Geo-Amble 7th August

We met at the Talbot, Knightwick, had a look at the large stone apple press, (HERE for Building Stones database information) its quartz conglomerate wheel, past the now converted church (HERE) with its varieties of building stones then tackled the steep road to join the Worcestershire Way going North.  En-route lying on the grassy verge to stop cars parking, we discovered a triplet of foreigners, rocks that definitely do not come from this neck of the woods (see pics).  Later investigation was conclusive in that the two obviously igneous rocks were granites from Shap in NW England and the black rock with quartz vein seems to be Greywacke, probably from Scotland, a very mixed, sedimentary rock formed by underwater turbidity currents (the third picture on the above web page is very similar to the rock we saw by the roadside in Knightwick in my opinion).  Thanks to Prof. Donny Hutton and Moira Jenkins for the detective work. Moira showed us a beautiful polished piece of Shap granite that she has on a shelf at home.

Cross the road, watch the traffic, carry on up the Worcestershire Way, through the dense, mixed woodland that now cloaks the hills.  Closer examination and explorative walks show a hillside pock marked all over with the remains of old quarries and of long-left buildings.  There must be a fascinating social history waiting to be discovered.

According to the geological map, along the road and at the top of the hill, we were in Wyche Formation, Silurian, no lime content (verified with acid afterwards), fine silt and sandstones (Sandstone, Micaceous. Sedimentary Bedrock formed approximately 428 to 436 million years ago in the Silurian Period. Local environment previously dominated by shallow seas. Generally grey, brown and pale green mudstones and siltstones with thin tabular green sandstones. Setting: shallow seas. These rocks were formed in shallow seas with mainly siliciclastic sediments (comprising of fragments or clasts of silicate minerals) deposited as mud, silt, sand and gravel).

Wyche Formation from Top of Ankerdine

Wyche Formation from Top of Ankerdine

The Wyche is older than the more familiar Much Wenlock limestone of the area, which according to the map, we traversed on our way uphill.  One can only presume that the limestones were used for rubble building and for lime burning to put on fields or to make lime mortar, as happened all along this ridge.  On the other hand the Wyche is quite blocky in nature, see pics, and probably lends itself quite well to more regular building.  At any rate at the top of the hill, yards before the East Malvern Fault completely transforms the geological content, lie the remains of quarries, with old entrance ways, ancient yew trees and some small exposures.  In short order, a group could easily make this more visible and accessible but doubt the County Council would appreciate that as it is one of their managed areas and previous proposals of ours have been dismissed, well, dismissively.

From there we strolled along the Worc. Way to the picnic and car park areas where a board explained something about the Common. Good views over towards Bromyard and its plateau of Devonian St Maughans. In not too unseemly haste we tripped downhill into the comfort of the Talbot’s lounge and the health giving properties of its home brewed ales.  Very pleasant.

HERE is a geological map of the area followed below the evening’s pictures.

During the week I have come across two topics worth noting.  The first is a critique of Tolkien’s map of Middle Earth from Lord of the Rings (map).  The second is a fascinating article on minerals that have yet to be discovered (+-5000 known +-1500 to go)  HERE