Scottish gold!

Last week, I drove a Land Rover up to Tyndrum to collect a large sculptural block of rock for the Hunterian's forthcoming Scottish Gold exhibtion. Chris Sangster, the Scotgold CEO kindly accompanied us, and we were able to drive right up to the Cononish mine along the access track.

Although the mine is currently being developed, the mine dumps are mostly the result of development work carried out by Ennex in the 1980s, and it's amazing how quickly the rock surfaces are becoming colonized by mosses and lichens. However, we managed to find a nice large block of rock cut by abundant quartz veins:

Having the vehicle beside the dump makes collecting such large blocks easy!

Afterwards, Chris the designer, and Neil the photographer spent a long time standing in the river with a fancy camera on a tripod, capturing the essence of the gold-rich landscape.

Blockbuster exhibition opens on 14th March!

The Brighton Medal

Yesterday, a medal arrived in the post.

In early December 2013, a week or so before the AGM of the Geological Curators Group,  I'd received a  phone call from Mike Howe, who was just finishing his term as Chair of the GCG committee. I'd been nominated for the Brighton Medal, probably the only award for geological curators anywhere in the world. I was not having a good day, and feeling stressed and a bit isolated, so this was astoundingly nice news from the outside world. I was gobsmacked.

Unfortunately, I was unable to attend the meeting in Canterbury at which the award was to be made. I proposed a high-tech virtual presence via Skype - I would make an acceptance speech from a laptop screen. Having had the agenda for the meeting, I waited by my computer and phone. And waited. And waited.

Somewhere between Canterbury and Glasgow things had gone wrong.  The award was made, but I was unable to say "thank you" at the time. Now it's arrived - and I'm very grateful and honoured.

You can read Mike's citation for the award here. 

This is the first medal I've had since the Duke of Edinburgh's Bronze Award (some time ago!), and the first unsolicited one I've ever received. It's extremely encouraging to feel appreciated by others, and I'm very grateful (and suprised) that my work has been conisdered of significance. Looking at the other recipients, inlcuding my mentor at the University of Leicester, Roy Clements, two feelings arise: firstly, can I really deserve this? And secondly, I must be getting old, if my career is long enough to honour. Anyway, I'm very grateful

 

The Brighton Medal was inaugurated in 1992, and named after the pioneering curator Bertie Brighton, of the Sedgewick Museum at the University of Cambridge. It is awarded "for outstanding service to the service of geology in museums", and struck in silver. The award is made every two or three years, whenever the chairperson of GCG stands down from the committee. I was the 10th recipient, and got the last of the original batch of medals, struck by the Tower Mint, in London in 1992.

Loveliest rocks displayed at VMSG 2014

My favourite rock images from the posters presented at the 2014 Volcanic and Magmatic Studies Group meeting in Edinburgh:

A. Outcrops

If Carlsberg made outcrops... a mouth-watering pair of outcrops in the Leka Ophiolite, western Norway (Brian O'Driscoll)

B. Section images

A difficult choice here, so here are four good ones:

Large elongate/skeletal olivines in picrite dyke, Skye (Holly Spice)

The freshest mantle peridotites you could wish for. They've got garnet+-spinel, and come from alkali-olivine basalts of Pali Aike, in Argentina. Possibly the finest mantle xenoliths in the world? (Eve Rooks)

A terrible blurred picture of a beautful rock. These phonolitic tuffs from northern Tanzania have the most lovely zoned Na-rich clinopyroxenes. And they've got hominid footprints on the top of the ash bed. (Anna Balashova)

Not an optical microscope image, but fantastic images of great rocks. QemScan images of variolitic picrite from Rum and chrome-spinel layer in anorthosite. (Alan Butcher, FEI)

An excellent meeting, made even better by explosive duck-volcano.

Good and bad rocks

The beautiful and varied rocks of Mull have been one of the biggest influences on me. Even when very young,  I realised that not all rocks were the same. Some made lovely outcrops. Some were just one colour. Others were sparklingly varied.  Some contained interresting crystals. Best of all, some had big garnets, or even small sapphires. From an early age, I had strong views about rocks, and was accustomed to judging them on how much I liked them.

Me, aged about 9 (?) investigating beautiful Moine semi-pelites below Dun a' Gheird, east of Uisken on the south coast of Mull. Note the "hard rock" sized hammer.

Although I have been a professional geologist for nearly 30 years, I still can't help making these kind of judgments. There are individual rocks I like. And there are individual rocks I don't.

These judgements can be applied to a landscape or outcrop, or to a hand specimen, or at a microscopic scale. Ideally, a rock should be pleasing at any scale.

Some things that tend to make for a good rock:

• medium-coarse grain size
• pristine igneous or peak-metamorphic assemblages
• some glass  (but not just glass - crystals needed as well)
• inhomogeneity: drusy cavities, banding, layering, magma-mixing, immiscibility etc
• a nice ringing or musical tone when hit with a hammer
• exotic chemistry

Some things that tend to make for a bad rock:

• fine grain size
• homogeneity
• faults (except pseudotachylites, or where nicely mineralised)
• retrogression
• alteration 
• low-temperature shearing/deformation
• small-scale joints or cracks
• low mechanical strength
• mundane chemistry

Of course, this is quite illogical, unjustifiable and many of my criteria are mutually inconsistent. Low temperature equilibration of higher-temperature assemblages creates our inhabitable world. To say that chemistry is mundane, is just to say that it is common, and therefore really important. However, this is not really the point. The alteration of feldspars may be critically important to our Earth, but it doesn't usually produce nice rocks, and a little part of my brain will thus always regard it as a bad thing.  Is this just me? Does anyone prefer a weathered rock to a fresh one? (Apart from microbes).

I must look out some example images of good and bad rocks.