The Petalocrinus Limestone Horizon at Woolhope, Herefordshire

Abstract

The classic ground of the Woolhope Silurian inlier, situated some 5 miles south-east of the city of Hereford, has been described by various authors 1 ; its general dome-shaped form and the sequence of beds from Upper Llandovery to Downtonian are, therefore, well known. This communication deals in greater detail with the central area of the dome, which is occupied by the outcrops of Upper Llandovery rocks and overlying Woolhope Limestone. Murchison's description 2 of the succession of these beds at Woolhope has been tabulated by Prof. O. T. Jones, 3 in his paper on the Valentian Series, as follows:— Prof. Jones pointed out that the systematic position of the shales with calcareous flags and the overlying earthy limestones is not clear from the description given by Murchison, who apparently regarded them as passage-beds from the Upper Llandovery into the Woolhope Series. In the same paper he observed that ‘their chief interest is in the occurrence of the well-marked species Stricklandinia lirata (forma typica), which appears to be of very restricted vertical range. As there is no information in regard to the fauna associated with that species, it is impossible to decide whether the horizon should be attached to the Woolhope or to the Llandovery.’ Prof. Jones pointed out that the systematic position of the shales with calcerous flags and the overlying earthly limestones is not clear from the description given by Murchison, who apparently regarded them as passage-beds from the Upper Llandovery into the Woolhope Series. In the same paper he observed that