TRANSACTIONS OP THE SECTIONS. 51 



clinal is traceable from uenr the exposure of the igneous rock at Uphill, along 

 Bleadon Hill, thence under the New Ked Sandstone to Padiugham, and Dolomitic 

 Conglomerate and Calamine beds of Shipham, through the Old Red Sandstone of 

 Blackdown, and on through the Carboniferous Limestone of Lamb-bottom, where 

 it is lost under the cherty Khtetic beds of Harptree Hill. From Little Elm on the 

 extreme east to Masbury Castle nearly due west of the range, the Old Red is again 

 exposed for three miles, which is likewise due to the anticlinal axis. 



At Masbury Castle we lose trace of tliis S.E. anticlinal, and a second .and parallel 

 cue to that of Blackdown occm-s, ranging from the Old lied of North Hill through 

 the Carboniferous Limestone of Stoke Warren, and last under the dolomitic conglo- 

 merate of North Draycott. This may j oin the great anticlinal near Egar Hill. We 

 thus see that the strike of the Mendipswas induced by a force which has brought out 

 its oldest rock to the surface, and thereby produced the present physiogi-aphy of the 

 bold range of hills we are now considering. 



Carhoniferous Limestone surrounds the exposed and concealed nucleus of Old Red, 

 and is conformable therewith both in dip and strike. The Carboniferous Limestone 

 has gi-and development in the Mendips, and constitutes the gi-eat mass of the chain, 

 having a continuous spread of five miles between Westbury Beacon and Abley, also 

 between Crosconibe and Eniben-ow. The Lower Limestone shales are .nowliere 

 more finely exposed than around and resting on the upper members of the Old Red 

 Sandstone, and are highly fossiliferous throughout, the beds being crowded with 

 Strojyliomena, Chonetes, Spinfei-a, Polyzoa, the ossicula of Crinoids, and many Tri- 

 lobites, presenting a strong contrast to the barren beds of the Old Red on which they 

 conformably rest. The Shales are well developed around Blackdown, especially to 

 the east of Charterhouse, at Rowbarrow and Priddy, west of North HiU, and Nine 

 Barrows ; and east of Egar Hill tliey attain a thickness of 500 feet, and are extremely 

 rich in organic remains. They present an extended outcrop from Masbury to Stoke 

 Lane, and Leigh upon Mendip, and in the Downhead beds near Asham Woods. 

 The local development of these argillaceous beds of the lowest division of the Car- 

 boniferous Limestone first gave origin to the name Lower Limestone Shales. They 

 are almost special to the west of England, and are exposed on both flanks of the 

 Mendip range. On them rest the thick-bedded strata of the Carboniferous Lime- 

 stone, which is everywhere traceable for thirty miles from Oldford, the gorge of the 

 Vallis to Elm on the east, to the distant headland of Bleadon in the west, and 

 everywhere abounding more or less with organisms which form the leading fossils 

 in its beds. 



Coal Measures. — On the northern flank of the Mendips, between Binegar and 

 Wells, and resting on the Millstone Grit, highly faxdted and contorted, are the well- 

 known Coals of Vobster, Holcombe, Pitcot, &c., that portion on the west at Stratton 

 on the Fosse, Downside, &c. being covered by Dolomitic Conglomerate, the eastern 

 side at Newbury and Vobster being overlain by the same rock and the Inferior 

 Oolite. There is no reason why we should not conclude that the Coals of the 

 northern side once extended across the Mendips and now lie deeply buried along the 

 south parts of the range. At Ebber rocks, west of Wells, we have evidence of the 

 Millstone Grit resting on the Carboniferous Limestone ; and the elevation of the 

 Mendips being post-Carboniferous, lends an additional reason for the occurrence of 

 the Coals of the northern area to the south of the Mendips, and beneath the Lias 

 and Peat plain of Glastonbury, Castle Carey, the Pennards, and the Poldon Hills. 

 No Coal area in the United Kingdom is so disturbed and folded both along its strike 

 and on the dip of tlie Coals as those of North Mendips ; and like the Coals of the 

 " Mons Coal-field" in Belgium, which exists under similar conditions, the seams are 

 vertical and thrown over, so that the same seams are passed through by shafts two or 

 three times. The Vobster and Holcombe Coal-seams are the same as those at Ashton 

 and Kingswood near Bristol, Twerton near Bath, and probably the same as those at 

 Yate. They underlie the whole area between the IMendips and'Bristol, and are proba- 

 bly the sanie that occur at Iun<?swood and underlie the Pennant at Coal-pit Heath. 



27(6 Trias. — Two divisions of this group are greatly developed around and upon 

 the Mendips, especially the inferior or Dolomitic Conglomerate, a peculiar and local 

 condition of the base of the Keuper Sandstone of the Bristol and South Wales 

 Coal-fields, chiefly that portion of the latter which attends from Cardifl:' to Bridg. 



