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the Uley valley and the escarpments of Frocester hill and Uley 
Bury, no trace of the shelly Great Oolite can now, so far as I 
am aware, be found to the south-westward of the line. The beds 
gradually increase in importance towards Minchinhampton 
Common, where the typical section is seen. From thence they 
extend eastwards through the hills north and south of the 
valley of the Frome at Chalford, and finally dip under the White 
Limestone in the Edgeworth valley. 
From the circumstance of these beds merging into Weather- 
stones, composed chiefly of sand and shelly detritus, it seems 
probable that the shells were originally deposited not far from 
a shore, and were ground up into fine detritus, which was spread 
over a large area, and eventually consolidated into the Weather- 
stones, as described by Lycrrr.—that another large deposit of 
shells took place, under conditions more favourable to their 
preservation, as will appear from an examination of the shelly 
beds of Minchinhampton Common, but even in these favoured 
areas the conditions ultimately changed, as is shown by the 
condition of the shells found in the planking beds, which are 
usually worn, and appear to have undergone much rolling before 
they were finally deposited. Other evidence of the proximity 
of land is seen in the abundance of plant remains in the 
Weatherstones, as well as the Forest Marble, throughout the 
area I have described. , 
The break between the White Limestone and the overlying 
beds is well defined in the Sections at Tiltup’s End, and the 
occurrence of a layer of fossils in two localities just at the 
line of junction—the beds above and below not being very 
fossiliferous—followed by a change in the character of the 
deposits from a pure fine-grained chalky Limestone to a coarse 
sandy rock, made up of shelly detritus, sand, and Oolitic 
granules, points to a period of cessation of deposits, followed 
by a change of conditions, and probably of elevation of sea 
bottom. The Geological Surveyors were therefore right in 
making this horizon the line of separation between the Great 
—Oolite and the Forest Marble, although this line is now con- 
sidered merely as one of sub-division; and the Forest Marble is 
more usually regarded as a member of the Great Oolite series. 
