Page:VCH Worcestershire 1.djvu/40

 A HISTORY OF WORCESTERSHIRE The Downton Sandstones are yellow and grey sandstones which are quarried in places for building purposes. They yield Lingula cornea, and also remains of fishes and Crustacea as in the Upper Ludlow rocks. From the Upper Ludlow Beds to the Old Red Sandstone the series, which includes in ascending order the Downton Sandstones and Ledbury Shales, is a transitional one, and the strata are often spoken of as ' Passage Beds.' The Ledbury Shales comprise red and mottled marls and sandy beds, as well as shales, and they were well exposed in the Ledbury tunnel on the Worcester and Hereford railway. Together with equivalent Tilestones, they were grouped by the Rev. W. S. Symonds with the Silurian, as they contain fossils which for the most part have Silurian affinities, although the fishes serve to connect them with the Old Red Sandstone. Certain gritty beds yielded Auchenaspis salteri, while from the Tilestones of Trimpley, near Bewdley, many fossils have been obtained, such as Pterygotus, Cephalaspis, Auchenaspis, etc.^ It is in- teresting to notice that the Silurian passage-beds have been proved in a boring near Halesowen.^ In Silurian times we have evidence of conditions that were entirely marine, and generally those of warm regions. We have distinct evi- dence of old coral-growths, and in the later deposits we find the earliest traces of land-plants and also of fishes. Among the newer strata also shallower water conditions prevailed ; and we pass in the Worcester- shire region gradually from marine into what are regarded as the con- tinental conditions of the Old Red period. OLD RED SANDSTONE The Old Red Sandstone, to which especial charm is attached through the writings of Hugh Miller, tells of huge lakes tenanted by curious fishes and still stranger Crustacea. The Rev. W. S. Symonds questioned whether the formation was laid down in freshwater areas, because some of the characteristic genera, both of fishes and Crustacea, occur in association with marine forms in the later Silurian strata.^ Be this as it may, the region was probably a subsiding one, as the higher beds of the Old Red Sandstone extend over a wider tract than do the lower portions. In the Worcestershire area we have, however, to deal only with the Lower Old Red Sandstone ; and it may be observed that a considerable portion of the formation is composed of red and mottled marls, resembling many beds in the Permian and Triassic or ' New Red Sandstone ' series, and that such coloured strata are usually associated with freshwater or estuarine conditions. Notwithstanding all that has been written about its organic remains, the Old Red Sandstone is not a very fossiliferous formation. Roberts, Geologist, vol. ii. p. 1 17. ^ Lapworth, Proc. Geol. Assoc, vol. xv. p. 354. ' See also E. Ray Lankester, Geol. Mag., vol. vii. p. 399.
 * Symonds, Quart. Journ. Geol. Soc, vol. xvii. p. 152 ; Murchison, Silurla ; and G. E.