1870.] WILSON—RUGBY SURFACE-DEPOSITS. 193 
towards the N.N.W. The heights of points nearly equidistant along 
the Hillmorton, Dunchurch, and Avenue roads are in succession 
A403, 400, 400, 400, 392, 375, 370 feet above the sea, indicating a 
slope westward, while the heights 396, 382, 378, 355, on the Dun- 
church, Rugby, and Clifton roads, indicate a still more decided 
slope towards the north. 
The southern edge of this plateau is well defined. The north- 
eastern edge, which forms the southern flank of the Avon valley, is 
less regular, though nearly equally steep. It is broken by a suc- 
cession of lateral valleys which contain tributaries to the Avon. 
The village of Lowmorton occupies such a lateral valley; another 
is crossed by the Lowmorton and Rugby road; and an important 
valley is crossed at the Victoria works near Rugby, and by the 
Bilton road between Rugby and Bilton. 
Nature of the subjacent Strata. 
The whole cf the district under examination is Lower Lias, with 
the exception of a few patches of Middle Lias towards the south- 
east. The limestones and clays of the Lower Lias are well developed, 
and abundantly exhibited in large lime- and clay-works; and an 
admirable section of them has been the only profitable result of an 
artesian well of 1145 feet depth. The lie of the hills and valleys 
appears to be totally independent of the distribution of the clays 
and limestones; the limestones do not form the escarpments, nor do 
the clays determine the paths of the rivers; the geological skeleton 
and the actual contour have no obvious and immediate connexion 
with one another. 
Detailed Account of the Surface-deposits on the Rugby Plateau. 
At Bourton the soil is generally gravel and sand like that at 
Rugby, 12 or 13 feet in thickness, reposing on clay. At about 
30 feet depth the limestone rock is reached. This, as is pretty 
obyious from an inspection of the map, and a knowledge of the 
general strike of the strata, is the continuation of the Newbold 
limestone, and it does in fact come to the surface at the foot of the 
escarpment at Draycote, immediately below Bourton. One well at 
Bourton is 90 feet deep, 60 feet of it being in the rock. 
The same general character continues along the escarpments to 
Thurluston, which village rests on gravel cf the same or greater 
thickness. In two places, however, there are wells 50 deep feet, 
which of course indicate that the depth of the gravel there is insuf- 
ficient to supply the surface-wells with water. At Thurlaston the 
Jimestone rock is not reached; some thin bands of it which lie inter- 
stratified with the clay are passed through. 
At Dunchurch the surface-deposits are precisely the same. I have 
not been able to hear of any deep wells. The gravel and sand are 
generally about 13 feet deep. At Mr. Harrison’s house, on the brow 
near Bilton Grange, there are three wells—two in gravel, of 13 and 
14 feet, and one in clay, of 30 feet. At Bilton Grange the depth of 
