Brodle — PJiosphatic Nodules. 153 



II. — On a Deposit of Phosphatic Nodules in the Lower Gkben- 

 Sand, at Sandy, Bedfordshike. 



By the Eev. P. B, Bkodie, M.A., F.G.S. 



THE summit of tlie hill, about two miles from the station, on the 

 property of Arthur Peel, Esq., M.P., consists of yellow and 

 brown sand, with much iron ; and the harder beds of the latter, 

 where they form a stone, are composed largely of small pebbles of 

 quartz, sandstone, and mica. In these the phosphatic nodules are 

 found. Generally they lie at a variable depth from the surface — in 

 some cases cropping out; but, in others, they prevail at a greater 

 depth, with a capjDing of soft sand from three to four feet, but none 

 have been met with below six feet from the top. The average 

 thickness of the strata exposed is two feet, now and then reaching 

 to six feet. Below is a loose sand, in which a deep well has been 

 lately sunk to a depth of fifty feet. This is on the eastern side of 

 the hill. These nodules are not uniformly spread over the surface, 

 but appear to run in patches, being occasionally altogether absent. 

 The area which they occupy, as at present worked, is limited to one 

 mile and a half in length, by a quarter of a mile in width, in a 

 straight line. The nodules are mixed with pebbles and other extra- 

 neous matter, which are carefully picked out, including masses of 

 iron. The whole sometimes forms a kind of conglomerate of 

 pebbles, iron, sand, and phosphatic nodules. West of the above, at 

 a considerably lower level, there is a large quarry of hard, dark- 

 coloured ferruginous sand-rock, which appears to dip under the sand 

 below the phosphate-bed. This stone, which is very hard, is used for 

 walls and buildings, and, though of a sombre colour, is a good 

 useful material for this purpose, as it hardens by exposure to the 

 atmosphere. The only fossils I observed in it were small pieces of 

 vegetable matter, and an imperfect cast of a species of Bhynchonella. 

 A large mass of silicified wood was obtained either from this bed or 

 the overlying sand. With these exceptions, all the other fossils are 

 evidently derivative, unless a rolled specimen of Endogenites erosa, 

 from the top of the hill, may be considered to belong to the age of 

 the Lower G-reen-sand. 



As remains of Clatliraria Lyellii have been discovered in the 

 sands near Woburn, it is probable that both these plants, so charac- 

 teristic of the Wealden, contmued to live on to a somewhat later 

 period, as indeed we know the latter did, from the discovery of a 

 most interesting portion of that singular plant in the Chalk Marl of 

 the Isle of Wight. The most numerous fossils occur in the phos- 

 phate-bed above referred to, the general character of which, from the 

 white appearance of the nodules, presents a striking contrast to the 

 beds above and below. The interior of the nodules is of a black or 

 brown colour, and often, though not always, envelop an organic 

 body, generally an Ammonite (A. Lamberti) of the Oxford Clay, 

 which is very abundant — more so, indeed, than any other species. 

 The nodules are of all shapes, rounded and elongated, and frequently 

 pitted on the surface, but comparatively of small size. Associated 

 with them there are lumps of hardened clay, which are more or 



