A HISTORY OF WORCESTERSHIRE Pendock), of Dr. C. Callaway, Mr. F. Rutley, and Prof. T. T. Groom* have most largely added to our knowledge. The most ancient rocks of Malvern are those which form the main ridge and consist of hornblendic gneiss, with numerous dykes of diorite. So long ago as 1865 Dr. Holl suggested that the crystalline schists and gneiss which had before been regarded as altered Cambrian rocks, were of Pre-Cambrian age, while shortly afterwards the Rev. J. H. Timins showed by chemical analyses that the rocks could not have resulted from the metamorphosis of any known Cambrian rocks. These views are now generally accepted. These ' Malvernian ' rocks form the nucleus of the Malvern and Abberley range and they are faulted against or over- lain unconformably by Cambrian, and again by Silurian rocks. The whole group was subsequently bent into an anticline, which is faulted on the east against the New Red rocks. Westwards the successive beds of Silurian strata dip beneath the Old Red Sandstone of Herefordshire. In 1880 Dr. Charles Callaway recognized on the eastern side of the Herefordshire Beacon certain compact felspathic and brecciated rocks, evidently of volcanic origin, and similar to those named ' Uriconian ' in the Wrekin area. These, although newer than the Malvern gneiss, are of very great antiquity. This volcanic series, as observed by Prof. Groom, consists of rhyolites, andesites, basalts and tuffs, while the bedding has a prevailing easterly dip. The junction with the Malvernian is nowhere actually exposed, and at present it is 'impossible to determine whether this junction is a fault or a surface upon which the Uriconian series was originally deposited.' ^ Prof Lapworth has observed that the best localities for studying the essential characters of the Malvern rocks are the quarries of the North Hill and the Wych, and the eastern slopes of the hills between Malvern Wells and the Herefordshire Beacon.* The Archcean rocks thus consist to a large extent of crystalline schists, for the most part highly altered or metamorphosed igneous materials, whose precise method of formation cannot be told, at any rate at present. Be- longing to the same Pre-Cambrian period there are also beds of volcanic grit and shale, and in some parts of Britain sandstones not unlike Old Red Sandstone. None but obscure traces of organic remains have been found in any of these rocks, and then but rarely ; nor are they to be expected. In the region with which we have now to deal, and in most other localities, the rocks have undergone such pressure-metamorphism that the materials of which they were originally composed have crystallized afresh. More- over, the schistose structure produced by mechanical movements, the twistings and foldings, the faults and thrust-planes, would tend to obliterate any evidences of organic structure. In some cases the rocks have been penetrated by intrusive igneous rocks prior to the latest great earth-
- Quart. Journ. Geol. Soc, vol. Iv. p. 129, and vol. Ivi. p. 138. (References to other
workers are given in these papers.)
- Ib'id.^ vol. Ivi. p. 140.
^ Article 'Geology' in Handbook of Birmingham (Brit. Assoc.) 1886, p. 222. 4
