THE CORALLIAN ROCKS OF ENGLAND. 



305 



beds in the neighbourhood, we have no doubt that the red soil here 

 is the representative of the Upper Calcareous Grit ; but the sands 

 and clays below, being overlain by oolitic rock, which never occurs 

 in the tipper Calcareous Grit, and to which the red earth is uncon- 

 formable, and being in the position of similar beds at Highworth 

 and elsewhere, we take to be a continued representation of the 

 arenaceous form of the infra-coralline beds, the erosion being an 

 interesting indication of the wide separation in time of the oolite 

 shell-beds and the Coral Rag. These conclusions are confirmed by 

 sections at Marcham. 



All the openings hereabouts are in somewhat the same horizon, 

 and carry on the sequence of the various divisions, till in the neigh- 

 bourhood of the last-named village the calcareous type of the infra- 

 coralline beds sets in, and we have Hag supported on beds of broken 

 oolite and oolitic brash. A very good example of this is seen in a 

 limepit near " Noah's Ark," a representation of which we give 

 without further description (fig. 6). 



Fig. 6. — -Section at Noah's-Ark Lime/pit, Marcham. 

 (Total thickness, 10 ft. 6 in.) 



1. Coral Bag. 2. Broken Oolite. 3. Oolite and Brash. 



4. Shell Limestone. 5. Lower Calcareous Grit. 



Elsewhere in the neighbourhood these brashy and oolitic beds 

 beneath the Rag are thicker ; but we need only give one illustrative 

 section, that in " Marcham field," whence doubtless, for many 

 a decade, the fossils have come which have been quoted from this 

 locality, and which every writer mentions. There are, however, 

 two quarries ; and it is the most southerly to which the following 

 description applies : — 



Q..T. G. S. No. 130. x 



