CARBONIFEROUS LIMESTONE SERIES. 
195 
uppermost S 2-beds are seen dipping at 6o° W.S.W. Few 
better exposures of the Concretionary beds of S 2 are seen in 
the whole of the Bristol district. The sudden folding of the 
rocks at this point is accompanied by a local change of strike 
of a full right angle, a remarkable fact as no other signs of dis- 
turbance have been noted in the neighbourhood, and a short 
distance further W. at the Iron Plantation the normal strike is 
resumed. 
In the field J mile S.E. of Long wood House upper S2-beds have 
been exposed in making golf-bunkers. Sixty Acre Plantation 
and the northern part of Ashton Hill Plantation are formed of 
S-beds. There are no quarries here, but many blocks are 
scattered about. The northern part of the Tyntesfield estate 
consists of S-beds, which are seen in the old quarry behind the 
building N. of the chapel, but there are no very satisfactory 
exposures to the K. of the tongue of Trias, which stretches north- 
wards from Tyntesfield Farm. There are quarries in massive 
S 2 limestone with abundant Lithostrotion martini in the S.E. 
corner of the wood known as Sidelands and to the west of the 
Battleaxes, Wraxall. The Seminula-oolite, a compact white 
limestone is seen at various points near Parsonage Farm, and the 
exposures at the southern end of Wraxall Hill are in Si, consist- 
ing of compact limestone with china-stone and Seminula-bands. 
In the neighbourhood of Wraxall Church another tongue of 
Trias extends northwards. To the W. of it near Ham Farm are 
several exposures of white oolite recognisable as the Seminula- 
oolite by the fossiliferous character. Underlying the oolite is a 
strong band of grit exposed in the fields to the W. of the lane 
crossing West Hill. There is a similar strong band of grit in 
S 1 in the Olveston area. 1 From Birdcombe Court a narrow 
band of S i-beds extends westward to Tickenham Church. The 
best exposure is in a small quarry N. of Jacklands Bridge, where 
the red shaly partings between the limestone bands are crowded 
with Diphyphyllum, a coral which is found at the same level in 
the Avon Section. S i-beds with china-stone bands and 
Seminula are seen at the southern end of Church Lane, Ticken- 
ham, and at various points westward from the church for a dis- 
tance of 250 yards. No Seminulcu-beds are to be seen to the 
W. of this point. As Vaughan 2 points out, there is no room 
for the whole sequence between the S i-beds of Tickenham 
Church and the Coal Measures of the neighbouring Nailsea Coal- 
field. There is no evidence to show whether the Coal Measures 
are faulted against the Carboniferous Limestone or rest on it 
unconformably. The former view is the more probable one, as 
the latter would involve post-Seminula-beds upheaval and 
erosion, of which there is no evidence elsewhere in the district. 
1 See Proc. B.N.S. 4th ser., Vol. IV (1914 issued for 1913), p. 101. 
2 Bristol Paper, p. 232. 
