Upper Greensand. 221 



are obviously the work of ordinary denuding agencies 

 on a broader area of Greensand. It is, however, at first 

 sight somewhat surprising, to meet with a small outlier 

 of Upper Grreensand, only a few acres in extent, nearly 

 fifty miles to the west of Black Down, at Orleigh Court, 

 three miles south-east of Bideford Bay. This patch is 

 mentioned by De la Beche, in his Eeport on the Geology 

 of Cornwall, Devon, and West Somerset, and of late its 

 existence as a solid outlier has been doubted. There 

 is, however, so much angular chert on the spot, that 

 sufficient material remains to show that the Greensand 

 once spread westward so far, and in my opinion pro- 

 bably much farther. 



Throughout these areas, the Upper Greensand may 

 be briefly described as consisting of yellowish brown 

 sand, partly compact, partly soft, with layers and 

 detached pieces of chert, and towards the base it is 

 partly green with specks of silicate of iron. The sands 

 are often coarse, and contain layers of shells, frequently 

 broken and fragmentary. The whole is little more than 

 200 feet in thickness. 



East of Lyme Regis, this Greensand appears near 

 Abbotsbury, on the southern and western flanks of the 

 Chalk Downs at Whitehill. West of Chideock outlying 

 patches lie on the marlstone of the Middle Lias, 

 between Chideock and Bridport on the sand that 

 underlies the Inferior Oolite, at Abbotsbury Castle on 

 the Forest Marble, and from thence stretching north 

 and west, at Shipton Beacon they lie on the Fuller's 

 Earth. Beyond this the Cretaceous strata make a 

 great curve east of Poorstock and Beaminster, lying 

 generally on the Fuller's Earth. East of Cheddington, 

 for some miles the Greensand lies on the Oxford Clay, 

 then for a short space on the sand of the Calcareous 



