The Edinburgh Geologist
Issue no 32


How plagiarism, imagination, frustration and luck have contributed to offshore geological nomenclature 

by Ken Hitchen

In the first of a series of articles, Ken Hitchen of B.G.S. takes a light-hearted look at the naming of offshore topographic and geological features.


When mapping onshore, geologists have often resorted to local place names in order to identify structural features, rock units and rock types. Examples are commonplace: the Ballantrae Complex, the Portree Shales, appinite and so on. Offshore, however, where location names are restricted to a few bathymetric shoals or deeps, the naming of new features is more problematical. Fishermen have been responsible for naming many offshore bathymetric features but exploration geologists in the hydrocarbon industry have found it necessary to coin many new names for features which are not apparent at the sea bed and indeed, in the nether regions of the North Atlantic Ocean, have even had to name sea-bed features as well. 

It is easy to understand that the Wyville-Thomson Ridge and George Bligh Bank are named after famous explorers but who was the Rosemary of Rosemary Bank? And why was Lousy Bank so called? Perhaps the fishing was always poor here or the weather consistently rough. Or was someone suffering from sea-sickness, a hangover or just having a bad hair day? The adjacent bank to the NE of Lousy Bank is Bill Bailey's Bank, reputedly named after the song of the late 1950s. But this begs the question: who was Bill Bailey? 

The first references to Rockall Island appear as Rocol, Rokol, Rookol or Rochol on early seventeenth century maps although the actual location of the island on the early maps is some distance away from its known position today. Certain ferromagnesian-rich patches of the main Rockall granite were originally christened 'rockallite' but this has subsequently been recognised as being no more than a feldspar-deficient variety of the main granite and the name rockallite has fallen into disuse. However, many of the sea-bed sediments west of Scotland are sands comprised largely of the shells of dead foraminifera and of these, Nummulites rockallensis, one of the largest forams of its type, is a primary constituent. So in geological circles the name Rockall lives on as a major igneous centre and a tiny microfossil. In shipping circles it is known for causing the demise of several vessels as well as being mistaken (under peculiar lighting conditions) for the sails of a yacht and a submarine conning tower. Apparently it has also been used by the navy for target practice (still bearing the scars today) and as the temporary home for such inhabitants as Tom McClean, a former paratrooper who, in 1985, camped on the rock and painted a 6' by 4' Union Jack to "emphasise its Britishness". In 1997 activists from Greenpeace placed a survival capsule on the rock, lived there for several weeks and declared the existence of the new state of "Waveland" for which they issued 'passports'. This action was a protest against further oil exploration on the Atlantic margin. Three kilometres ESE of Rockall is Helen's Reef from which an unusual, but as yet unconfirmed, Late Cretaceous age has been obtained for the microgabbro recovered from it. The reef takes its name from the Dundee brigantine Helen which struck it on 19 April 1824 with the subsequent loss of 16 passengers. The crew of 12 escaped in a long-boat and was rescued. Whatever happened to women and children first? 

Many shallow bathymetric features on the south-western edge of Rockall Plateau have been christened with place names borrowed from J.R.L.Tolkien's famous books The Hobbit and Lord of the Rings. Hence we have the Rohan, Gondor and Eriador Seamounts and the Lorien, Fangorn and Edoras Banks. But there is only one feature which is named after a person from these novels. Gandalf's Spur takes the name of the wizard who helped Bilbo Baggins (the hobbit) and the twelve dwarves in their many adventures as they searched for the mighty treasure guarded by the fiery dragon in a cave under the mountain. 

More recently the BGS Geophysical Image Atlases have christened several igneous complexes in the same general area utilising names taken from a series of four books by Antony Swithin, a former geology lecturer at Leicester University. As a boy, Swithin was fascinated by the remote Rockall Island which, in his imagination, became a continent of magical places and beings. His novels, about the mythical continent (!) of Rockall, and written in a similar vein as Lord of the Rings, have provided names for the Lyonesse, Owlsgard, Sandarro and Sandastre igneous centres. Swithin has been honoured (?) by having a centre named after him. It is one of the larger ones in the area and may be at least partially responsible for the prolongation of the NW part of Rockall Bank. 

As far as buried features such as basement ridges, sedimentary basins and volcanic centres are concerned borrowing names from onshore has been a very popular solution. Hence around Scotland's coast we have understandable, if rather unimaginative names, for such structurally high features as the East and West Shetland Platforms, the Caithness Ridge and the Peterhead Ridge etc. Many geological basins have been similarly christened: the East and West Shetland Basins, Unst Basin, Fair Isle basin etc. Occasionally existing bathymetric, fishing or Admiralty terms have been applied to offshore structures. Hence the North Minch Basin, a large half-graben filled with Torridonian, Permo-Triassic and Liassic sediments and with its western margin defined by the Minch Fault, takes its name from The Minch seaway with which it is approximately coincident. The Witch Ground Graben, Devil's Hole Horst and Halibut Horst are names taken from existing fishing charts, the latter after Halibut Bank. 

Using existing onshore or island names has occasionally resulted in confusion. It may be wholly applicable for the Flannan Ridge to be so called after the Flannan Islands as these are the only subaerial expression of the NE-SW trending, Lewisian basement feature. However the island of Rona, the subaerial expression of a small fault-bounded basement block and after which the 100km-long basement Rona Ridge is named, is not actually situated on the ridge at all but is quite some distance from it. This was only realised after further subsurface offshore mapping by which time the name of the ridge had become too well established to change. On a similar note, the West Flannan Basin is west of the Flannan Islands, but why is the West Lewis Basin actually north of Lewis? 

There are far more Tertiary central igneous complexes offshore than the few in the Inner Hebrides. A variety of methods has been used to name them. St Kilda and Rockall utilise the islands of the same name. Geikie and Darwin are taken from the BGS map sheets of those names (which in turn were called after famous scientists). Erland (north of Shetland), as originally spelt by geologists in Britoil, was renamed Erlend 'after the Norse king, rather than the anglicized version previously proposed' in the subsequent definitive paper on the complex. The result, of course, is confusion and both spellings are now seen on maps. A granite, geographically associated with Erlend, but Caledonian (c.400Ma) in age rather than Tertiary, has been called the Rendle granite. Crossword fanatics might see the connection. Should it have been the Randle granite? The Anton Dohrn seamount was named after the research ship of that name which, in turn, had been named after a German marine biologist of the last century. Further afield, the Mammal Complex, 190km WNW of Rockall Island in the Hatton-Rockall Basin, was so-called because on certain seismic cross-sections the profile of the feature appears 'similar to that of the female breast'. One wonders if the geologists in question had seen a mermaid or merely spent too long at sea. 

Finally, if naming features appears to be a random process, can it ever be worse than using the pin method? Hold a pin over a map (in this example, one of onshore Shetland), shut one's eyes, stick pin in map, name feature after hamlet nearest to pin-prick. Eureka! This is how the Sandwick Basin, a small half-graben NW of Unst containing mainly presumed ?Devonian rocks, got its name. Is this true? I should know. I held the pin. 

Author's note: After writing this article, and purely for the sake of nostalgia, I unearthed a map of Shetland to locate the hamlet after which the Sandwick Basin was named - only to find that there were several locations called Sandwick or Sand Wick, something that I hadn't realised at the time. In fact the gazetteer lists a total of fifteen. It is somewhat ironic therefore that the actual hamlet after which the basin was named cannot now be unquestionably identified unless I can find the original map with the original pin-prick! 


Ken Hitchen is the geologist in charge of the B.G.S. Rockall Project and appeared in print in the last issue of THE EDINBURGH GEOLOGIST with a piece on a missing volcano. He agreed to write this article after being asked just how the existing volcanic centres were named.

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