Geology of the Neighbourliood of Weymoutli, Sgc. 27 



shire, and Yorkshire. The Trigonia clavellata and Melania Heddingloniensis 

 are among- the most abundant. 



Another feature which is wanting in Oxfordshire, is the highly ferruginous 

 character which this oohtic formation assumes near Weymouth, particularly 

 in its upper beds inimediaiely below the Kimmeridge clay ; the same fer- 

 ruginous character prevails also in other parts of its course through this 

 district, and very remarkably in the hills near Abbotsbury. In a ravine called 

 the Red Lane, immediately north of that village, the oolitic grains are com- 

 posed of a rich hydrate of iron, which, if the country afforded fuel, might 

 be wrought as an ore of the same quality with that which supplies so many 

 iron-foundries in France, from a similar granular ore in the oolite formation. 



The extent of surface occupied by the Oxford oolite and its subordinate 

 grits in the valley of Weymouth, will best be seen on the Map ; it forms two 

 parallel belts of unequal breadth and length, subjacent to the two beds of 

 Kimmeridge clay before described, and reposing on two other parallel belts 

 of Oxford clay ; these oolitic belts terminate in two ridges, overhanging the 

 Oxford clay, with two escarpments that face towards each other ; the most 

 southerly of them extends nearly two miles west, from the tovvn of Weymouth 

 to the Fleet at Linch, and is about one mile broad ; the northern ridge and 

 its escarpment occupies a length of twelve miles, from the cliffs of Osmington 

 to the sea at Abbotsbury, terminating in an escarpment towards the soutli, 

 which presents its highest inland elevation in Linton Hill near Abbotsbury. 

 In no part of its course does it much exceed half a mile in breadth, excepting 

 at its western termination near Abbotsbury, where it widens to about a mile, 

 from the effect of the great fault hereafter to be described ; here also it 

 changes its dip from north, first to east, and then to south, bending round and 

 enlarging itself like the bowl of a spoon, whose handle is represented by the 

 long ridge of Linton Hill, just mentioned. The towers of St. Catherine's 

 Chapel at Abbotsbury, and of Wyke Regis Church, are two remarkable land- 

 marks, placed respectively near the western termination of the northern and 

 southern belts of oolite just described, and serve as points by which their 

 course may be recognised from the Dorchester road and hills adjacent to it 

 near Weymouth. In the Vale of Bredy, the oolite occurs only in a very 

 narrow band, extending about a mile from east to west, from Kingston House 

 to the village of Litton Cheney ; it is seen only in a few old quarries near 

 these two places, and in a hollow way at Litton Cheney, where it appears 

 much disturbed by a fault, and brought, as at Abbotsbury, almost into close 

 contact with the base of the escarpment of the chalk. 



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