30 



THE GEOLOGIST. 



Mendip district and elsewhere reveal contents of Secondary age. I 

 noticed many years ago, when the railway was being made from Frome 

 to Eadstock, that lead ore had been present in the inferior Oolite, where 

 it reposes immediately npon the Carboniferous Limestone, at a spot near 

 the letter " k " in the word " Pike " on the Ordnance map, about a mile 

 (to scale) north of Frome. If my memory serves me, the ore occurred in 

 veins in joints in the Oolite. This proves that, even if the lead veins of 

 that district are not wholly of Secondary age, at any rate the deposit of 

 ore was not concluded until after the deposition and solidification of the 

 inferior Oolite. I am, Sir, faithfully vours, 



O. Fisher, F.G.S. 



Elrnstead, Colchester, Nov. 10. 



Druid Sandstone. 



Dear Sir, — In your last number of the ' Geologist,' page 450, Mr. Ben- 

 sted makes the remark, that the statement of Dr. Mantell still holds good, 

 that no regular stratum of the Druid Sandstone has yet been discovered 

 in this country ; and its geological position is still undetermined. 



The following observations will, I believe, throw some light upon this 

 question. Close to the village of Broodmayne, about five miles from 

 Dorchester, on the Wareham road, are several blocks of Druid Sandstone, 

 in two fields on each side of the road, close to a farmhouse, marked 

 "Little Mayne " on the map. These blocks have been a puzzle to the 

 local archaeologists, w T ho have endeavoured to give them an antiquarian 

 value, and to explain their arrangement as belonging to some ancient so- 

 called " Druidical " work. They are however a natural deposit, and as I 

 conceive, are, so to speak, in situ ; that is to.say, they have not travelled 

 any distance from the place where they were formed. The locality is on 

 the line of junction with the Chalk of a small outlier of the Lower Tertia- 

 ries. These beds are extremely variable in character, and at this spot a 

 fine sharp white sand crops out on the north side of the shallow valley in 

 which the blocks lie. In the side of the road this sand has been cut into, 

 and two of the blocks of sandstone are seen, one partly cropping out on 

 the surface, with its lower portion embedded in its native sand. The other 

 is entirely enveloped in the sand, except as far as it has been exposed in 

 cutting the road. 



The blocks are evidently indurated masses, or septaria of this bed of 

 sand. 



The denuding forces which have scooped out the valley, have removed 

 the sand and left the blocks behind. 



There are numerous other blocks of a similar character on and beneath 

 the lofty hill called Blackdown, near Portisham. These however are con- 

 glomerates of large flints. Some lie on the top of the hill on the upper 

 surface of the chalk, almost in situ, as at Mayne, and close to the Tertiary 

 beds from which they came ; others have been carried by some torrential 

 action into the deep valleys of Portisham and Bridehead beneath. ,. 



I remain, faithfully yours, 



O. Fisher. 



Mmstead, Colchester, Dec. 10. 



