A. J. Juliet-Browne — Lower Greensand in Dorset. 467 



its own. Near Bedchester this terrace, or dip-slope, is nearly half 

 a mile wide ; thence it can be traced southward to Farrington, where 

 it bends westward, still making a prominent feature, and passing 

 above Fontmell Parva it runs into a hollow by Child Okeford on the 

 eastern side of the Stour valley. 



The length of this tract is between four and five miles, but only 

 two good exposures have yet been found along it. These are, how- 

 ever, sufficient to give some interesting details of the beds which 

 constitute it. One of them is a road-cutting by Piper's Mill, between 

 Bedchester and Fontmell Magna, and to expose this more clearly 

 two narrow trenches were cut down the bank. By this means the 

 following beds were observed : — 



Feet. 



Brown loamy soil 1 to 2 



Mottled brown and grey clay containing in the lower part 

 pebbles of vein quartz and lydianite as large as beans 



(? base of Gault) 2 



Greenish -brown sand with clay mottlings 2 



Soft purple brown clay (1 foot) passing into dark green 

 sandy clay, with laminae of purple clay and patches of 

 greenish-brown sand, and finally into mottled sand, 



brown, yellow, and green 5 



Purple black laminated clay and sand 1 



Greenish -black clay full of glauconite grains 2|- 



Hard brown sandstone cemented with oxide of iron ... OJ 



Eather coarse yellowish-brown sand 1^ 



Fine soft greenish-grey sand, seen for 2 



about 18 



The other exposure in a sand-pit east of Bedchester seems to 

 begin where this leaves off. It shows remnants of the ferruginous 

 sandstone underlain by greenish-brown sand with two layers of 

 coarse yellowish sand and then 6 feet of fine greenish brown 

 sand, below which is some 5 or 6 feet of dark-green glauconitic 

 sand. This last is well exposed along the gully of the watercourse 

 that runs by this spot toward Piper's Mill. 



From these particulars it appears that the total thickness of the 

 sands near Bedchester is at least SO feet, and probably between 

 30 and 40 feet. There are some thin layers of coarse quartz sand 

 in the upper part, but the greater part is fine sand consisting of 

 small even-sized grains of quartz (not much rounded), and grains 

 of dark-green glauconite, many of which are smaller than the 

 quartz-grains. 



The occurrence of the dark glauconitic mud or clay is particularly 

 interesting, both as showing that we are not here dealing with a 

 littoral or very shallow water deposit, and also because a similar 

 bed, consisting of black clay in the upper part and dark greensand 

 below, was found in the Vectian of the Vale of Wardour. The bed 

 at Piper's Mill appears to consist of an intimate mixture of dark 

 purple-grey clay and very fine glauconitic sand, chiefly glauconite, 

 with some minute grains of quartz and mica. 



It may be mentioned that a boring made at Fontmell Brewery 

 a few years ago has been carried through the Gault into sand 



