The Disturbed Strata on the Fox Earth Coal and its Equivalents in the East Pennine Coal-Field

Publisher Website
Google Scholar
Abstract
Summary: During the course of outcrop-coal working occurrences of disturbed strata were noticed at Swallow Nest, near Sheffield. These were in the roof strata of the Fox Earth Coal, which is in the Lower similis-pulchra Zone of the Middle Coal Measures. The relations of the disturbed strata showed that they owed their structures to contemporaneous phenomena and that the disturbances were completed before the deposition of the next coal seam 32 feet higher in the sequence. The strata are cut by numerous thrusts and are contorted, folded and broken in a complex manner. The mudstones have been converted into a typical " clod ", i.e. a relatively finegrained rock which breaks continuously into small pieces and is very difficult to support in either a cliff face or underground. The underlying Fox Earth Coal is almost undisturbed. Various lines of argument led to the suggestion that the structures of these strata were due to earthquake disturbance rather than to slumping as usually understood. By reason of the detailed knowledge of the stratigraphy of the Middle Coal Measures of the East Pennine Coalfield it was possible to demonstrate that disturbed strata occur at several other localities on this horizon through the length of the coalfield. At two localities sandstone dykes cut through the underlying coal. The widespread occurrence of these phenomena at exactly the same horizon supports the suggestion that they are due to earthquake disturbance.

This publication has 15 references indexed in Scilit: