Lava - water interactions

The Honister slate mines in the Lake district are rightly famous as for centuries, the finely laminated Ordovician slates have provide a time honoured roofing material, and in more recent years, they have provided trinkets for the tourists at the visitor centre.  The exceptional beauty of the slate has also seen it used as a municipal decorative stone - visit St Nics shopping arcade in nearby Lancaster - you'll see some there.  The slates are the remains of ancient ash fall deposits, squashed, metamorphosed and then exhumed by the weather and the years.

The original fall deposition features can often be seen on this commemorative plaque a few hundred yards from the visitor centre.  There is clear evidence from different grain sizes and textures and things like graded bedding that there is more than one eruptive episode represented - the course to fine  upward grading indicates a degree of gravitational settling, possibly in still or only weakly flowing water. The evidence for water is also there further up the path were it is lined by large jagged boulder size chunks of a rock called Peperite.

Peperite at Honister slate Mine

Large jagged chucks of often vesicular Andesite are nested in the blue grey remains of what was once wet layered ash/mud at the bottom of a lake.  The Andesite intruded into the wet mud with the inevitable reaction. In the open air, with the lack of confining pressure, the lava acts in a phreatomagmatic manner - explosively, producing a fine ash.  Confined by water and heavy wet mud, the lava fractured on a much larger scale.

Cartoon of Peperite formation

Beyond the old miners cottages, across a bubbling mountain stream, the hills to the south offer evidence of the explosive nature of the andesite eruptions with fall and gravity flow deposits.  Bomb sags are a frequent occurrence, as are quasi-sedimentary structures like cross-bedding.  The different sizes of clast form distinct gravity driven layers which have now been heavily faulted. 

Bomb sag in a fall deposit

Airborne fall deposits and later faulting.

Miners Cottage - Honister Pass

So Where have I been?

Did I mention that I was going to Lancaster University to study Volcanoes.  Now I know what you're thinking.  There aint a heap of volcanoes in the UK, much less Lancaster.  But that's where you're wrong.  OK so they are not going BANG any more, but they're there none the less - or should I say the rocks they produced are there.  It's easy to dismiss this countries volcanic heritage, but for those in the know, little pockets of evidence pop up all over the place of what an exciting place the UK once was to live in.  Traveler Sir Joseph Banks and composer Felix Mendelssohn both in their own ways extolled the beauty and virtues of the Scottish Island of Staffa - a name of Nordic derivation meaning Pillar Island - a reference to the famous columnar lava flows at Fingals cave.  Hadrians Wall perches for many a mile atop an igneous intrusion, part of a network of similar intrusions that stretch from the island of Mull to the Northumberland coast where Bamborough dominates its surrounding from the summit of another intrusion.  A few miles out to sea the Farne islands, a bird watchers paradise are also of interest to the volcanologist, while across the Pennines, the Lake District is studded with volcanic deposits and evidence of its violent past.

Further south, the carboniferous limestone of Cavedale near Castleton in the in the Peak District is crossed by an equally carboniferous basalt lava flow, and the summit rocks of Beacon Hill in Leicestershire were formed from explosive volcanic ash fall in a time when only single celled organisms inhabited the Earth.  Igneous deposits and rocks also pop up in Wales and the south west of England being responsible for both  the famous mineral resources and rolling moorland of that area. So yes Britain has plenty to offer the Volcanologist.  

Lancaster has one of the largest and foremost outposts of volcanologists and I spent a year with them studying a M.Sc in Volcanology and enabling me to build on my knowledge and skills from the B.Sc I studied with the Open Uni and make some valuable contacts in the process.  Anyone interested in Volcanoes should go there and watch Dr Hugh Tuffen cook rocks.  But there's more to it than that - It's a community of the like minded from world leading researchers to young hopefuls like me taking their first faltering steps into researching volcanoes, 

It is a shame that the university has ditched its famous Lancaster University Swoosh logo in favour of something more Heraldic (the Robot - go to the website and check it out).  It may be that bit more dignified and that bit less like the Atari logo, but what the heck, can you do this with the robot?

I think Not.


And Oh boy what a first step into research!  I could have done one of the Lancaster University recommended dissertation subjects, but I wanted something that was completely my own.  Now, we all know that there's nothing new under the sun, but I was persistent in my ideas of what I wanted to do and in combination with academic Dr Mike James an idea for an original body of research gradually crystallized (Ha Ha, no pun intended), and with both Mike and Hugh on-board as supervisors, I had the best educational experience of my life, bar none.  This is what being on the sharp end of something is all about.  Anyway, More about that later.  Suffice to say that I have had the time of my life becoming a Master of Science, Rock Master, Volcanoman, whatever, and there are only more adventures to come!  Watch this space.