Midlands Microcraton

The Midlands Microcraton is a triangular block of late Neoproterozoic crust of igneous and volcaniclastic origin which underlies the English Midlands. Its northern tip is at the southern edge of the English Peak District and its other two corners are in the vicinity of London and Swansea. Though its northeastern edge is obscured by Palaeozoic and Mesozoic strata, the northwestern edge of the microcraton is clearly defined by the Welsh Borderland Fault System. To the south it is bounded by the Variscan Orogen.^[1][2]

References

1. Carney, J. N., et al., 2008 ⁴⁰Ar–³⁹Ar isotope constraints on the age of deformation in Charnwood Forest, UK, Geol. Mag. 145 (5), 2008, pp. 702–713
2. British Geological Survey 1996 Tectonic map of Britain, Ireland and adjacent areas Pharaoh, T.C. et al 1:1,500,000 (Keyworth, Nottingham: BGS)