#8 Britain’s Only Carbonatite


(A brief introfuction to the Loch Borralan Carbonatite)

Between the NE shore of Loch Urigill and Loch Borralan lies Britain’s only carbonatite pluton. The presence of a carbonatite in the Assynt area was first reported to the geological community by Young, Parsons and Threadgould in 1994 . The pluton was actually discovered by an undergraduate from the University of Aberdeen in the late 1980s who was mapping in the area. He puzzled over the rocks and eventually was bold enough to confront his supervisors about it. Sure enough, his speculation was soon corroborated and a fuller investigation was launched.

So what is known about the carbonatite? Well there has been relatively little work conducted on it since it was reported in the Journal of the Geological Society of London in 1994. It was reported that there are 4 varieties that occur:

1. porphyritic white sövite
2. phlogopite sövite
3. sövite breccia
4. foliated silicocarbonatite

The latter of three of the four types above were only observed in situ after part of the pluton was excavated. Since then mineralogical and whole rock analyses were conducted on the four different lithologies. Those chemical analyses revealed that the Loch Borralan carbonatite is chemically and isotopically (carbon) distinct from the surrounding Durness Dolomites in which the pluton is enveloped.

There are many unanswered questions about the pluton. Amazingly, there has been little interest in the body since the mid 1990s. I visited the carbonatite earlier this summer, and collected a sample of the porphyritic sövite. A thin section of this has revealed some interesting minerals which I am in the process of having analysed. Hopefully a report into further findings in the mineralogy of the body will follow some time next year.

A sample of Sövite from the Loch Borralan Carbonatite, showing well equilibrated calcites amongst some other as yet unidentified minerals.

Advertisements

7 thoughts on “#8 Britain’s Only Carbonatite

  1. It was a postgrad from Aberdeen University that found it – Supervisor had gone to Edinburgh. There was no interest in the thing economically – Utter lack of interesting elements.. so no further research. Other minerals in the slide probably Apatite and Chondrodite (Brownish yellow)

    • Barry, don’t know if you knew him. Barry Dawson, who was the first to map and describe the worlds only active carbonatite volcano, passed away at the end of last week. He passed quickly and peacefully at home. He was a great friend and inspiration.

      Regards

      Darren

      • Hi Darren

        That is really sad news – I met Barry several times when I was a PostGrad. He was fascinated and happy that a carbonatite had finally been found in the UK. His work was an inspiration to me before I started working on the Assynt rocks, so to actually meet and talk to him in person later was like meeting a hero :^)

        Thanks for telling me.

        Regards

        Barry

        Dr Barry Young | Operations Technical Support Engineer
        Baker Hughes | Operations/UK/MWD
        Office : +44 1224 359535
        Mobile: +44 7808 976 279 | barry.young@bakerhughes.com
        http://www.bakerhughes.com | Advancing Reservoir Performance

      • Not a problem, I thought that given that carbonatites are such rare lithologies that those that know about them probably know each other in some form.

        Barry was an unofficial supervisor for my PhD, but was a good friend and mentor. The weekend before his death he and I were at a conference together in the Scottish Borders where he was the life of the party both nights.

        If you are interested, his funeral will be held at Morton Hall Crematorium, Edinburgh, next Friday at 12 noon. A wake will then be held in the Cockburn Museum here in the Geology department in Edinburgh.

        Also, it is of no surprise that he had a lot of books, most of which the family have asked me to find good homes for. If you are interested, I can email you a list of his books and you make take what you like. I can arrange postage if you are not close to Edinburgh.

        Best wishes

        D

      • Hi Darren

        Barring disasters we will try to attend the funeral and the wake.

        I would be very interested in books, I still have an interest in proper Geology – I can offer a good home.

        Regards

        Barry
        Dr Barry Young | Operations Technical Support Engineer
        Baker Hughes | Operations/UK/MWD
        Office : +44 1224 359535
        Mobile: +44 7808 976 279 | barry.young@bakerhughes.com
        http://www.bakerhughes.com | Advancing Reservoir Performance

      • Barry,

        It’s lovely to hear that you will try and make it to the funeral. Please make use of me if you would like any help organising your stay here. My contact details are: d.j.wilkinson@ed.ac.uk and mobile is 07974125926. Please do get in touch.

        I’m away with my wife this weekend, but when I’m back home I’ll send you the list of books and you can arrange with me collection of those you wish to have.

        Best

        Darren

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s