scottish Highlands. In recognition, he was awarded the Clough Medal by the Edinburgh Geological Society in 2008. Geoff leaves his wife, Judith, a daughter and a son.

For a photo of Geoff see the official obituary on the Geological Society website: https://www.geolsoc.org.uk/About/History/Obituaries-2001-onwards/Obituaries-2023/Peter-William-Geoffrey-Tanner

Geoff is commemorated on the map of South Georgia by Tanner Island. The APC Gazetteer states “It is the largest and westernmost of Pickersgill Islands, rising to 145 m, [and] was named after Peter William Geoffrey Tanner (b. 1938), BAS geologist, who worked on the island, 1975-76 (APC, 1979, p. 3).

His key papers relating to South Georgia are:

• TANNER , P W G, and D C REX. 1979. Timing of events in an Early Cretaceous island arc – marginal basin system on South Georgia. 1979. Geological Magazine, 116 (3), 167-179.
• TANNER, P W G, STOREY B C, and D I M. MACDONALD. 1981. Geology of an Upper Jurassic – Lower Cretaceous island-are assemblage in Hauge Reef, the Pickersgill Islands and adjoining areas of South Georgia. BAS Bulletin, 53, 77-118.
• STOREY, B C, and TANNER, P W G. 1982. Geochemistry of a Mesozoic island-arc assemblage and ocean floor basalts from South Georgia. BAS Bulletin, 56, 7-24.
• TANNER, P W G. 1982a. Geologic Evolution of South Georgia. In: Craddock, C. (ed.) Antarctic Geoscience. The University of Wisconsin Press, Madison. 167-176.
• TANNER, P W G. 1982b. Geology of Shag Rocks, part of a continental block on the North Scotia Ridge, and possible regional correlations. BAS Bulletin, 51, 125-136.
• TANNER, P W G, and MACDONALD, D I M. 1982. Models for the deposition and simple shear deformation of a turbidite sequence in the South Georgia portion of the southern Andes back-arc basin. Journal of the Geological Society, London, 139, 739-754.
• THOMSON, M R A, TANNER, P W G, and REX, D C. 1982. Fossil and radiometric evidence for ages of deposition and metamorphism of sedimentary sequences on South Georgia. In: Craddock, C. (ed.) Antarctic Geoscience. The University of Wisconsin Press, Madison. 177-184.