The Edinburgh Geologist

Magazine of the Edinburgh Geological Society Issue No 62 Autumn 2017 The Edinburgh Geologist Issue 62 Autumn 2017

Cover Illustration Statue of St Michael, in white marble, in the east gable of St Mary and St Finnan’s Catholic Church, Glenfinnan, 1873–74. The church, designed by Edward Welby Pugin in the ‘late Early English’ style, attractively juxtaposes a variety of stone for the ashlar work – local blue-grey granitic- gneiss marbled with quartz combined with light pink Elgin freestone, the latter also being used for the window and door surrounds. Photograph by Andrew McMillan. For more on the use of building stone across the Scottish Highlands see Andrew’s article on page 4. BGS images are reproduced by permission of the British Geological Survey ©NERC. Published September 2017 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 SXEOLVKOHDÁHWVDQGH[FXUVLRQJXLGHV)RUPRUHLQIRUPDWLRQDERXWWKH6RFLHW\DQGPHPEHUVKLS please visit www.edinburghgeolsoc.org. EDITORIAL

Inspirational geology — what did it for you?

An editorial ramble by Phil Stone

Much of geology’s popular appeal lies tourism, but also highlights steps being in its fundamental framing of our ‘sense taken to redress that situation. of place’: our much-loved scenery and a cultural landscape influenced by local Or perhaps it was fossils that first natural resources. If that’s your kind of got you into geology. If so, there’s geology then you will enjoy our first two a good chance that once upon a articles in this issue of The Edinburgh time you collected a few of them. Geologist. First, Andrew McMillan Whether your collection was completes his two-part review of scientifically well-organised or building stone use across the Highlands, accumulated along the random lines introduced by our cover picture, and of a ‘cabinet of curiosities’, you will as a bonus he has consolidated both have enjoyed them for the glimpse parts of the story into a single pdf that they provided of life in ages past. It will be available online as a supplement was not always thus. The recent small to EG62. In our second article, Angus exhibition at the National Museum Miller laments our neglect of Scotland’s of Scotland — Fossil Tales — took us geoheritage and its potential for back to a time when fossils were

The setting for our cover picture: St Mary and St Finnan’s Catholic Church, Glenfinnan. The church is a memorial chapel to the MacDonalds of Glenaladale, the family with whom Bonnie Prince Charlie stayed prior to the raising of the Jacobite standard at Glenfinnan in August 1745. Photograph by Andrew McMillan.

1 EDITORIAL endowed with mystic status and put ammonites and crinoids would have to some unexpected uses. Probably been relatively commonplace and so best-known of the fossil legends had were not perhaps endowed with mystic Saint Hild(a) (614–680 AD) petrifying powers beyond the benefits accruing the snakes of Whitby — and being from their religious association. Not so immortalised taxonomically for her up in the Highlands of Precambrian trouble with the ammonite genus Scotland where a fossil would have Hildoceras. To improve on her efforts, been a rare sight indeed. Judging by local entrepreneurs were soon carving the examples in the National Museum’s heads onto the fossil ammonites exhibition, echinoids in particular were even though the lack of heads was deemed to have notable supernatural ‘officially’ put down to a beheading value. So, for example, specimens of curse issued by St Cuthbert (634– the Cretaceous sea urchin Echinoconus 687 AD), who was also credited with were sold in 17th century Scotland as ‘beads’ — crinoid columnals claimed ‘stones of miraculous efficacy against to have been derived from his rosary. perils by fire and water’. And should your horse need treatment for an At least across the fossiliferous outcrops infestation of bot fly larvae here’s of Medieval, Mesozoic England what to do: take one belemnite and soak overnight in water, then let the horse drink the water. It’s not clear how many times you could reuse the same belemnite before the ‘palaeo- homeopathic’ effect wore off.

It’s easy to scoff at such superstition, but in these post-truth days of fake news and alternative facts it seems that we can all be susceptible to a belief in arrant nonsense. Healing crystals and the like are pretty harmless, but what of geology’s role in emotive and challeging topics such The Jurassic ammonite Dactylioceras as anthropogenic climate change ‘improved’ according to the myth or politically-sensitive estimates of of St Hild(a). https://commons. its scientific antithesis, Scotland’s wikimedia.org/wiki/File:Snakestone_ hydrocarbon potential? Fearlessly (and (15240494805).jpg with a fine specimen of Echinoconus

2 EDITORIAL at the ready), EG tackles the latter about how it all suddenly made issue with Professor Roy Thompson’s sense — and how we had to cope with assessment of whether fracking for a whole new vocabulary. Why not gas and oil can boost the Scottish share your memories in EG63. economy as North Sea hydrocarbon production declines. I’m sure that Of course, for another alternative not everyone will accept Roy’s introduction to geology you can’t conclusions — though hopefully beat a pebbly beach, and so it was for objecting on scientific grounds rather Gayle Maynard who provides, in our than wishful thinking — but one thing fourth contribution, an original — and I hope we can agree on is that there is perhaps autobiographical — view of a a very important difference between a conversion to geological appreciation. resource and a reserve: politicians and I’m grateful to Gayle for letting us media people please take note. publish her piece of creative writing in EG and hope that it stimulates Then again, for those of a certain age, more of us to try our hand at some it was the plate tectonic revolution geoliterature inspired by landscape, that fired-up a fascination for vernacular architecture, fossils, plate geological processes. Hard to believe tectonics or pebbly beaches, whatever that it all happened fifty years ago, it was that got you hooked onto with the Geological Society of London geology. If it was all of the above, and hosting a ‘Plate Tectonics at 50’ more, then you’ll certainly appreciate symposium in October this year. But Christine Thompson’s book review of perhaps it was only revolutionary from GeoBritannica: Geological landscapes the American perspective. For those and the British peoples that concludes of us brought up on Arthur Holmes’ this issue of The Edinburgh Geologist. Principles of Physical Geology a rather hazy concept of continental drift was References always lurking in the background. Peach, B N. 1912. The relation And the idea of the Atlantic closing between the Cambrian faunas of and then opening again wasn’t too Scotland and North America. Address shocking as we’d known about to the Geological Section of the British that curious, trans-Atlantic fossil Association for the Advancement of distribution since before the days Science, Dundee. of Ben Peach. Nonetheless, plate tectonics cut through the haze and Wilson, J T. 1966. Did the Atlantic geology was never the same again. close and then reopen? Nature, 211, Maybe you have some reminiscences 676–681.

3 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS

Geology and building stones in the Highlands and Islands Part 2 Igneous and crystalline metamorphic rocks

By Andrew McMillan

Following Part 1 (in The Edinburgh facilities and exposed structures such Geologist No. 61) this article covers as lighthouses. a selection of igneous and crystalline metamorphic rocks which have been Scottish granites range from traditionally used as building stone Neoproterozoic to late Palaeogene in in the Highlands and Islands. The age. Many were exploited locally as complete article (Parts 1 and 2 and a building material and setts. Today, full bibliography) appears online as granites are principally quarried for a supplement to this issue of The crushed rock aggregate but some Edinburgh Geologist. quarries are producing building stone. The principal granite quarries Igneous Rocks were in Aberdeenshire. Almost all Granite the significant quarries were coastal Granites occur throughout the or linked to a coastal port to facilitate Highlands and Islands but those export by sea. Granite was also of the Grampian Highlands are worked in Mull and Lochaber in especially important in relation to the the western highlands. Granite was building stone industry. Granite is a valued for its attractive appearance, quartz-rich, ferromagnesian mineral- with stone from the different regions poor intrusive plutonic igneous rock having different characteristics, for which varies in crystal size from example the deep red granite from medium- to coarse-grained. With Ross of Mull and Peterhead, the appropriate grinding and polishing salmon pink of Corrennie and the methods, it can be finished to a very silver grey varieties of Aberdeen. smooth surface making it a popular stone for monumental and decorative In Aberdeenshire from the 19th work. It is also hard, dense and century the granite industry was resistant to degradation by frost and of huge importance to the local sea water, which means that it was economy, and materials and skills commonly used for docks, harbour were so plentiful that much of the city

4 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS of Aberdeen was constructed from granite despite it being a difficult and expensive stone to work (most of the earliest buildings in the city are of more easily worked sandstone). Within the city, Rubislaw was pre- eminent. This quarry produced a greyish-blue fine-grained granite. It took a beautiful polish and was largely used for building and engineering Pink and grey granite in the former work as well as for monuments. St Columba’s Church, Inverdruie, Aviemore, now St Columba’s Rescue The major granite quarries in Base (Cairngorm Mountain Rescue). Aberdeenshire have a long pedigree Note the use of sandstone for of supplying stone for prestigious ornamental work, window surrounds buildings throughout the United and door arches. Kingdom and beyond. For example, the silver grey coloured granite from Kemnay was used for such diverse polished work and for heavy projects as the Forth Railway Bridge engineering projects. (1885) the Queen Victoria Memorial, London (1911–24) and, recently as Formerly there were many quarries in cladding for the Scottish Parliament Deeside particularly around Ballater (2004). Kemnay granite was largely and at Inver. Invergelder supplied used for building and monumental silver grey granite for Balmoral Castle purposes but also produced and other buildings on the Royal large numbers of setts. The most estates. Granite at Auchindryne, outstanding building constructed of Braemar was used for Mar Lodge. Kemnay granite is Marischal College, Aberdeen, the second largest granite The granite quarries in the western building in the world1. Quarries at Highlands, in particular those on the Peterhead and Longhaven including Ross of Mull and the Bonawe and the Stirlinghill Quarries produced Ballachulish quarries were directly reddish brown, coarse-grained on the coast, and were favoured granite, well adapted for both for for major construction projects architectural and monumental such as lighthouses and roadstone. Fine-grained Ben Cruachan granite 1 The largest is the Escorial Palace near Madrid — Ed. quarried at Bonawe was of excellent

5 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS quality for building purposes but was used in Oban as a building stone. also used for road setts. Close by, the It was characterised by numerous quarries at Craig worked a coarse- xenoliths of black schist which grained hornblende biotite granite detracted from its appearance. The which could be extracted in large nearby ‘black granite’ of Kentallen blocks and employed for harbour (‘kentallenite’) took a good polish work, ornamental purposes and for and was in much demand as an building stone. Granite boulders were ornamental stone for monuments. also used for building purposes. In the Northern Highlands, granites Tormore (Torr Mor), close to and diorites have been exploited Fionphort, Ross of Mull produced at several localities. Large glacially- the largest granite blocks in the UK at transported granite boulders often 16 m length, and some blocks were provided suitable resources for local exported to the United States. It was building purposes. In Strath Rusdale, used for dock works and bridges such in the Ben Wyvis district, it was said as Westminster Bridge and Blackfriars that one boulder was broken up to Bridge, London. The Ross of Mull provide more than enough stone for granite varies in colour from pale to two cottages. deep red. Other quarries included one, North Bay, on the north side In the mid-20th century, granite and of the Ross which was opened to granodiorite was used for hydroelectric supply stone for the Skerryvore and scheme constructions, both as fill and Ardnamurchan lighthouses. The older for facing. For example, the dam at parts of Iona Abbey and the nunnery Dundreggan, Invermoriston, largely are built of Ross of Mull granite (some derives from the Cluanie Granodiorite from boulders) and metamorphic pluton, and Strath Ossian granite was flagstone. It was reconstructed using worked in Glen Spean to provide granite from the Black Island Quarry, material for the Laggan dam. a name applied to two quarries at Dearg Phort on the Sound of Iona. Other igneous rocks Igneous rocks other than granite occur In Lochaber red granite was also widely throughout the Highlands and quarried in Glen Nevis for use in Fort on the Scottish islands, especially the William. The Strath Ossian Granitic Inner Hebrides including Mull and Complex provided local grey granite Skye. In recent years they have been for the estate. Resources of the grey extensively quarried, largely for use as Ballachulish Granite were largely aggregate and roadstone. A number of

6 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS quarries are still in production today Aberdeenshire have been exploited for this purpose. as a source of building stone (e.g. for Huntly Castle). Today gabbro is Basic igneous rocks have commonly an important source of crushed rock been exploited locally for building and aggregate (e.g. at Pitcaple, Inverurie). walling. Basalt of the British Tertiary Igneous Province on the western Ultrabasic rocks have been used seaboard forms an important and locally, as for example on Unst distinctive component of the built where the ochre-brown weathering heritage of the area and has been serpentinites and dunites (composed used as the principal rubble stone almost entirely of the ferro- in many medieval buildings on the magnesian silicate mineral olivine islands of Skye and Mull (see Part 1). and its weathering products) form such a characteristic feature of the brown landscape.

Basalt wall of the Skye Gathering Hall, Portree. Note the pink sandstone window surrounds.

Dolerite, coarser grained than basalt, was quarried at Inverlochy (near Dalmally) and used for houses in the district. Brown-weathering serpentinite- Gabbro usually forms some of the dunite has been used for the local coarsest basic igneous rocks. Many buildings of Baltasound, Unst, of the gabbroic and noritic masses of Shetland.

7 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS

Distinctive igneous rocks of felsic and the ease with which otherwise hard intermediate composition such as metamorphic rock types could be porphyritic microdiorite (porphyry), worked as building stone. Field microgranite, trachyte and syenite have stones (glacially-derived or from proved valuable sources for ornamental raised beaches) often formed the stone, setts and paving blocks (e.g. best building resource from the quartz porphyry from Furnace and earliest times. Over the last 200 years Crarae on Loch Fyne). Although many Highland estates opened small generally difficult to work, they were quarries to supply local needs for valued because of their durability and buildings and stone walls. attractive appearance — they range from fine- to coarse-grained and are strongly Gneiss or pale coloured. Where natural jointing Typically foliated (banded or striped) in the rocks is closely spaced, blocks gneisses are tough rocks, difficult to could be extracted both for sett-making work and to dress. Usually they do and building stone. An example of not readily split along the direction the latter is the pinkish syenite of of foliation (c.f. schist, below). As a the Ben Loyal intrusion which was consequence in the past gneiss was quarried and used for buildings in used traditionally as a local source Tongue and district, Sutherland. of building material either collected from fields as glacially derived boulders or locally quarried where the joint pattern has enabled slabs to be relatively easily removed. Perhaps the most famous examples of early building with gneiss are on the Island of Lewis. Here, the 5000 year old Standing Stones of Calanais comprise irregular slabs of Lewisian gneiss. Nearby smaller blocks of gneiss were employed in the dry stone walls of Ben Loyal Hotel, Tongue, built of Carloway Broch. Exceptionally, some Loch Loyal Syenite. gneisses split relatively easily as on Coll and Tiree where Lewisian gneiss Crystalline metamorphic rocks was used extensively as building As mentioned in Part 1, joint material. Likewise in Banffshire, spacing, cleavage and inherited gneiss was capable of being dressed bedding characteristics determined and was used locally.

8 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS

as ‘gritty schist’ or ‘schistose grit’ have been used for local building purposes. These rocks may have once been coarse grained sandstones, and although now metamorphosed some rocks may partially exhibit the original sedimentary texture.

A mixture of squared coursed psammite and banded gneiss, veined with quartz, forms the masonry of Invergarry Hotel, Inverness- shire. The more easily worked red sandstone forms window surrounds and carved work.

Skipness Chapel, Argyllshire, Schist rubblework of gritty mica schist with Schist (derived from the Greek red sandstone arch. schizo, split) is a coarse-grained, finely foliated (banded or striped) metamorphic crystalline rock. The Green Beds (chorite-schist) fine scale foliation (schistosity) results Green Beds (including epidote- and from the parallel arrangement of chlorite-schist) crop out as a belt lamellar minerals, most commonly of rocks from the Mull of Kintyre the micas. The schistosity enables the through Loch Lomond to Aberfoyle rock to be relatively easily split and and Aberfeldy. Typically green owing this characteristic has been exploited to the presence of the lamellar for a variety of purposes including mineral chlorite, the rocks are of rubblework, stone slabs for standing metasedimentary origin and have stones, gravestones. In Argyllshire been derived in part from basic Dalradian schist from Doide by volcanic sources. Because of their Loch Sween was used for sculpted ability to split well, green beds were stones from Medieval times. In some used for carved monuments including parts of the Grampian Highlands Celtic crosses of the Iona School as and western islands rocks described well as providing rubble for many

9 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS medieval castles and chapels. Green Beds were employed for the Tay Bridge at Aberfeldy, recently repaired. Quarries near Aberfeldy supplied that town and Pitlochry. Many small quarries were opened in both green beds and schists at Tarbet, Ardrishaig, Lochgilphead around Loch Fyne to supply local building needs.

The Cross of Kildonan, Island of Islay carved in chlorite-schist.

Catherine’s on Loch Fyne supplied Lochranza Castle, Isle of Arran. A tremolite- and chlorite-bearing gritty green chlorite-schist has been epidiorite for use in Inveraray and employed for the rubble-work with Inveraray Castle and estate buildings. soft pink Carboniferous sandstone Similar epidiorites were quarried at surrounding the doorway. Lochgilphead and Ardrishaig.

Marble The Highlands and Islands have Metavolcanic rocks (epidiorite) several true marbles (limestone Metamorphosed basic volcanic rocks recrystallised by metamorphism) including Dalradian metabasalts which, on account of their colour and crop out extensively in Argyllshire. other properties, were used primarily These green and black rocks have for decorative and monumental also been used as building stone over purposes. The decorative marbles the centuries. Quarries such as St are typically variably green-coloured

10 GEOLOGY AND BUILDING STONES IN THE HIGHLANDS AND ISLANDS serpentinite marbles with distinctive Building Stone Database for Scotland textures, although pink and blue which will offer a publicly accessible varieties also occur. Several of the web portal aimed at providing quarries were active intermittently some of the knowledge needed to from the 18th century, and most inform best practice in maintaining ceased production in the early 20th and conserving the country’s built century. Of the sources which have heritage assets. Readers interested in been used for monumental work, learning more about this project or perhaps the best known are from wishing to contribute to it are invited Tiree, Iona, Skye, Portsoy and Glen to contact the BGS Building Stones Tilt. Team whose work is described at http://www.bgs.ac.uk/mineralsUK/ Concluding remarks — conserving buildingStones/home.html. the heritage This brief and selective resumé of Bibliography (additional to the building stones of the Highlands references cited in Part 1) and Islands illustrates the wide Cameron, D G. et al. 2014. Directory variety of building stone materials of Mines and Quarries. Tenth Edition. which have been used through the Keyworth, Nottingham: British centuries. To assist our understanding Geological Survey. of the aesthetic, cultural, historic Diack, W. 1941–2. Rise and progress and economic (e.g. in terms of of the Granite Industry of Aberdeen. tourism) importance of stone in the , April built heritage, there is an ongoing The Quarry Managers’ Journal 1941- February 1942. need to record and characterise the various types of building stone Hyslop, E & Lott, G. 2007. Rock of which have been used, and attempt ages: the Story of British Granite. to identify and protect existing The Building Conservation Directory. or even new sources of matching Download from http://www. materials. This is not just for use buildingconservation.com/articles/ in repair and conservation, but, rockofages/rockofages.htm given a sufficiently viable supply McMillan, A A. 1997. market, indigenous natural stone Quarries of Historic Scotland Technical has the potential to be specified for Scotland. Advice Note 12. Edinburgh: Historic alterations for extensions to existing Scotland. buildings, and even for entire new- builds. In that regard, the British Andrew McMillan Geological Survey is developing a [email protected]

11 GEOTOURISM: PROMOTING SCOTLAND’S GEOLOGICAL STORIES

Geotourism: Promoting Scotland’s geological stories

By Angus Miller

Siccar Point, just 35 miles outside Edinburgh, is widely recognised as one of the world’s most important geological sites, and is well known and appreciated by generations of Edinburgh geologists. Although I’ve visited many times in recent years, I’m always greatly impressed by the wild coastal scenery and the dramatic exposure of James Hutton’s famous unconformity. Siccar Point is easier to find and appreciate than ever before, there are leaflets, signposts and interpretation boards. Even so, most days you are unlikely to meet more than a handful of people there; Visiting geologists from Chile enjoy visitors from overseas find it quite Hutton’s Unconformity at Siccar startling that we don’t shout more Point; a recent study has found that about our best geological asset. there are fewer than five visitors per Without a doubt, in many other day on average. countries a site as significant as this would have a visitor centre, rangers on duty and quite possibly even will take weeks! The recent 100 restricted access. Great Geosites project organised by the Geological Society of London Siccar Point is just one of Scotland’s demonstrated this, with 38 of the geological treasures, this is a country UK’s top geology sites in Scotland1. with unrivalled variety in a small geographical area. Everyone has ‘Geotourism’ encompasses two their favourites. Try to plan a trip audiences: (1) the general visitor, around Scotland that includes all who might be unaware of geology the geological highlights and very but enjoys the views and the scenery quickly you have an itinerary that of a place, and can deepen their

12 GEOTOURISM: PROMOTING SCOTLAND’S GEOLOGICAL STORIES appreciation of the landscape by For geologists and those interested learning about the stories behind in geology (which must number it, and (2) the more specialist millions of people around the world), visitor who already has an interest Scotland is often already on the and appreciation of geology and ‘bucket list’, through awareness is interested in visiting geological of James Hutton, or the Moine localities. There is an analogy in Thrust, or the volcanic variety of the recent interest in the restored sites such as Mull, Skye and Glen Flying Scotsman locomotive which Coe. I have worked recently with has drawn large crowds: the general groups of American visitors already public, who enjoy the spectacle of a interested in geology, who are willing working steam locomotive, but also to visit Scotland 2 or even 3 times the enthusiasts who understand the to explore our geological variety: underlying engineering and history one visit, even for two weeks, is not and get a huge thrill from the close enough! There is certainly potential personal experience. to do more to market Scotland as an international destination for the geo- Scotland has great potential for aware, encouraging people to visit geotourism in both markets. For ‘the home of geology’, to explore a the general visitor, we already very rich variety of geology in a small know that Scotland’s scenery is the geographical area, with links to many number one draw: sites such as aspects of the historical development Edinburgh’s Old Town, Staffa and of the science of geology. Skye are very popular, and these are places where the geology has a However, if we are to market direct influence on the key features Scotland as a geotourism destination, that draw the tourists. We can add resources are needed to support to this appeal by building on the more visitors. Are the current ‘sense of wonder’ that our landscape arrangements at Siccar Point inspires, explaining the underlying adequate? Across Scotland, a lot of story but also highlighting the links information and resources already from geology to scenery and culture. exist. There are a few visitor centres We can draw attention to the variety where geology is a primary focus of landscapes across Scotland to (such as Knockan Crag in the North encourage the general visitor to West Highlands Geopark), or where explore further, to extend their visits the local geology is explained as part beyond the hotspots of Edinburgh, of a wider introduction to an area Loch Ness and Skye. (as at the excellent Atlantic Islands

13 GEOTOURISM: PROMOTING SCOTLAND’S GEOLOGICAL STORIES

Centre on the island of Luing, south of the landscapes and places. One of Oban). There is a wide range particularly poor example (ironically in of published material: excursion a Geopark) is the roadside information guides, books, maps, leaflets and panels provided by the National some web content. Around Scotland Trust for Scotland in Glen Coe that there are many interpretation incorrectly describe many aspects of boards with geological information. Glen Coe’s geological history. The Edinburgh Geological Society certainly plays a part in this, with our long history of publishing Excursion Guides (much of the content now available for free from the Earthwise website2), some information boards (including one in Princes Street Gardens) and more recently the efforts of our Geoconservation Groups to produce leaflets about local sites, that are distributed via local outlets and the EGS website.

So there is plenty of information available, but the distribution is Interpretation board at Glen Coe patchy and the level of information that misses the point that the (and its accuracy) is variable. The surrounding peaks of volcanic rock three existing Geoparks in Shetland, formed in major caldera-forming Northwest Highlands and Lochaber eruptions involving significant stand out as exemplars of what can subsidence — and gives an age that is be done when local communities 50 million years too old. engage with their geology: organising events, running visitor centres and creating interpretive material that Of course, information or is available in a range of formats interpretation needs to be aimed at a for a variety of audiences. But specific audience — no one product away from these hotspots, many of will be suitable for all. The Knockan Scotland’s best geological sites have Crag Visitor Centre is one of the jewels no appropriate information either at of interpreting Scotland’s geology, the site or online to encourage people located by a main road in the Moine to visit and explore the rich stories Thrust Zone, and it illustrates the issue

14 GEOTOURISM: PROMOTING SCOTLAND’S GEOLOGICAL STORIES very well. It is very popular, the car park is often busy and tour buses from cruise ships that call into Ullapool routinely stop there. I’ve heard positive comments from many people, including those who profess to know nothing about geology. The mix of scenery, geology and the history of science appeals, and it is presented in an engaging way — clearly this centre is successful in explaining and interpreting the local landscape Face to face with Peach and Horne at and telling the historical story of the the Knockan Crag visitor centre. discovery of the Moine Thrust and the development of ideas about mountain building processes. There is a good year we have secured funding from case to be made that other geological the Heritage Lottery Fund for a project sites in Scotland should have similar that is part of the Year of History, investment in interpretation. However, Heritage and Archaeology 2017. this style of sharing Scotland’s geology The aim is to celebrate Scotland’s isn’t for everyone, and the Knockan geological heritage by providing Centre has been accused of dumbing high-quality information about a down the story of the Moine Thrust. network of places across Scotland Different content and styles of where people can see the best of interpretation are needed for different Scotland’s geology, and organising audiences. a Geoheritage Festival throughout October. For now, we are focusing When the Scottish Geodiversity Forum efforts on a list of the 50 “best places was established in 2011, one of our to see Scotland’s geology”. Of course, aims was to bring people together this is a list with potentially hundreds to promote Scotland’s geology. The of entries: it was impossible to agree Forum took over the running of on a list of just 50 places, but with scottishgeology.com and has worked much compromise we have selected to encourage better promotion of 51! This is a very different list from the Scotland’s geology through Scotland’s 100 Great Geosites, because it has a Geodiversity Charter, workshops, different focus: these are places where conferences and projects such as the people can see and enjoy Scotland’s Hugh Miller Writing Competition. This geological story, so the geology

15 GEOTOURISM: PROMOTING SCOTLAND’S GEOLOGICAL STORIES needs to be easy to appreciate and be making little progress, as can be understand. We also wanted sites seen by the continued struggle to that are already routinely visited by properly fund Scotland’s Geoparks. people, that are accessible (which Recently Geoparks around the world discounted St Kilda and the west have been given a significant new coast of Jura, for example). Finally, we UNESCO designation, so that they wanted the selection to have good are now called UNESCO Global geographical coverage of the whole of Geoparks. This is major step that Scotland, from Unst to Southerness, will have an impact internationally and to cover all aspects of Scotland’s and has great potential to draw geology including glaciation and active visitors to these areas. However, processes. Scotland seems to be turning its back on this new designation. The 51 Best Places to see Scotland’s Despite widespread local community geology will be launched in October support and great efforts to develop 2017 with high-quality, introductory income streams, there is no interest information about each place, from the Scottish Government in accompanied by good illustrations, committing the relatively small on scottishgeology.com3. Throughout amount of on-going funding that October, there will be more than will secure the Geoparks’ future. 30 events across Scotland that will Positive developments on the Isle promote these places, encourage of Arran (where local organisations people to visit, and raise awareness are enthusiastically investigating of Scotland’s great geological stories. the potential of becoming a new The information being prepared Geopark with the backing of North is very much aimed at the general Ayrshire and Arran Council) are offset public, but it will include links to by uncertain futures elsewhere. further information. So it will provide a good overview of Scotland’s So, there is much work to do to geology for local people and visitors, provide information and resources and highlight ways in which people to enable local people and visitors can find out more. to better appreciate Scotland’s geology. The potential rewards, Clearly there is still a long way to economically and culturally, are go before there is uniform provision great. As well as boosting the tourist of interpretation of Scotland’s economy by encouraging more visits geology for the different potential and spreading the current tourism audiences. Sometimes we seem to bonanza beyond the hotspots, there

16 GEOTOURISM: PROMOTING SCOTLAND’S GEOLOGICAL STORIES are more subtle rewards when So, if you’ve ever shaken your head communities discover a sense of in disbelief at an interpretation board place and a pride in their geological that misses an obvious story about local heritage. Is there widespread geology, or visited an internationally awareness of these potential rewards? important site such as Siccar Point Definitely not! However, it is quite and wondered where all the other easy to understand why this is when visitors are, or seen someone’s eyes there is general ignorance about light up when they discover you know the richness of our geological story: something about geology and might ask any young person educated in just be able to answer a question Scotland how much they have been about the rock they’ve found or the taught about Scotland’s geology mountain they’ve climbed — get or our geological pioneers such involved! There are many different as James Hutton. There are many aspects of the challenge of promoting people fascinated and engaged with Scotland’s geology, and plenty of ways Scotland’s geology, but very few of for individuals and organisations to them have had that interest ignited in make a difference and contribute to our formal education system. the economic and cultural benefits of geotourism.

Further information 1. https://www.geolsoc.org. uk/100geosites

2. http://earthwise.bgs.ac.uk/index. php/Category:Edinburgh_Geological_ Society

3. http://www.scottishgeology.com/ where-to-go/ Geotourism in action at Hutton’s Section in Edinburgh’s Holyrood Angus Miller is Chair of the Scottish Park. Scotland has much to offer Geodiversity Forum and runs his geotourists, from the ‘sense of own business — Geowalks — offering wonder’ of the general visitor engaged walks and tours exploring Scotland’s by Scotland’s magnificent scenery, to geology. those with specialist interest drawn to the ‘home of geology’. [email protected]

17 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY?

Can fracking, for gas and oil, power the Scottish economy?

By Roy Thompson, GeoSciences, Edinburgh University

“Scotland[‘s] set for [an] oil bonanza furnace. Works were established at that heralds a new golden age for the Bathgate where local, exceptionally North Sea lasting for another century” high-yielding, cannel coals formed Independent Scottish business the basis of the new industry. pressure group (N56). Soon, when the coals ran out, Young “There can be little doubt that Scotland switched to the more extensive, but is moving into a second oil boom” Alex lower-yielding, underlying oil shales. Salmond, Scotland’s First Minister Production was initially on a small (2007–2014). scale. Nevertheless the oil-shale industry prospered. There are more These are bold, long-term than 187 old shale mines and pits in pronouncements made during the Scotland, and at least 142 abandoned run-up to the referendum on Scottish works where retorting, distillation and independence in 2014. Are they refining once took place. The vast realistic? Before discussing their veracity majority of these enterprises remained and reliability this short article positions small in scale and short-lived. Yet the quotes within a geological context production prospered, improved by summarizing the history and utility retorts were introduced and by 1865 of Scotland’s earlier oil booms. the industry employed 30–40 000

Shale oil The first commercial oil-works in the Oil shale is an organic-rich, fine- world were established in Scotland grained sedimentary rock. In Scotland the main oil-shale sequences occur by James ‘Paraffin’ Young. His venture th in Lower Carboniferous rocks. began on Thursday 17 October Solid remains of freshwater algae 1850 when he took out a patent for accumulated in a shallow lake the low-temperature distillation of complex lying near the equator. The coal and shale. Young had discovered lake basin occupied most of what is how to obtain paraffin oil and now West Lothian, extending at times paraffin wax by heating rocks in a into Fife, Midlothian and Lanarkshire.

18 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY? people. Production eventually peaked from ‘bagging’ Munros, has bagged in 1912 when more than three all 21 surviving bings. million tonnes of shale were mined to yield 1.7 million barrels of crude oil Oil and gas and over 54 000 tons of sulphate of Scotland’s next golden oil age opened ammonia. Eventually Scotland’s first in December 1969, with the surprise golden age of oil came to an abrupt discovery of the Montrose oil field. An end in 1962, with the closure of the Amoco-led group had actually been Westwood oil works. prospecting for gas 130 miles east of Aberdeen, but struck oil instead. Today, all that remains of the vast, old Soon afterwards the truly giant oil workings are faded warning notices, fields of Forties, Ekofisk and Brent one old office building and a few were proven, confirming that the miners’ rows. No furnaces. No retorts. North Sea would become one of the No industrial buildings. Much of the world’s great petroleum provinces. waste, however, endures to form The tectonic history, which gave rise to the area’s unique red slag-heaps, or the oil, was dominated by an episode bings. The burnt shale-debris rapidly of late Jurassic to earliest Cretaceous weathers to leave a surprisingly free- crustal extension. In broad terms the draining, cohesive substrate and rifting related to the breakup of the unexpectedly steep, yet stable, slopes. supercontinent of Pangaea. For many years saving the abandoned oil-shale workings has not been a As is well known, conventional top priority for local communities. petroleum systems require an Recently, however, an excellent organic-rich source rock which, when museum has been established as geothermally heated by burial, can part of the Almond Valley Heritage generate hydrocarbons; a reservoir, Centre. Also several bings have been composed of a porous unit, in landscaped and reclaimed as green which oil or gas can accumulate; space. Two, Broxburn (the Ayers Rock and lastly an effective seal, which lookalike) and the Five Sisters, are prevents hydrocarbon escape. While today legally protected as Scheduled the source rock responsible for Ancient Monuments and their virtually all of Scotland’s offshore vegetation left to regenerate naturally. hydrocarbons is straightforward — the The unusual setting and nature of Kimmeridge Clay — the reservoirs these exhausted industrial landscapes are exceedingly varied. Some are provide attractive areas for walking. So structural, others sedimentological. much so that the author, as a change Some reservoir rocks pre-date the

19 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY?

Kimmeridge Clay. This high-yielding Scotland’s fields were quickly brought source rock, of late Jurassic to earliest on-stream using innovative financial Cretaceous age, was deposited as investment vehicles, specially tailored mudstone and siltstone in land-locked to cope with the very risky milieu of marine basins. When sufficiently deeply offshore drilling, and skilfully conjured buried the organic remains (principally up by coalitions of accountants, dead plankton) become heated to bankers and lawyers. temperatures of 50–150°C and start to be thermally broken down to produce Oil first arrived onshore in 1975. oil. The Kimmeridgian is also notable in Complete production profiles are the USA as an important unit for shale- plotted in Figure 1. The overall double gas fracking. The Haynesville Shale in East Texas and Louisiana is a prime peak, and intermediate slump, is example with close similarities to the often attributed to fluctuations in North Sea source rocks. the price of oil. But this cannot be, as corresponding behaviour is not found for Danish or Norwegian fields. source rocks, the two having been Instead the dip relates to repercussions juxtaposed by later faulting episodes. following the Piper Alpha disaster Others are contemporaneous; yet in 1988, when UK oil production more as young as Eocene. Most was deliberately cut back in order to reservoirs are sands but deposited allow extensive work programmes to in an astonishingly diverse array implement new safety measures. of marine settings and capped by various impermeable layers. Once due allowance is made for the Piper Alpha effect the North Sea can All these reservoirs and traps have be seen to be a mature basin. Today had to be accurately pinpointed while the most straightforward way to assess buried beneath thousands of feet Scotland’s likely remaining offshore oil of overlying rock. Many North Sea wealth is a forward projection of the reservoirs are very small, in area no data of Figure 1. Using this approach I bigger than a town. Drilling is the final estimate an ultimate resource of 31 x arbiter of the likely productivity of oil 109 Bbl, with 11% still remaining to be and gas plays, but arguably the most recovered over the next decade. My important tool for exploring the North total coincides closely with geologically Sea and for gaining an impression grounded estimates, dating as far back of the subsurface has been detailed as the mid-1990s, which were based seismic imaging and interpretation. on field-by-field appraisals of the Following an initial exploration phase, porous volume of reservoir sands.

20 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY?

shale formations, and to liberate it by creating a dense network of connected spidery cracks by injecting fluid under high pressures (of up to 500 bar) and high flow rates (upwards of 50 gallons/sec).

On the environmental side, the evidence of the risks and benefits of fracking is fiercely disputed. Much of the furore, in the USA, has been driven by the lack of detailed chemical disclosure of hydraulic fracturing Figure 1 Offshore oil production fluids. A typical US well costs around for 261 UK fields (1975–2016). Each $8 million to drill, plus a similar sum coloured ‘stripe’ shows a different during the production phase. Fracking field. Note the steady fall in both involves injecting 5 million gallons field size and field longevity over of water (obtained from rivers, lakes, time. Buzzard (first oil, 2007) is the public water supplies or retreatment only notable exception. Accordingly, plants) plus proppants to keep incipient recently discovered fields have fractures open, plus 15 000 gallons of typically generated <10 million Bbl of recoverable oil with lifespans of <16 years.

Shale gas In the United States the recent advent of extended-reach drilling and hydrofracturing has opened vast new energy sources, such as black shales, and has significantly altered the domestic energy landscape (Figure 2). As an alternative to our dwindling North Sea oil supplies, Figure 2 Aerial view (B. Gordon, equivalent sources are currently EcoFlight) of hydraulic fracking being sought in Scotland. Companies pads. Looking north across part of want to drill beneath the Central Belt the Jonah tight gas field (of Late for gas trapped within Carboniferous Cretaceous age) in Wyoming.

21 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY? other chemicals. Hydrochloric acid is Glossary added to help clear out cement debris Bbl*: Blue barrel (1Bbl = 0.14 tonnes) in the wellbore. In addition gelation Gas-in-place: Modelled estimate of the agents, which improve proppant total volume of gas stored in a reservoir. placement, friction reducers, corrosion Reserve: Volume of hydrocarbons that inhibitors, an iron precipitation can be profitably extracted from a control, disinfectant biocides to control reservoir using existing technology. bacterial growth, oxygen scavengers Resource: Hydrocarbons that may and scale inhibitors are all basic eventually become producible. additives. Includes reserves as well as known oil and gas deposits that currently cannot A second major anxiety is be technologically or economically earthquakes. Interestingly, induced recovered, and even guesstimates of quakes are not necessarily caused undiscovered potential reserves. by the fracking process itself, but by tcf*: Trillion cubic feet. the disposal of the huge volumes of *: Americanized Imperial units reign flow-back and brine-laden waters supreme in the petroleum industry. produced along with the gas. In the US and Canada wastewaters addition faults are encountered every are disposed of in deep wells. This ½ mile or so. Figure 3 provides an practice serves to separate the waste example. In this abandoned opencast from drinking supplies but it can have section a syncline plunges into the secondary consequences. Since the photograph, decreases upwards in start of wide-spread fracking, felt fold-amplitude, is shifted laterally earthquakes have become hundreds by a fault, and is interrupted by a of times more common. The reason lava. Such profound discontinuities is that the wastewater disposal must inevitably create difficulties reactivates old, deep-seated fault during extended-reach fracking and lines. Further worries are greenhouse- lead to well underperformance. gas emissions and leakage. Furthermore Scotland’s low thermal gradient (22–30°C/km) and weak Local geology introduces additional Tertiary exhumation history suggest snags. The structural geology of the the great majority of its shales, with Central Belt is not straightforward. the possible exception of those The Carboniferous strata lie in a contained within deep synclines (e.g. series of small sub-basins and can Clackmannan, Midlothian-Leven, be subject to remarkably abrupt Solway), will barely have reached and extensive lateral change. In gas-generating temperatures.

22 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY?

viable means of generating a US-style shale gas industry in Scotland? The number of hydraulically fractured wells in the US is thought to have reached over 200 000. Gas-in-place estimates for Scotland broadly cover an area stretching from Glasgow & Motherwell, to Stirling & Falkirk, across half of Fife to Pittenweem, and then south through East Lothian to Penicuik. How can that Figure 3 Carboniferous shales and heavily populated area, of around 800 coals in a plunging syncline (yellow sq. mile, possibly be fracked from just curve) at Westfield opencast site 20 pads? The effective footprint that (nr. Glenrothes). A lava (blue oval) can be hydraulically stimulated from underlies the coals just beyond a a single pad in Scotland is likely to strike-slip fault (red dashes). BGS be small on account of the complex image P000196. geology, inconsistent stress field and geo-mechanical incompatibility of extended-reach drilling with shallow How could Scottish shale gas be targets. I envisage an efficiently accessed? KPMG, in their recent designed, Scottish, multi-well pad report for the Scottish Government on would drain an area of around one unconventional gas extraction, adopt a sq. mile, as in recent pad placements central estimate of 20 pads generating in Tioga County, Pennsylvania or up to £6.5 billion of investment and Septimus-Montney, Canada. creating 1400 jobs. Pads are areas of up to about 8 acres, which when In Scotland matters are rapidly coming cleared and levelled, would house the to a head. The Scottish Government drilling equipment and the enormous is currently promising to take “a final assemblage of pumps, diesel engines, decision [on the future of fracking] fleets of water trucks and sand mixers by the end of 2017”. But what, needed, along with wastewater despite the environmental risks, impoundment dams. Pads have appeal might the potential economic and as they concentrate industrial activity, fuel-security benefits be? The total so reducing the total noise, traffic in-place gas resource estimated for movements, surface disturbance, and Carboniferous shales is 49.4–134.6 number of access roads and utility tcf, with an additional oil-in-place corridors. But are 20 pads really a resource of 3.2–11.2 x 109 Bbl. To

23 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY? me the key question is not the size of In comparison to Scotland, the North the technically recoverable resource, of England has a gas resource estimated but what is a realistic assessment of at 1300 tcf. Its simpler geology with future deliverability. In short, how can deeper, thicker shales corresponds the reserve rather than the resource reasonably well with superior US be physically estimated using current provinces. Consequently if fracking is geological knowledge to the full? not commercially viable in the North I suggest the best methodology is of England it certainly won’t be in to employ an analogue approach. Scotland. The Scottish Government Production-decline curves, for other would be well advised to wait and see parts of the world, when combined what happens south of the border. with an appraisal of the key geological parameters which control recovery, A new golden age? allow the reserve to be quantified. In conclusion I return to the concerns broached at the outset. If geological My results, for gas yield per unit area, estimates of Scotland’s remaining are summarised in Figure 4. Note offshore oil reserves and of prospects the crucial control of depth on total for onshore gas are both so poor, production. Depths should be neither how can the N56 view that Scotland too shallow (too cool for effective gas generation), nor too deep (methane and other hydrocarbon gases formed, but broken down leaving nonhydrocarbon gases (CO2, N2, H2S) and depleted residues (pyrobitumen)). The diagram shows how Scottish shales with their modest organic carbon contents and shallow depths, not to mention their unremarkable thermal history and heavy faulting, barely correspond to even the poorest US-producing regions (e.g. Lewis, Conasauga, Ohio). Furthermore their frackability (ease of cracking Figure 4 Depth vs. total organic or fracturing) remains unproven content. Contours (red lines) of but could well be slight on account estimated ultimate recovery (Bcf/ of their low quartz-plus-dolomite sq. mile) in 24 US shale-systems. content. All in all Scottish shales may Systems outwith the black dotted well have a success factor of zero. polygon.

24 CAN FRACKING, FOR GAS AND OIL, POWER THE SCOTTISH ECONOMY? is set for a new black-gold bonanza and deep-water. As a consequence of an additional 24 x 109 barrels of expensive Scottish hydrocarbon is conventional reserves, plus a further not going to suddenly become in 21 x 109 from unconventional (i.e. demand. fracked) sources, be tenable? It can’t. Coal-bed methane The reason for the huge gap in Finally it is worth noting that coal expectations is twofold. First the N56 formations, if saturated with water, think-tank presented no geotechnical can contain copious amounts of evidence, from either drilling or methane gas adsorbed onto mineral production tests, for major new surfaces. The methane desorbs if conventional reserves anywhere the water is pumped off the coals offshore. Secondly they asserted and the gas can then be accessed by that the offshore Kimmeridge Clay production wells, often with minimal Formation can be fracked. Yes, the recourse to fracking. The potential Kimmeridge is a rich, hybrid source for coal-bed methane, as opposed rock. Yes, at 15 000 ft. below the to underground coal gasification central North Sea graben it can (which Scottish Ministers have contain abundant oil and gas-in- determined will have no place in place. But no, that does not make Scotland’s energy mix at this time), it an offshore reserve with any appears to be locally very promising likelihood of becoming commercially for the few relatively thick coal seams recoverable within a reasonable time that escaped 19th and 20th century frame. The economics of offshore mining. It would be a fascinating fracking are particularly bad. First, a happenstance if a 21st century top-rate US-style shale well typically source of hydrocarbon, in Scotland, yields only about 1/25th of a UK oil returned us full circle to Young’s well. On top of that fracturing costs original, masterly idea of generating considerably more than conventional hydrocarbons from coal. drilling, especially offshore. Lastly, when faced by such hefty economic Additional information, data disparities an appeal to an increase sources and references in oil prices does not provide a way http://www.geos.ed.ac.uk/homes/ out. Remember there are many thompson/ developmental possibilities, if oil prices rise, for virgin giant fields Roy Thompson, around the globe, especially subsalt GeoSciences, Edinburgh University

25 THE ETERNAL STUDENT AND THE KEEPER OF TIME — A DIALOGUE

The Eternal Student and The Keeper of Time — A dialogue

By Gayle Maynard

Eternal Student: I cannot lie... It was and pinks, caused them all to swirl and my love of pebbles. swish together, then left it there for me to see. Keeper of Time: What was? A masterpiece!

Eternal Student: The reason I took Keeper of Time: And so... the time, of course. Isn’t that why I’m here? Eternal Student: And so I had to know! I had to understand how this Keeper of Time: Please continue. It had come to be. was your love of pebbles... Keeper of Time: And so you chose... I Eternal Student: Yes. Red ones, see from my records here, to take some brown, speckled, time Monday afternoons “exploring the grey with streaks of white, geology of Scotland’s coast”. smooth and shining at the water’s edge, then baking in the sun. Eternal Student: Indeed.

Keeper of Time: Go on. Keeper of Time: And?

Eternal Student: The time — a Eternal Student: Yes? summer’s day, the scene — Ardlamont Bay with Arran Keeper of Time: And can you give a in the distance... satisfactory account of the time spent? Such beautiful stones! Have you anything more to say? And as I walked I came across one large and broad... Eternal Student: (dreamily) And and fluid! broken up by ice and flood and wave... It was as if some Hand had taken greys and whites Keeper of Time: I don’t follow.

26 THE ETERNAL STUDENT AND THE KEEPER OF TIME — A DIALOGUE

Eternal Student: I was just thinking it Eternal Student: Perhaps. might make a good line for a poem. I’m awed by the forces in nature to Keeper of Time: Have you more to change landscapes and... well... to say before I close this record? create... pebbles. Indeed, pebbles in all their humble Eternal Student: Just that I dreamt the glory are evidence of past energy, stones had lived... bodies acted on and changed! Igneous, sedimentary, metamorphic Amazing! and their hearts’ substance, the minerals which met, combined and By the way, did you know they say the danced together: earth is billions of years old? – in burning frenzy, igneous; – sedimentary, slow pas de deux of Keeper of Time: I know a lot of things. passing partners; – metamorphic, the contortionists’ Eternal Student: And of course there bolero. was Siccar Point. It was time well spent. Keeper of Time: Yes? Keeper of Time: I shall add it to the Eternal Student: Part of the sea’s record. old bed, displaced by ructious parts beneath to form the start of uplands. -----oooo----- So, exposed and pushed, colliding with and joining then the land that was, In 2014 Gayle did a short course on none guessed into its ancient past ‘the Geology of Scotland’s Coast’, … till Hutton, of course. part of Edinburgh University’s Open Learning (taught by Angus Miller). The A singular man that James Hutton and above was her submission for that an Edinburgh man, you know. year’s Martha Hamilton (Open Studies) Writing Competition, for which she Keeper of Time: That seems beside received third prize. the point.

27 BOOK REVIEW

Book review

GeoBritannica: Geological themselves have been conscious of, landscapes and the British peoples and mentally shaped by, landscapes by Mike Leeder & Joy Lawlor. from their earliest years, one Dunedin Academic Press, Edinburgh. becoming an academic geologist, the 2017. Hardback, 281 pp. Price other an artist, art teacher and English £24.99. ISBN 978-1-78046-060-4 graduate. The book is a collaborative attempt to marry Britain’s geological past, landscapes and raw materials with the social, industrial and artistic history of its inhabitants. It is written for those interested in both the sciences and arts and assumes a basic secondary-school knowledge of geology, history and culture. Its antecedents include such classics as A E Trueman’s Geology and Scenery in England and Wales and A Land by GeoBritannicaBritannica bbyy LeedLeederer & LLawlorawlor Jacquetta Hawkes, both published is an attractive book, beautifully over half a century ago, and more illustrated with high-quality and well- recent accounts such as The Hidden chosen photographs, together with Landscape by Richard Fortey. eye-catching maps and diagrams. It immediately makes one want to pick The book is divided into seven parts it up and devour its contents. and 34 chapters. Part 1 introduces the book’s main themes: the richness Within its glossy covers is an account and diversity of Britain’s landscapes; of the geological foundations of the the British peoples’ relationships many and varied landscapes of the with landscapes and the underlying island of Great Britain, which the geology; the rise of scientific authors call ‘the Island’. But that is enquiry into the Earth’s origins and not all: it is also about the influence development; and geology and of Britain’s geology on the daily life, landscape as represented in works work and creativity of the generations of creativity. Part 2 then recounts of people who have lived here how, through objective observations since the last glaciation. The authors in the field, geological maps

28 BOOK REVIEW were made and how subsequent geological heritage and the sum of developments, such as radiometric human activity on this island? They dating techniques, greatly clarified certainly do; and GeoBritannica the length, complexity and causal should bring geoscience to life for processes of Earth’s history. Part 3 non-scientists while showing scientists follows with an account of Britain’s that one can appreciate and interpret geological history, set in the context the natural world through feeling as of plate tectonics and the Pleistocene well as through analysis. glaciations, and plentifully illustrated with maps and reconstructions. I do, however, have some criticisms. Non-geologists will struggle with Parts 4 and 5 look at Britain’s some of the terminology and geological resources and how they complexities of British geology. have underpinned Britain’s economy, Although there is a glossary, some of shaped communities and inspired its definitions lack clarity. There are literature, sculpture and painting. The small but unsettling inaccuracies, constructional and artistic activities such as the attribution of the Iron of Britain’s inhabitants are discussed Bridge to Thomas Telford or the in Part 6. Here it is argued that not confusion of the Scott Monument only has our creativity been inspired with the statue it houses. Some by landscape but our appreciation of geological maps and cross-sections landscape has in turn been shaped by require so many colours that it is the works of architects and builders, difficult to distinguish all the shades sculptors, painters and writers. Finally, and hence reliably identify the rocks in Part 7, Great Britain is divided they represent. The text is sometimes into seventeen ‘GeoRegions’, each irritating, for example in its use of one the subject of a chapter in unfamiliar words (‘corried’, ‘riffing’), which its geology and landscapes and occasionally baffling, as in the are summarised, together with the analogy drawn between Anglesey essence of its human heritage. These and Orkney in Chapter 30. Careful chapters are brief appetisers, to editing would have picked up on be sampled when planning a visit, these and other minor flaws in perhaps, to an unfamiliar area of what is otherwise a highly unusual, Britain. An extensive bibliography enlightening and thought-provoking provides more detail. book. Read it and have your horizons expanded. Do the authors draw a convincing connection between Britain’s Christine Thompson

29 This issue: No. 62, Autumn 2017

1 Editorial ramble Inspirational geology — what did it for you?

4 Geology and building stones in the Highlands and Islands Part 2 Igneous and crystalline metamorphic rocks By Andrew McMillan

12 Geotourism: Promoting Scotland’s geological stories By Angus Miller

18 Can fracking, for gas and oil, power the Scottish economy? By Roy Thompson

26 The Eternal Student and The Keeper of Time — A dialogue By Gayle Maynard

28 Book review GeoBritannica: Geological landscapes and the British peoples

All previous issues are available online at www.edinburghgeolsoc.org/publications.

ISSN 0265-7244