﻿496 ME. A. W. CLAYDEN ON TOOTPEIl^TS IN THE ['Nov. I908, 



26. On the Occueeence of Footpeints in the Lowee Sandstones of 

 the ExETEE DisTEiCT. By Aethue William Clatden, M.A., 

 F.G.S., Principal of the E,oyal Albert Memorial University 

 College, Exeter. (Eead June 17th, 1908.) 



[Plate LI.] 



I HAVE long felt, for reasons which need not be detailed here, that 

 the Red Eock Series of the Exeter district was mainly of subaerial 

 origin, the breccias and associated sands having accumulated on a 

 strip of country bounded on the west by high hills carved out of 

 the folded Culm, while a large sheet of water lay to the east. 

 The frequent indications of aqueous deposit would be due to 

 variations in the level of the water such that it occasionally over- 

 spread much of the littoral region, and rearranged and levelled the 

 subaerial accumulations. 



Such a district seems to be exactly suited for the preservation of 

 the footprints of any animals which might descend from the hiUs 

 to wander over the low-lying sandy shores. I have, therefore, 

 repeatedly searched the surfaces of blocks freshly fallen from the 

 cliffs near Exmouth, where the 'Lower Marls with occasional 

 Sandstones' reach the coast, and every other section that I could 

 find in which the natural surfaces were laid bare. 



Sun-cracks on the surfaces of thin lenticular seams of marl are 

 often to be found, as well as other signs of the supposed conditions. 

 The upper part of some of the sandstones weathers out in a curious 

 way, leaving an irregular network of concretionary structures, 

 strongly suggestive of a matted network of underground stems, 

 such as those of the sand Carex or the recent Equisetaceae. But 

 nothing of undoubtedly organic origin has been found. 



Away from the coast suitable exposures are rare. Eoadside 

 cuttings and sand-pits do not show the bedding-surfaces, and the 

 sand is generally much too loose to give impressions. 



Hard sandstone has been uncovered close to Exeter in one of the 

 large brickfields, but its surface appears to be smooth. With this 

 exception, the brecciated marls in which these pits are excavated 

 are full of a confused mass of volcanic debris in so advanced 

 a state of decomposition that it is most unlikely that organic 

 remains would be preserved. 



The sandstones classed as ' Lower Sandstones ' in the Geological 

 Survey-map have always seemed to promise best, especially where 

 they abut upon the Culm, but suitable exposures are very rare. 

 Some of the beds afford excellent building-material which has been 

 used occasionally, but the quarries have been long abandoned and 

 are now greatly overgrown. 



Three of these old quarries are in the sandstone-district between 

 the Culm promontory of Stoke Hill and the Culm inlier of Ashclyst 

 Forest. All parts of the sand are thus but a short distance from 



