INTRODUCTION, xV 
readily along the bedding planes into slabs thin enough to be 
used for roofing purposes. Immense numbers of fossils, not 
only of animals but of plants, have been met with in them, 
characteristic series of which are preserved in the University 
Museum. At Sarsden there are several quarries from one of 
which bones of a pterodactyle have been obtained. As a rule this 
stone does not form good building material, but the Tainton 
quarries have produced the most durable stone in the county; 
Burford Church, Blenheim Palace, the inside of St. Paul’s 
Cathedral and many old buildings in Oxford being composed 
of this Tainton stone. 
Many sections of these beds are exposed in the Dorne and 
Evenlode valleys. On the Stonesfield bed rests a group of lime- 
stone marls and clays 20 or 30 feet in thickness, which forms 
the upper band of the Great Oolite. This bed entering the 
‘county on the west, passes by Burford and Wychwood, spreads 
out in a flat plateau on which Ditchley, Kiddington, Worton, 
Glympton, Steeple Barton, etc. are situate. It also borders the 
Windrush river at Asthal, Minster Lovell, and Witney. As it 
crosses the Cherwell it becomes much narrower, but on the 
east side of the river it spreads out into an extensive tract of 
country to the Northamptonshire boundary; Cottisford, Mix- 
bury, Fritwell, Ardley, etc. standing on it. The rock forms 
a, tabulated surface, intersected by narrow channel-like valleys 
and sloping gradually to the south at an angle of about 1° 
nearly corresponding with the dip of the beds. In fact it forms 
a repetition of the Marlstone plateau and, like that, is dotted 
over with outliers, in this case of Forest Marble capped by 
Cornbrash and Oxford Clay. East of the Cherwell it is 
covered with a thick deposit of drift which gives an undulating 
surface to the country about Cottisford and Hethe. Good 
sections are exposed by Enslow bridge, fossils are numerous, thick 
beds of Terebratula occurring in excellent preservation. The 
escarpment of the Great Oolite is much broken by faults, and 
the beds are much shaken about and tilted. The total thick- 
ness of the beds is estimated at 200 feet. The rarer plants 
found on the Great Oolite are Stachys germanica, Salvia 
pratensis, Thlaspi perfoliatum, Astragalus danicus, Cynoglossum 
montanum, Monotropa, the latter plant occurring on two small 
