Geological Society of Glasgow, 293 



of Garscadden House. It is 298 feet in depth ; 264 feet consist of 

 sand, gravel, and mud, with 33 feet of Boukler-clay at the bottom. 

 As the surface of the ground at Drumry is 68 feet above the sea 

 level, and the depth of the bore 298 feet, consequently if the surface 

 deposits were all removed, the sea would stand at Drumry 230 feet 

 in depth. The knoll upon which Garscadden House is built rises 

 78 feet above this bore. It is probable, therefore, that the surface 

 deposits under the house are 376 feet in depth. The next bore in 

 the line of this great hollow is that at the Mains of Garscadden, 219 

 feet in depth, from the details of which it is probable that this 

 hollow had an existence early in the glacial epoch. The next deep 

 bore in its course is at New Kilpatrick, 222 feet, most of which 

 was sand and gravel. Near Kilmardinny House a bore was driven 

 to the depth of 240 feet without reaching the rock. The next is the 

 deep bore at Millichen. As the top of the bore is 134 feet above sea 

 level, and the bore itself 355 feet in depth, this gives 221 feet as the 

 actual depth of the bottom of this hollow below sea level. The 

 only height in the neighbourhood of which we are certain is where 

 the Eoman wall crosses the road at 214 feet above sea level, which 

 consequently gives 435 feet as the probable depth of the surface- 

 deposits under the Eoman wall. So we may be certain that the 

 Eoman navvies who dug the ditch which now forms the only 

 remains of the wall, were in no danger of touching the rock-head in 

 their excavation, and that the supply of raw material for earthworks 

 was here inexhaustible. The next bore is that at West Millichen 

 already detailed, 200 feet, and the last definite bore — the re- 

 maining bores being imperfect from not exhausting the surface, or 

 unsuitable from not being driven where the hollow is deepest. The 

 following are their situations and depths : — Summerston, 150 feet, 

 without reaching the rock; Buchley, 127 feet; Torrance of Campsie, 

 108 feet ; Springfield, near Kirkintilloch, 212 feet, but only 111 feet is 

 certain surface; Inchbreck, 110 feet; Auchenreoch House, 62 feet; 

 Gavell, 72 feet ; Dumbreck, 120 feet, without reaching the rock, but 

 another bore near the same place reached it at 72 feet ; Dennyloan- 

 head, 92 feet; Larbert Junction, 120 feet; Camelon, near Falkirk, 

 104 feet; and, finally, at Skinflats, within a mile of Grangemouth, a 

 bore was driven through the estuarine mud to a depth of 240 feet, 

 without reaching the rock. As the surface of the ground at Skin- 

 flats is only 17 feet above sea-level, the surface deposits must be 

 more than 223 feet below sea-level. Such is the strange fact which 

 these bores reveal — a great, deep hollow, fairly splitting Scotland 

 in twain. 



The third series of bores indicate the depth and character of the 

 bottom of that branch of the glacial sea which extended from Paisley 

 over to Garscadden, a distance of fully five miles, in which space 

 more than 50 bores demonstrate the geography of the glacial sea- 

 bottom more effectively than if an Admiralty survey of it had been 

 taken when it was yet recent, and the water in it. It is shown to 

 have been very uneven, as much marked by heights and hollows as 

 any boulder-hillocked region on dry laud. Nine of these bores, one 



