226 



Spiropora and Apseudesia. A similar bed can be seen at the base 

 of the tnmbled oolites of the ParJcinsoni-st&ge near Bourton. 



Upon crossing the vale of Moreton and reaching the neighbourhood 

 of Chipping Norton one finds the ragstones, in some localities 

 approaching the Pholadomya-grit of Dr. Lycett*, resting boldly upon 

 the thin beds of the Upper Lias. In a brickyard at Salford the un- 

 conformability between the two formations is well marked, and the 

 remains of an interposed fine-grained freestone bed are to be seen. 



N. E. Counties. — As in the marine strata of the west there is 

 thinning-out of the beds in their north-east course, so in the south- 

 west range of the Upper Estuarine series and the Lincolnshire Lime- 

 stone there is constant diminution of thickness. The disappearance 

 of the latter has been noted at Geddington, north-east of North- 

 ampton, by the late Mr. S. Sharp in his excellent paper on the 

 Oolites of Northamptonshire. The " Northampton-sand " series, as 

 may be seen by reference to Prof. Judd's tables f , diminishes in 

 thickness towards Northampton, where, however, it again acquires 

 a great development only to thin away again in its south-west 

 course towards Oxfordshire. 



North Oxfordshire. — Mr. Hudleston writes t " Under the term 

 i Northampton Sand ' are included in North Oxfordshire the whole 

 mass of variable sandy strata (passing at some points into imperfect 

 ironstones, and at others into impure limestones) which intervene 

 between the Upper Lias Clay and the marly limestones of the Upper 

 Zone of the Great Oolite. Such an essentially provisional arrange- 

 ment may suit in some places ; but at Chipping Norton it is certainly 

 liable to mislead, as we have the conventional namesake of the true 

 Northampton Sand, which at Northampton comprises the zones of 

 A. Murchisonce and A, opalinus, superposed on the Cli/peus-grit or 

 A. Parkinsoni zone — in other words the Inferior Oolite is turned 

 upside down.'' 



The coming together in the Inferior- and Great-Oolite systems of 

 beds somewhat similar in lithological composition has been a frequent 

 source of perplexity to the officers of the Geological Survey. 



In the north-east corner of the map previously mentioned is 

 situated the town of Banbury, flanked eastward by the valley of the 

 Cherwell. To the extreme south-west lies Chipping Norton, west 

 and north-west of which stretches the vale of Moreton with its 

 easterly boundary of the oolitic outliers of Tysoe Hill, Brailes Hill, 

 Long Compton Hill, and the Addlestrop and Bollright plateaux. 



Before passing on to the description of the area, which in great 

 part seems to be covered by beds ranging higher in the Inferior- 

 Oolite system, it will be well to pay attention for a short time to a 

 somewhat abnormal series of oolitic limestones at Coombe Hill, about 

 5 miles south of Banbury. The beds, the remains of which were 

 formerly worked at Blackingrove, on the opposite side of the valley 

 to Coombe Hill, have been let down by a fault. The following is a 

 section : — 



* Cotteswold Hills, p. 68. t Geol. Kutland, pi. 1. 



\ Proc. Geol. Assoc, vol. v. p. 383. 



