These, my friends, are glacial erratics.
What?
Glacial erratics are boulders that differ from the local lithology, and that have been deposited by glacial activity. Why is this relevant? This photo was taken on Bournville Lane, just up the road from the Railway Station, opposite part of the Cadbury factory. The railway bridge is down the road to the left.
These boulders were transported by the glaciers of the last age, and it is thought they are from the Arenig region of Wales. The boulders were dumped all over South Brum as the ice melted and retreated. The boulder in the pound in Old Northfield is also a glacial erratic, and there are others dotted around.
The geo-geek inside of me is very happy about this ;)
L x
There are 2 in West Park in Wolverhampton, I'm born and bred in B17 but moved to Wolves, was great to see them there too. Wonder how many still remain across the West Midlands?
ReplyDeleteI also wonder this - I'd like to track them all down! I've also been wondering how one would go about securing funding to take samples and anaylse them and try and determine their source..
ReplyDeleteI know of a few more local to me - there is one in the pound in Old Northfield village, a couple in Cotteridge Park, and I think one at King's Norton railway station. There used to be another in Cannon Hill park but no one is sure if it's still there!
I grew up in Cannock and we had our own on Cannock Chase just known as Glacial Boulder. Quite an interesting geological area Cannock Chase.
ReplyDeleteQuite a complex area! Lots of mudstone, sandstone and siltsone, as well as conglomerates and coal measures! And then there is glacial till and river gravel deposits - must visit it properly one day with my geology head on.
ReplyDeleteScreengrab from Google Earth for reference - http://i49.tinypic.com/35jghn8.png - Pink is sandstone & conglomerate; Green is siltstone, sandstone & mudstone; red is mudstone, siltstone and sandstone from a different age and the blue is a hodgepodge of allsorts! Mudstone, siltstone, sandstone, coal, ironstone and ferricrete!
I'd still like to know exactly where the boulders came from for certain - the ice came down quite a long way so could be from anywhere!
Would you recommend cleaning these ancient boulders? Not a good idea removing all that biodiversity in the form of mosses and lichens. Stupid and selfish people.
ReplyDelete