The Edinburgh Geologist Magazine of the Edinburgh Geological Society Issue No 63 Spring 2018 The Edinburgh Geologist Issue 63 Spring 2018 Cover Illustration An ultramafic pyroxenite from the Ballantrae Complex, SW Scotland, a relic of oceanic mantle seen here in thin section with crossed polarisers; the field of view measures about 2 mm by 3 mm. For more on the plate tectonic setting of the Ballantrae Complex see the article by Doug Fettes on page 14. BGS images are reproduced by permission of the British Geological Survey ©NERC. Published February 2018 by The Edinburgh Geological Society (Charity registered in Scotland number SC008011) www.edinburghgeolsoc.org Editors Phil Stone Bob McIntosh [email protected] [email protected] British Geological Survey The Lyell Centre, Research Avenue South, Edinburgh EH14 4AP ISSN 0265-7244 The Edinburgh Geological Society was founded in 1834 with the twin aims of stimulating public interest in geology and advancing geological knowledge. We organise a programme of lectures and excursions and also publish leaflets and excursion guides. For more information about the Society and membership, please visit www.edinburghgeolsoc.org. EDITORIAL Ice, plates and tombstones An editorial ramble by Phil Stone Those of you who have been paying To quote: “In December 1967, Dan attention to Scottish Journal of McKenzie and Bob Parker published a Geology will know that I have been paper in Nature — ‘The North Pacific: taking an interest in the activities of an example of tectonics on a sphere’. the 1902–1904 Scottish National This paper, building on work by many Antarctic Expedition. You might also other scientists in preceding years, remember that the last issue of The was arguably the crucial final step Edinburgh Geologist anticipated some in establishing the paradigm of plate celebration of ‘fifty years of plate tectonics, providing a unifying context tectonics’, following the Geological for Earth science.” So, there you have it, Society of London’s selection of last although I confess I’ve always hated the autumn to celebrate that anniversary. use of ‘paradigm’! So, when Ian Dalziel offered an article for EG that contrived to combine both It wasn’t long before the new ideas of those themes, how could I resist? were being applied to Scottish Ian’s account kicks off this issue of geology, and I’m pleased to see that EG. It might contain bad news for the a couple of John Dewey’s seminal Scottish expedition’s geographical papers are given prominence by Doug legacy, but it ably demonstrates the Fettes in our second article, which way in which plate tectonics has continues the plate tectonics theme. liberated the geological imagination Doug takes on the unenviable task and encouraged contemplation of of reviewing the impact of the new tectonic linkages — backed-up by paradigm (ouch!) on the perceived extraordinary technical advances — that relationships developed between the would undoubtedly have bemused our geological terranes of Scotland during predecessors. the Grampian Orogeny. And if you thought that Scottish geology was all The selection of the anniversary year done and dusted post-plate tectonics, might seem a bit arbitrary given the way read on; the Highland Border that the plate tectonics debate played- Complex seems particularly reluctant out in the late 1960s, but a rationale to give up its secrets. On the other was provided in Geoscientist, 27/11. hand, it was an appreciation of long- 1 EDITORIAL established geological features that hard to keep Hutton out of the pages made the application of plate tectonic of EG, although it’s his great friend, models possible in the first place. the chemist Joseph Black — or at least Whilst celebrating a 50th anniversary, Black’s tombstone in Greyfriars — that let’s not forget all that went before and features in Nina Morgan’s article, made the whole thing work. Here’s our third, wherein we discover why to basic data and the unsung pioneers Archibald Geikie spent so much who collected it all over the World. time hanging around in graveyards. Picking-up on that thread of ideas, Then what of those ‘bemused Andrew McMillan then chides predecessors’? What would the those responsible for the neglect of likes of James Hutton have made Hutton’s grave, close to Black’s in the of it all? These days, in the cosmic ‘Covenanters’ Prison’. microwave background we see a vestige of a big-bang-beginning, whilst Two book reviews complete this issue the prospect of an end for planet of EG. No ‘creative writing’ is on offer Earth, eventually, is well established. this time, but all would-be authors out But given the propensity of Hutton there should bear in mind the closing and his Enlightenment colleagues to date for this year’s ‘Hugh Miller ’follow the evidence’, I like to think writing competion’:15 April 2018. that they would have been right up Alternatively, if you are fired-up by the there, at the forefront of the new ill-named paradigm’s 50th anniversary, developments. Either way, it’s certainly you might consider having a go at the James Hutton (left) and Joseph Black — ‘Philosophers’ by John Kay (1787). Reproduced by permission of Sheila Szatkowski from her book Enlightenment Edinburgh — a guide (Berlinn, 2017). 2 EDITORIAL Geological Society of London’s ‘Plate Gatliff who has taken over the Society Tectonic Stories’ competition: see reins from Stuart Monro. Bob has a www.geolsoc.org.uk/tectonicstories, background in marine and petroleum closing date is 30 April 2018. And geology and geophysics with the something short and original for a British Geological Survey, but so far as future issue of EG might also be a I know has not established a media good idea. empire. Thinking of Hugh Miller, a fine statue of him, about two-thirds life-size, stands in the sculpture balcony, high above the Grand Gallery in the National Museum of Scotland. He stands gazing at a freshly-split specimen of the armoured Devonian placoderm fish Pterichthyodes milleri, held in his left hand with the counterpart lying at his feet; his right hand grips a small geological hammer. So far, so good, but go around the back and, sad to say, the hammer has no handle. There’s just an empty socket where one was once attached. Now, no field geologist, even when shrunk and set in stone, should be deprived of a functioning hammer, so I appeal to the museum management to put things to rights. A nice piece of hickory would not look amiss. Incidentally, a little further along the balcony is a bust of Charles Maclaren (1782–1866), a past-president of the Edinburgh Geological Society but perhaps better known as one of the The statue of Hugh Miller by Amelia founders of The Scotsman newspaper. Paton Hill (c.1860s) in the National Museum of Scotland’s sculpture Finally, from a past-president to our collection. It stands about 1.15 m new president, and welcome to Bob tall. 3 DID THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION DISCOVER A FRAGMENT OF NORTH AMERICA? Did the Scottish National Antarctic Expedition discover a fragment of North America? By Ian Dalziel On the 2nd of November 1902 the continent on the eastern side of members of the Scottish National the Weddell Sea and make the first Antarctic Expedition set sail from sighting of land there. the Firth of Clyde on board their Steam Yacht Scotia bound, according The Scottish National Antarctic to Expedition Leader Dr W S Expedition conducted the bathymetric Bruce, for: “one of the least known studies that linked the southernmost parts of the South Polar Regions” Andes to the Antarctic Peninsula …“While ‘Science’ was the talisman through the arcuate Scotia Ridge of the Expedition, ‘Scotland’ was enclosing the Scotia Sea (Bruce 1905; emblazoned on its flag” (Bruce 1906, Fig. 2). Its members also undertook p. vii–viii; Fig.1). Almost due south, extensive geological and glaciological but over 14 000 km distant, Scotia was work on the South Orkney Islands to reach the edge of the Antarctic and the Falkland Islands as well as Fig. 1 SY Scotia and expedition members, March 1904 while the vessel was beset in heavy pack ice at the most southerly point reached (74°1’S, 22°0’W). Glasgow Digital Library based at the University of Strathclyde. 4 DID THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION DISCOVER A FRAGMENT OF NORTH AMERICA? Fig. 2 “Bathymetric Survey of the South Atlantic Ocean and Weddell Sea” (Bruce, 1905), with place names superimposed by the author. marine biological studies (see Stone Sea, however, it faced a challenge 2017, and references therein). This unknown to Scots bound only contribution is concerned with for England — ice. At 72 degrees the identification and potential 18 minutes South, 17 degrees 59 significance of the ice-covered land minutes West “we were brought up that the Expedition discovered at the short”, wrote Pirie. They had reached southeastern corner of the Weddell what is now known as the Riiser- Sea. What exactly did they find? Larsen Ice Shelf (Fig. 3), “a lofty ice- barrier similar to that discovered by After completing their early Ross on the other side of the Pole: oceanographic work and a detailed it stretched in a north-easterly and geological survey of Laurie Island south-westerly direction” (Pirie 1906, in the South Orkney Islands, Scotia p. 234–235). According to Pirie, headed into the Weddell Sea. Bruce believed that the coast line Expedition geologist and surgeon of Antarctica must run more or less Dr J H Harvey Pirie wrote: “We continuously from there to Enderby were once again southward bound Land (50–60 degrees East longitude) – following the traditional policy of to account for the ice limits reached the inhabitants of Scotland….” (Pirie by Cook, Bellingshausen and others 1906, p.