554 Aubrey Strahan — Bocks beneath the Coal-measures 



with this rock against the older Palaeozoic strata. The absence of 

 Waterstones, moreover, does not necessarily imply the presence of a 

 fault, for these beds constitute merely the earlier and more sandy 

 sediments of the New Eed Marl, and are known to be quite un- 

 represented in some other localities where the Eed Marl mantles 

 round bosses of old rock, as at Croft, Sapcote, etc. 



That there is a fault, however, along the northern part of the 

 coal-field appears to have been proved, and that it extends south- 

 wards as far as shown, though perhaps with no great throw, seems 

 probable. Near Hartshill Wharf is a quarry in quartzite in which 

 the base of the Trias is seen, the lower beds consisting of about 

 three feet of sandstone, overlain by about three feet of marl, and 

 lying upon the quartzite. The beds undulate and when last seen are 

 dipping steeply, as though near a fault. If there is a fault here, 

 the Triassic beds seen must be on the west or upthrow side. The 

 section proves therefore that the Trias rests upon the quartzite here, 

 without any of the Coal-measures intervening. 



At the brick-pit near the canal by Nuneaton Midland Station, the 

 Eed Marls are seen with a dip ranging up to 35°. The quartzite 

 rises to the surface close by, but the junction is not exposed. The 

 steepness of the dip of the Marl, however, points to the boundary 

 being probably a fault. 



We have, then, four instances in which the Trias is seen resting 

 directly upon the Silurian rocks, namely, Marston Jabet, Wash Lane, 

 the Midland Co.'s quarry, and Hartshill Wharf. This evidence 

 alone would have been sufficient to indicate that the Trias of the 

 great plain on the north-east of the Warwickshire Coal-field would 

 probably be found to rest in great part on the older Palaeozoic rocks, 

 and not on Coal-measures, especially when it is remembered that the 

 nearest exposure of Palaeozoic rock to the east (namely, at Sapcote) 

 shows syenite rising through the Marl. But this conclusion has 

 been placed beyond doubt by the results of borings, some of which 

 have reached the base of the Triassic rocks, and proved the depth to 

 the Palaeozoic floor. The following is a list of those which bear 

 upon the district under consideration. 



Hawkesbury Pumping Station ; about five miles south of Nuneaton. 252 feet 

 above Ordnance Datum. 1 



Drift 30 feet. 



Lower Keuper Sandstone [Waterstones] 90 , , : 



120 „ 

 The "White Stone, about 2J miles south-east of Nuneaton. A well to a depth of 

 80 feet, a borehole to a further depth of 50 feet. Height above Ordnance 

 Datum about 250 feet. 2 



White sandstone and red shale [Waterstones] 60 feet. 



Hard mottled blue and purple shales 70 j, 1 



130 „ 



1 Report of the British Association for 1875 (Report of the Committee on the 

 Circulation of Underground Waters), pp. 135, 136. For the Nuneaton boring see 

 also Report for 1878, Report on the Circulation of Underground Waters, p. 7. 



2 The details of this section were given me by Mr. W. Andrews. The Water- 

 stones are well exposed in a quarry by the side of the L. and N. W. Railway, near 

 Attleborough. 



