W. #. Alkins—Brachiopod Beds at Cauldon, Staffs. 367 
mechanical work to be done, but its chief weakness is that it is 
not supported by sufficient evidence of tension in the crust flanking 
the lines of folding. For instance, there is evidence that the fissure 
eruptions of the North of Ireland and Scotland are of earlier date 
than the Alpine folding, and that the two did not take place 
concurrently, as is here suggested. 
Whatever may be the main cause of earth movements, there are 
no doubt many minor causes which affect the results. It is possible, 
for instance, that the tidal waves in the crust which, Michelson has 
shown by the use of his interferometer to attain a height of 2 or 
3 feet, may determine the formation of north and south joints, © 
especially in the tropics, and affect the edges of oceanic areas. 
Fauna of the Brachiopod Beds at Cauldon, Staffs. 
By W. HE. Atkins, M.Sc. 
N a recent note! Mr. J. Wilfrid Jackson, F.G.S., and the writer 
mentioned the occurrence at Cauldon, Staffordshire, of 
highly fossiliferous limestones, resembling those of the “‘ Brachiopod- 
beds ” of Castleton, Park Hill, Narrowdale, Thorpe Cloud, and other 
stations on the north-west, west, and south-west of the Staffordshire- 
Derbyshire limestone massif. It will perhaps be of interest to put 
on record the fauna of these beds, as far as it has yet been worked 
out, since the conditions under which they occur renders it highly 
improbable that any considerable amount of material will ever be 
available from them, and since they represent a phase which does 
not, so far as is known at present, occur to any extent in the more 
immediate neighbourhood of this station. 
At the village of Cauldon, very pure and very fossiliferous soft 
white limestones have been found to occur at the east end of the 
churchyard, whence they extend some little distance south in the 
direction of the large quarry on Cauldon Low, as is shown by a small 
exposure in a field between the church and the Waterhouses Road. 
Unfortunately there are no large exposures of these beds, and the 
material on which this note is based has been obtained almost 
entirely from stone quarried out during the sinking of grave-shafts. 
At the west end of the churchyard the limestone is totally different 
in character ; it is hard and slaty, and contains practically no fossils. 
The absence of sections renders obscure the relationship of these 
beds to each other, and also to the massive limestones of Cauldon Low 
itself, which appear to belong to a relatively low horizon—C-§,. A 
noteworthy feature is the occurrence of many “ pot-holes’’ in and 
about the churchyard. 
According to the 1 inch Geological Survey map (72 N.E.), the 
limestone here is cut off from the Pendleside Series by faults on the 
north-west and north-east sides, but no faults are shown between 
Cauldon Low and Cauldon Church. The slight eminence on which the 
1 Grou. Maa., Vol. LVI, 1919, p. 59. 
