Correspondence. 237 



in these parts must have proceeded obliquely to the strike. In those 

 escarpments which consist of a succession of headlands, bays, and 

 combes, a very considerable part actually runs unconformably to the 

 strike ; in other words, the bedding is oblique to the planes of marine 

 denudation either above or below the escarpment (instances — the 

 great Cotswold escarpment, the Eglwyseg line of cliffs near Llan- 

 gollen, etc.). With regard to Mr. Topley's statement that the line 

 of cliff now in course of being formed by the sea in N.E. Yorkshire 

 is unparalleled by any inland escarpment, I think reasons might be 

 assigned why a perfect parallelism should not be found in Britain. 

 It is not true, however, that all the escarpments of this country ex- 

 hibit a continuation of the same beds. The Lias escarpment N.E. of 

 Taunton may be regarded as a continuation of the Greensand escarp- 

 ment to the south. The escai-pment extending from Uphill, near 

 Weston-super-mare, towards the E. and N.E., embraces, in hori- 

 zontal succession, a repetition of limestone, Trias, Lias, and, if I 

 remember right, Permian conglomerate. 



Short lines of Obliquely -stratified Cliffs. — ^These may be met with 

 almost everywhere in the Lake district, and in many parts of Wales, 

 Somerset, etc. (Instances — some of the cliffs of Cader Idris ; 

 several cliffs on the S.E. side of the railway, between Penmaen Pool 

 and Barmouth Ferry Station ; cliffs in the upper valley of the Wye, 

 at high levels above the river : the cliff behind Clevedon ; many 

 cliffs at high levels on the Mendip Hills, especially between Shute- 

 shelf and Longbottom Passes, and on one side of the latter ; parts of 

 the celebrated Cheddar Cliffs, etc.). 



Strike following Sea-coasts. — Among the instances in which the 

 sea shows a tendency to follow the strike, may be mentioned the 

 cliffs to the south of Clevedon, in Somersetshire. On the sides of 

 Brean Down, near Weston-super-mare, the sea pays about equal 

 regard to dip and strike. On many parts of the west coast of Wales 

 the sea shows a preference for the strike. A whole article, detailing 

 instances in other places, might be written. It is still true, that the 

 sea pays comparatively little "regard to dip and strike," and equally 

 true that dip and strike solely determine the direction of the denuda- 

 tion effected by rain and frost. 



Synclinal Hills. — Though to Mr. Topley it may be sufficiently 

 clear, I cannot understand how a hill, consisting of a jDerfect synclinal 

 basin with the strata dipping inward on all sides (in the same para- 

 graph, in speaking of the same hiUs, Mr. Topley uses the term most 

 sides) can show a dip in any part of the face of the surrounding 

 escarpment, as they do in Eston Nab and Upleatham Hill.' I 

 venture to believe that the strata of many of the so-called synclinal 

 hills dip towards each other only from two points of the compass, in 

 which cases they do not form basins, but synclinal axes. It is 

 certain that some of these hills have this structure, and that the 

 denudation by which they have been left, has followed the strike on 

 two sides only. In their case the atmospheric theory furnishes no 

 more than half an explanation. They can be fully accounted for by 

 1 Topley, Geol. Mag. Vol. III. (Oct. 1866), p. 438. 



