411 



plete dams to water. At the north-western edge of the subterranean 

 excavation the fault was stripi)ed5 and the materials of which it is 

 composed having thinned out, the limestone was found in contact with 

 a bed of coal, the edges of which appeared bent, both the coal and 

 the limestone having a slickensides polish. By boring through the 

 limestone a second calcareous stratum was found, thus completing the 

 proofs of identity between this underground mass and that which rises 

 to the surface in the hills of Dudley Castle and the Wren's Nest. 



In the northern or Wolverhampton field, where the whole of the 

 coal measures, even to beneath the lowest beds of ironstone, (the blue 

 Jlats,) are traversed by shafts not exceeding 120 yards in depth, the 

 field has been proved at several points to rest on shale and impure 

 limestone, the equivalents of the Ludlow and Wenlock formations. 

 For lists of the fossils in this group of Upper Silurian rocks the author 

 refers to previous memoirs, announcing that more perfect lists will 

 shortly be laid before the public in his large work upon the Silurian 

 system. 



3. Lickey Quartz rock, Caradoc sandstone, (Lower Silurian rocks.) 

 Dr. Buckland first called the attention of geologists to the Lickey 

 quartz rock* ; and, showing that it had been one of the principal ma- 

 gazines of the quartz pebbles in the new red sandstone and diluvium 

 of the southern counties, he further compared it with certain rocks i« 

 situ in the neighbourhood of the Wrekin, The Rev. J, Yates has 

 also clearly described the lithological structure of this rock, and has 

 briefly touched upon some of its fossils f- Mr. Murchison undertakes to 

 prove the true geological position of these rocks. He shows that they 

 lie in the direct prolongation of the Silurian rocks of Dudley, and that, 

 being partially flanked and covered by thin patches of coal, they 

 emerge through a surrounding area of the lower new red sandstone 

 and calcareous red conglomerate (described in previous memoirs). 

 Unlike, however, the succession in the Dudley field, there are here 

 no traces of the Ludlow rock and Aymestrey limestone. Nor are 

 there masses of any size of the Wenlock limestone, but shreds only 

 of the shale or lower part of this formation with some of its well- 

 recognised fossils, {Colmers.) 



The lower Silurian rocks rise from beneath the Wenlock shale in 

 thin courses of bastard limestone, alternating with red and green 

 courses of sandstone and shale, the equivalents of those bands, which 

 at various places in Shropshire, and at Woolhope in Herefordshire, con- 

 stitute the top of the formation of Caradoc sandstones. Like these, they 

 are here underlaid by flaglike sandstones, sometimes rather more ar- 

 gillaceous and approaching to clay slate, the whole passing down into 

 silicious sandstones, both thick and thin bedded. In the latter are 

 casts of several fossils of the Caradoc formation, such as Pentameri of 

 two species, and corals peculiar to it. These fossilliferous strata are 

 well exposed on the eastern side of the hills by recen^ cuttings, where 

 the new road from Bromsgrove to Birmingham traverses the ridge. 

 The ridge itself, however, consists essentially of quartz rock, which 



* Transactions Geol. Soc, 1st Series, vol. v. p. 50/. 

 t Transactions Geol. Soc, 2nd Series, vol. ii. p. 137- 



