ON EXCAVATIONS IN THE PALAEOZOIC ROCKS OF WALES, &C. 231 



The Excavcdion of Critical Sections in the Palceozoio RocJcs of Wales 

 and the West of England. — Report of the Gommittfre, consisting of 

 Professor C. Lapworth (Chairman), Mr. CI. W. Fearnsides 

 (Secretary), Mr. J. Lomas, Dr. J. E. Marr, Professor W. W. 

 Watts, arid Mr. G. W, Williams. 



On some Excavations in the Cambrian Rocks of Comleij, Shropslbire, 1907. 



By E. S. CoBBOLD, F.G.S. 



The locality of Coiuley has long been classical in geology as the only 

 place in Shropshire where Lower, Middle, and (so-called) Upper Cambrian 

 rocks, occurring in juxtaposition, are all known to yield fossils. 



The chief point of interest has been the little Quarry of Comley, in 

 which both the characteristic genera of Trilobites of the Lower and 

 Middle divisions of the Cambrian system — namely, Olenellus and Para- 

 doxides — occur in close association. 



These rocks of the Comley district were first claimed as Cambrian by 

 Dr. Chas Callaway ' in 1878, and paralleled by him with the Hollybush 

 sandstone of the Malvern district. 



In 1888 Professor Lapworth announced ^ the discovery of an Olenellus 

 [0. Callavei, Lapw.) from the band of purplish-red calcareous sand- 

 stone of the Comley Quarry, which band has become generally known 

 among English geologists as the Olenellus Limestone band of Comley, 

 or, locally, the Olenellus Limestone. 



In 1891 Lapworth described and figured the Olenellus,^ and at the 

 same time announced his discovery of a Paradoxides (which he named 

 P. Groomii) from the conglomerates and limestones overlying the 

 Olenellus Limestone in the same quarry. 



Although it was thus well known that both Lower and Middle 

 Cambrian rocks were present in the locality, the line between them had 

 not hitherto been exactly determined. 



The Cambrian formations of the Comley area hitherto recognised are 

 as follows : — 



III. Uirper Cambrian Shales, so called (the Shineton Shales of 

 Callaway, op. cit.). 



II. The Comley Sandstone of Lapworth, op. cit., divisible into a 

 lower and an upper portion, the latter representing parts of the Middle 

 Cambrian, and the former parts of the Lower Cambrian of other regions. 



I. The Wrekin Quartzite of Callaway at the base. 



The excavations described in this report have been confined to the 

 Comley Sandstone Series above mentioned. 



The geology of the Comley area presents considerable difficulties 

 owing to the obscure and faulted nature of the ground. It will be seen 

 from the, accompanying sketch-map that the main mass of the area 

 under description is occupied by the Comley Sandstone Series. This 

 is underlain to the west by the Wrekin Quartzite, but the only fairly 



• Callaway, Quart. Jour. Geol. Soc, vol. xxxiv. 1878, p. 759. 



* Lapworth, Geol. Jfiiff., December 3, vol. v. 1888, p. 484, 

 » ibid., vol. viii. 1891, p. 539. 



