Severn Vale Geology
The Geology of the Severn Vale is simpler than either the Forest of Dean and the Cotswolds in general terms, but does have its complexities when looked at in detail. The oldest rocks to the east of the boundary fault that separates the Vale from the Dean are those mudstones and sandstones belonging to the Triassic age Mercia Mudstone Group.
These are overlain by the Penarth Group, representing a transition between terrestrial and marine deposits and forms the junction between the Triassic and Jurassic strata. Within the Penarth Group is an important bed containing fossilised fish, reptile and dinosaur bone. Above this lies the Lias Group of the Lower Jurassic that hails the onset of a prolonged period of deposition of marine sediments that lasts right up until the end of the Jurassic Period (see Cotswolds Geology).
Geology and Landscpe Guides in the Severn Vale