Out with my rock friends up on the heath at Charnwood Lodge National Nature Reserve yesterday evening.
These outcrops are created of various volcaniclastic sediments spewed from the long sleeping cores of the Charnian volcanic arc, before in later years being crushed and folded into an anticline and raised up into the "mini upland" region that survives today.
These rocks are of great geological interest as a rarely exposed view of the basement rocks that lie deep beneath younger strata.
They are the type rocks of the Charnian terrane.. a subsection of the Anglo Brabant massif... a complex of connected structures stretching across England and Wales and over to Belgian.
Together the Wrekin and Charnian terranes form the great triangle of the Midlands Microcraton....
A craton is a big chunk of crust made of a particularly solid rock which is resistant to crushing. They are like jigsaw pieces travelling around the planet, slotting themselves into place as time and tide decide.
They are normally VAST. This one is very small.
The crushing and shearing forces involved in the cratons movement into place would have been unimaginable and the hardness of its component rocks explains why the midlands are largely flat or rolling and contain no mountain zones or true uplands.
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