162 GEOLOGY OF WARWIcKSnmE. towards Sutton Coldfield; and along this line the Upper Mottled is for the most part capped by harder and coarser beds of the Lower Sandstone. At Aston, a very interesting boring has been made by the Bir­ mingham Waterworks Company, traversing the greater part of the into the subjacent beds. The details of this boring are as follows :-

BORING AT ASTON, 2 MILES NORTH OF . Feet Alluvial •• • • • • • • • • ~ . 10 Upper Mottled Sandstone } 232 New Red Sandstone. { Harder do. and conglomerate Red Marl •• •• •• 36 Sandstone __ •• •• 10 Permian Beds. • • Red Marl •• •• •• 15 Very hard Sandstone •• 53 Mar! with breechlo •••• 45 401

At the base of the New Red Sandstone large supplies of water were obtained. In the above section, the Upper Mottled Sandstone and Pebble beds are unfortunately classed together, so that we are un­ able to ascertain their various thicknesses. Very fine sections in the former subdivision are laid open in quarries both on the east and west sides of the town, where the beds are worked for mould­ ing sand. The probable thickness in this district will be about 200 feet. On the west side of the coalfield, we have no evi­ dence whether either of the subdivisions of the Bunter series exists, the Lower Keuper Sandstone and Keuper Marls being always brought against either the Coal Measures or Permian rocks by faults, and we therefore never obtain a complete succession of the formations. It is, therefore, quite uncertain if the Conglomerate and Red Sandstone continue underneath the Keuper Marls and sandstone up to the coalfields, but, if so, they are probably of much less thickness than they are found further to the west. It has been already shown that on the east aide of the Warwick­ shire coalfield, the conglomerate has only been found at one point, and the Red and Mottled Sandstone is known not to exist here; for we find, in the railway cutting near Polesworth, the Lower Keuper Sandstone resting immediately on the conglomerate. Thus, the Bunter beds, which attain a thickness of nearly 600 feet be­ tween Birmingham and Lichfield, thin rapidly away towards the east, till, at the south end of the ·Warwickshire coalfield, they entirely disappear, and the Keuper beds rest directly on the Car­ boniferous and Permian strata. With the Upper Mottled Sandstone, the Bunter series terminates upwards, and there is every reason to believe that th9 bed of the

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