THE BOOK
Some of the ideas discussed in this blog are published in my book called "The Bluestone Enigma" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
To order, click
HERE

Friday, 21 October 2016

Erratic behaviour in the Midlands


 Pic:  Valerie Kedge

Strange goings-on in the Midlands these days.  Suddenly, they seem to have discovered that glacial erratics are rather interesting.  Better late than never.  Once upon a time, before people started messing about with the landscape and built Birmingham and its suburbs, there were vast expanses of glacial and fluvioglacial deposits (and some pro-glacial lake deposits too) in the south Midlands, with some clearly delineated landforms including terraces in river valleys, and thousands of glacial erratics scattered across the landscape.  As in other glaciated areas, most of these erratics were cleared away over thousands of years of land clearance, leaving just a residue of the larger ones that nobody could be bothered to move.  I suppose that some were incorporated into dolmens and round barrows, and some (if they had convenient pillar-like shapes) would have been put up as standing stones too.

There is plenty in the literature about these Midlands erratics, including protracted discussions about ice movement directions and provenances.  Many of the old geologists were good at rough provenancing, although of course their identifications of sources and the names used for rock types have changed over time.

This brings us to the recent fun and games relating to one particular erratic boulder at Northfield in the southern suburbs of Birmingham.  Somebody decided it would be a good idea to flag up its importance and to stick up a plaque in its honour.  It's called "The Great Stone" and it is currently located within the village pound.  Next door is the Great Stone Inn, so no doubt the stony attraction will bring in a bit of extra trade.........

It appears that there was an interest in the probable provenance of the stone, which was assumed to have come from the Arenig volcanic sequence around Snowdon in North Wales.  A sample of the rock was sent to Rob Ixer, and he confirmed the provenance, and in exchange for his hard work he was invited to unveil the magnificent new plaque at a grand civic ceremony earlier this month.

See this:
http://earthwise.bgs.ac.uk/index.php/Arenig_Series,_Ordovician,_Wales

The media coverage of this magnificent event is so garbled and nonsensical that we had best stay well clear of it, for fear of causing embarrassment........

You can find out more about the Birmingham erratics (mostly reliable info) here:
http://geologymatters.org.uk/2012/02/16/erratic-ice-of-the-black-country/
bcgs.info/pub/wp-content/uploads/newsletters/BCGS_Newsletter207.pdf
bcgs.info/pub/wp-content/uploads/newsletters/BCGS_Newsletter206.pdf 
http://brummiesguidetobirmingham.blogspot.co.uk/2012/07/glacial-erratics-in-bournville.html 
http://brummiesguidetobirmingham.blogspot.co.uk/2013/02/glacial-erratic-university-of-birmingham.html

This is more or less what I sent to Rob, when he asked what the context might be:  In terms of its Quaternary history, the Birmingham area is completely chaotic -- it seems that Devensian ice did not reach south Birmingham, but Anglian ice certainly did.  And some people think there was a third glaciation -- the Wolstonian -- that reached the area too -- but the evidence is hard to interpret.  There have been glacial lakes too -- to add to the confusion.  My best guess is that Snowdon erratics got into the area at some stage in the Anglian -- but towards the peak of that glaciation the most powerful ice stream came in over the Cheshire Plain -- it's called the Eastern Irish Sea Ice Stream.  Snowdon erratics could therefore have been moved several times -- following a somewhat erratic course.  You could also get erratics in that area from the Irish Sea Basin (including Scotland) and also from northern England, because Pennine ice was also coming south across the area at some stage.  That all adds up to an extraordinary mishmash of erratics from all over the place. 

 One interesting sidelight on all of this relates to the Stonehenge Altar Stone.  It will be recalled that it sits rather uneasily with the assortment of other bluestones at Stonehenge, which have come from north Pembrokeshire.  I have argued earlier that the route followed to the Altar Stone probably involved initial carriage by Welsh Ice from a source area in the Brecon Beacons or in one of the South Wales Valleys, and then carriage by a part of the Irish Sea ice stream towards its final resting place.  As in the case of the Great Stone at Northfield, we are talking about the Anglian Glaciation, around 500,000 years ago.  Another erratic route for an erratic boulder.........





 

13 comments:

TonyH said...

Well, we now clearly have an excellent candidate for official collective noun for erratics, courtesy of Dr John.

'A Mishmash of Erratics'!! I'm sure Suzy Dent [of Countdown and more notable provenances] would approve this collective noun. Mishmash even sounds as if it may have as interesting an origin as the provenances of many erratics.

And we all approve of Suzy Dent, particularly on her subversive antedote programme, "Eight Out of Ten Cats Do Countdown" (Saturday nights, Cats, Be There or be Square!).

Also, she has a new book out, just in time for Christmas which, alarmingly, Myris of West Midlands Suburbia is reviewing as I type. By the way, thought he was looking rather similar in the photo to that other National Treasure from the West Midlands, Prof Mick
Aston [RIP].

T said...

I have just heard, on good Authority, that Dudley's Own Lenny Henry is to unveil an Erratic outside that West Midlands town's Premier Inn, which he insists arrived from Jamaica long before his own parents.

[N.B. this was a NON = RACIST joke .............. on the contrary, entirely Geographically - based. Give Lenny a Knighthood if he hasn't got one already].

By the way, contrary to what Dr John says in his attached piece, I think it's GREAT that so many of our Trading Estates and Industrial Estates and Roundabouts have allowed the Erratics to REMAIN for all to see, not just in the West Midlands but all over this great, Geomorphologically - affected Country of ours!

MoA said...

Suzy Dent sibling of Arthur?

An avatar of Mick Aston, sadly this has been asked often, Dr Ixer always says he is Mike Aston and then runs off with the family silver.

It is the standard dress of top notch archaeologists/field geologists or it could be that 107 people were more than the dozen or so and highly informal do that Dr Ixer expected. His wife did warn him and ask that he changed into something a bit more formal as he left his front door but ---you know the rest.

The work is 'on-going' with other nearby erratics also being sectioned (along with...). I should be so lucky

M

BRIAN JOHN said...

Ah yes -- as MPP is always happy to demonstrate, it's always good to be under-dressed for any occasion...... rugged sweaty fieldworker just out of the latest excavation pit, and all that sort of stuff. Believe it if you like.

Neil Wiseman said...

Great picture, Brian!

I see our Vagabond Geologist is well represented — though perhaps he merely wandered into the shot on his stroll to the local biscuit giveaway ...

Neil

BRIAN JOHN said...

Not my picture, Neil. Kindly provided by our vagabond geologist...........

MoA said...

Original photo is by Mrs Valerie Kedge married to Roland who was the instigator of all this.

Sadly not a single biscuit was in evidence but a free cup of that 'that refreshes but does not inebriate' and after a whip round, a couple of boutique beers.

VG last seen lurching towards north Brum, muttering "do you know who ...."
M

BRIAN JOHN said...

Yes, those guided footpath trails look like a great idea -- all success to them! And if the hearty walkers call by a few pubs, and appreciate a few erratics, on route, they will be that much closer to a state of enlightenment.......

TonyH said...

Looks like our Vagabond Geologist is just about to unveil, from behind those luscious velvet curtains, a Show: perhaps a Punch & Judy Show?......

.......Does anyone follow my (glacial) drift?!

TonyH said...

We have a village pound near us, too, at North Bradley, only about 4 miles from the Salisbury Plain escarpment and the well - known Westbury White Horse. So we have a ready - made slot for the bluestone erratic that will inevitably turn up sooner or later not too far away. It may - who knows? - be sitting there, waiting for its recovery, a la Boles Barrow bluestone, BENEATH one end or other of the Long Barrow, visible from North Bradley, above that same White Horse.

MoA said...

Note Dr I is available and highly experienced at unveiling. Good quality biscuits are required. No rich tea. Bourbons, rather than their nemesis, Garibaldis.
Talking of royalty. Those lovely curtains ""have been used by royalty"" (as Dr I was informed by the Brum Civic Soc during the (un)dress rehearsal.

The only Punch and Judy show is here. That's the way to do it'.
M

TonyH said...

What about those legendary senior archaeologist Brothers Grimm for Punch & Judy double - acts??

One of those Bros currently performs in front of geriatrics on the early November beaches, I hear, somewhere on the South coast......

TonyH said...

Yes, we are able to provide a good selection of Dr Ixer's favourite biscuits [at the adjacent Peace Memorial Hall, North Bradley]. Incidentally, he will also be able to view the assembly of rather dodgy - looking Erratics brought in, undoubtedly, by HUMAN means to the nearby White Horse Business Park.