The Permian is everywhere covered up unconformably, or locally overlapped, by the various members of the Triassic formation; all the subdivisions of the Triassic series being found resting immediately upon it in turns as they are followed from the valley of the Severn to the neighbourhood of Charnwood Forest.
In the neighbourhood of Enville and the Forest of Wyre, three divisions are recognisable in the Permian, viz.:—
(1.) Lower Red Sandstones and Marls, with bands of calcareous conglomerate.
(2.) Coarse Breccia.
(3.) Upper Red Sandstones and Marls.
Round the South Staffordshire Coalfield the Breccia is the highest division exposed, and this only occurs in force to the south of the coalfield.
Between Tamworth and Kenilworth, to the east of Birmingham, the Permian strata floor a wide tract of country, and lie almost horizontal. Red sandstones, marls and beds of breccia occur in association, but the divisions named above are not individually recognisable.
By far the most striking local member of the Permian formation is the so-called Volcanic or Permian Breccia. It is found in scattered patches over an area of about 500 square miles, extending from the Malverns to Enville, Stourbridge, and the Lickey Hills. It is made up of angular fragments of volcanic rocks, tuffs, altered shales, grits, and slabs of fossiliferous sandstone and limestones, all embedded in paste of bright red marl or pebbly sandstone. It is usually both underlain and overlain by red sandstones and marls, but sometimes, as at Stagbury and Woodbury Hills, &c., in the Valley of the Severn, it reposes at once upon pre-Permian rock.
This peculiar Breccia is well displayed in the Clent Hills, between Hagley and Halesowen. It there reposes upon the Lower Permian Sandstones with calcareous grit bands—(which may be seen above the little Church of St. Kenelm)—and forms all the highest points of the Clent Hills, passing unconformably to the southward under the pebble beds of the New Red Sandstone. In this locality the angular fragments composing the Breccia are mainly volcanic:—rhyolites, porphyrites, ashes, and volcanic grits, embedded in a coarse matrix formed of similar materials. Other sections are seen in the Bromsgrove Lickey Hills, and in the neighbourhood of Northfield. In the last-named locality an excellent section is exposed in a lane leading from the Bell Inn to Bangham Pit. In this exposure the breccia, which shows the usual preponderance of volcanic materials, contains in addition fragments of Silurian limestone (crowded with characteristic fossils), and pieces of Landovery grit and shale.
According to Sir Andrew Ramsay,[60] this Permian breccia is probably of glacial origin, its materials having been brought down by ice in Permian times from the neighbourhood of the Longmynd in central Shropshire, where all the formations represented in its derived rock fragments occur at present in natural juxtaposition. According to Professor Jukes,[61] the fragments of the Northfield breccia, at any rate, “may have been derived from adjacent rocks, now concealed under the Permian and New Red Sandstone.”