ON THE ERRATIC BLOCKS OP ENGLAND, WALES, AND IRELAND. 189 



bonlder is mentioned. Some distance S.E. of Cefn, and about a quarter 

 of a mile S.E. of Chirk Bridge, on the east side of the Holyhead road, there 

 is a felstone boulder, the greater part of which is evidently buried. The 

 exposed part is about 13 x 7 feet, and three feet above ground. Between 

 this boulder and Welsh Frankton, Arenig erratics are numerous, and 

 some of them are very large. A short distance west of Welsh Frankton, 

 and close to where a canal is crossed by the main road, 8x8 feet of an 

 Arenig boulder may be seen above ground. It is somewhat varied in 

 structure, part of it approaching the character of hornstone. Around 

 Welsh Frankton there are numerous moderate-sized, and a few very large 

 Arenig boulders, One, close to Mr. Oswell's house, is quite 8 feet in 

 average diameter ; and another, a few yards distant, 8| x 6 X 5 feet. 

 They are accompanied by good-sized boulders of Silurian grit and Carboni- 

 ferous sandstone and quartzite from the Welsh borders. 



Mr. Mackintosh lately found a number of lumps of a very white rock 

 in a gravel-pit which had been excavated in an undulating continuation of 

 the Wge and abrupt mounds of middle drift age which may be seen south 

 of Ellesmere, Shropshire. He has since found many more lumps at 

 Wrexham, and, after much inquiry, he cannot hear of any rock like it in 

 situ. It looks very much like silicified chalk, but the fossil evidence is 

 in favour of its Jurassic age. A fragment of lias, with characteristic 

 fossils (now in the possession of Mr. W. Shone), was very lately found 

 about 8 feet down in upper boulder clay at Guilden Sutton, near 

 Chester; and Mr. Watts, F.G.S., has found large chalk flints and a 

 specimen of Grypluea incurva in a boulder clay at Piethorne, near Rochdale. 

 These erratics, in all probability, came from Ireland. 



Mr. Moltneux reports as follows upon Boulders in the Midland 

 District : — 



Stretching westwards from the town of Burton-on-Trent, and bounded 

 on the south and east by the Trent Valley and on the north by that of the 

 Dove, is a range of table-land, from 100 to 300 feet above the levels of 

 those rivers, and comprising within its limits the broad acreage anciently 

 included in the Royal Forest of Needwood. The whole area is covered 

 more or less thickly with one or the other or each of the three different 

 deposits which constitute the Boulder clay group of the Midlands. These 

 deposits consist in well-defined divisions of sand, gravel, clay, and boul- 

 ders, and are of an aggregate thickness of 120 feet. On the iess elevated 

 face of the country under consideration they repose directly on Red marls, 



and on the higher tracts of Christchurch-on-ISreedwood and Bagot's Park 



... . . P 



are the lower division of the Rhaetic beds, which there appear in charac- 

 teristic force and condition. The boulders, or rock masses, occur prin- 

 cipally at from three to ten feet below the surface, intermixed with blue 

 and yellow clay, and consist of angular, sub-angular, and rounded frag- 

 ments of Carboniferous limestone and chert, Yoredale sandstone, Millstone 

 grits, Granites, Porphyry, Syenite, Greenstone, Trachyte, and Toadstone, 

 with smaller fragments of Liassic and Oolitic rocks, many of which bear 

 the usual evidences of the action of ice. There is also, stretching across 

 the high grounds of Hanbury Woodend, running east and west, an extra- 

 ordinary trail of Chalk flint flakes. The Boulder clays, with their asso- 

 ciated deposits, cap the high land of Waterloo Hill and Moat Bank on the 

 east side of the Trent Valley, and the same description of rock masses 



