544 T. Mellaril Rcade— 



outlines of the Boulder-clay country. There is also evidence from 

 the depth of these buried valleys that the pre-Glacial and, perhaps, 

 early Glacial land stood much higher with respect to the sea-level 

 than at present. 



When the Boulder-clay, and in some cases the sand, is cleared 

 from the surface of the rock, when this is of hard compact ston<\ 

 strias are pretty sure to be found, having usually a north-westerly 

 trend, but with considerable variation and, in most cases, divergent, 

 or even in some cross, striatums. At Little Crosby the surface of 

 the rocks was so ice-dressed that the mason who erected the village 

 cross thought it unnecessary to chisel the top surface, upon which 

 at the present moment deep and fine ice stria) are to be observed. 1 

 Extending our observations beyond the immediate neighbourhood of 

 Liverpool, we find along the Welsh coast as far as Nevin, in 

 Carnarvonshire, a similar assemblage of rocks and shells occurring 

 in the Low-level Boulder-clays and Sands, intermixed to a greater 

 extent with local rocks. These deposits show in some cases decided 

 evidences of stratification. In addition to local differences in the 

 clays the Welsh Low-level Marine Boulder-clays rest generally 

 on another clay, which I call " till," which is distinguished by its 

 assumption of the colour of the local rocks from which it is derived 

 and on which it rests, and the absence of shells and far-travelled 

 erratics. 



This deposit bears a relation to the orography of the country, and 

 is present in greatest force in the hilly and mountainous districts, 

 where it can be traced in stream courses far up the valleys. The 

 boulders are of rocks belonging to the immediate watershed, and 

 are found both rounded and striated, angular and subangular. In 

 the case of the larger valleys like the Vale of Clwyd, the marine 

 drift penetrates further iidand, but even at Rhuddlan it is seen to 

 rest on a more local clay. 2 These marine deposits are in some cases 

 continuously connected with the High-level Shelly Drifts, which 

 occur at from 1,000 to 1,200 feet, as in the range of hills extending 

 from Minera to Llangollen. 3 This connection may be traced from 

 Buabon up to the High-level sands just mentioned ; also up the 

 course of the River Alyn from its mouth to its source, and again 

 down the continuing Vale of Afon Chwiter by Caervvys to the Vale 

 of Clwyd. In this connection it has been necessary here to mention 

 the continuity of the Low-level and High-level Drifts, though I shall 

 have to recur again to the latter. 



To the eastward the Marine Boulder-cla}'s are traceable to 

 Macclesfield, where they occur at a level of about 600 feet in what 

 are known as the Cemetery beds, and an outlying and well-known 

 deposit of shelly sand and gravel is found near the " Setter Dog " 

 at a level of about 1,200 feet, 4 



1 I had the pleasure of showing this to several well-known geologists during an 

 excursion of Section C of the British Association — Liverpool meeting, 1890'. 



2 See "Geology of the Vale of Clwyd" (McKenny Hughes): Proceedings of 

 Chester Society of Natural Science, No. 3. Also, " Drifts of the Yale of Clwyd" : 

 Q.J.G.S. 1887, p. 80. 



3 Mackintosh, Q.J.G.S., vol. xxxviii, p. 184. 



4 Prestwich, E. D. Darbishire, Geol. Mag. 1865, p. 293. 





