588 Prof. T. Rupert Jones — On Sarsden Stones. 



As the whole of this denudation, which otherwise would go 

 unnoticed and unmeasured, must have taken place since last spring- 

 tide, we see what an enormous mass of sand has been moved since 

 that time. The greater part of this no doubt does not get beyond 

 the reach of the tide, and is blown on to the higher parts of the shore, 

 to be perhaps again washed into the sea. Moisture is essential to the 

 production of these little ridges — shall I call them "Eolites"? — and 

 it is instructive to observe on the extreme upper and dry part of the 

 shore that the effect of the wind is to cause ripple marks at right 

 angles to its direction, and almost undistinguishable from true water 

 ripple marks. I estimate that the denudation has been fully \ of an 

 inch or 33 cubic yards per acre in about a week, or say 2000 tons 

 along our two miles of shore. It would be interesting to know 

 if any geologist has ever unearthed a fossil answering this description. 



[See a letter from Mr. Joseph Duff in Geol. Mag. 1865, Vol. II. 

 p. 136, on Carboniferous Sandstone with surface-markings (Plate IV.), 

 also one from the late Alexander Bryson, Esq., F.R.S.E., on Surface- 

 markings on Sandstone (with a Woodcut), op. cit. p. 189. The 

 wave-like and rippled arrangement of the surface of the sand in the 

 Sahara caused by the prevalent N.E. winds has frequently be^en 

 alluded to by travellers. See Elisee Reclus " The Earth," Section I. 

 English edition, edited by H. Woodward, F.R.S., 1871, p. 93.— 

 Edit. Geol. Mag.] 



V. — Notes on Some Sarsden Stones. 

 By Prof. T. Etjpert Jones F.E.S., F.G.S. 



I. Concretionary with Calcareous Cement. — Last autumn the Rev. 

 John Adams, of Stockcross, kindly took me to see the interesting 

 specimen of Sarsden Stone in situ at Langley Park, north of New- 

 bury, Berks, which he described in the " Transact. Newbury District 

 Field Club," vol. i. 1871, p. 107, and in the Geol. Mag. Vol. X. 

 p. 200 ; and which has also been described by Mr. W. Whitaker in 

 the "Memoirs Geol. Survey," vol. iv. p. 193. This concretionary 

 Sarsden Stone, belonging to the " Woolwich and Reading " series, 

 consists of quartz grains with a Calcareous cement. This is an un- 

 usual circumstance for " Sarsden Stone " ; and points to the former 

 presence of Shells, perhaps, or of calciferous waters, in that portion 

 of the Lower Eocene series. A somewhat similar quartzose sand- 

 stone, but with smaller and more uniform globules held together by 

 carbonate of lime, occurs in the Hastings Sandstone at the East Cliff, 

 Hastings ; and another in the Triassic series of Brunswick. In the 

 concretion aiy sandstone from Langley Park, the lines of stratification 

 are clearly apparent here and there on the weathered sides of the 

 globular, botryoidal, and mammillary masses. These do not show 

 a distinct radiate structure, such as is more or less visible in those 

 from Hastings and Brunswick ; and these, again, are of course less 

 radiate within than the far more purely calcareous concretions of the 

 Magnesian Limestone of Durham. 



II. Boot-marked. — In a piece of the usual hard siliceous quartzose 



