Vol. 62.] FOOTPRINTS FEOM THE PERMIAN OF MANSFIELD. 125 



7. On Footprints from the Permian of Mansfield (Nottingham- 

 shire). By George Hickling, B.Sc. (Communicated by 

 Prof. W. Boyd Dawkins, M.A., D.Sc, E.R.S., E.S.A., F.G.S. 

 Read January 10th, 1906.) 



It is the object of this brief communication to call attention to a 

 series of footprints discovered so long ago as October 1897 by 

 Mr. Francis Holmes, of Leicester, the description of which has 

 been delayed by the lamented death of the geologist to whom we 

 owe their preservation, the late Mr. James Shipman, F.G.S., of 

 Nottingham. 



I. Notes on the Strata. 



These impressions were obtained from the Hock-Valley Quarry, 

 Mansfield, in the Permian rocks north-east of the town, some 500 

 yards from the Permo-Triassic boundary, where they are overlapped 

 by the Lower Mottled Sandstone. The rock which is here quarried 

 is a lenticular mass of sandstone intercalated in the Magnesian 

 Limestone, described by Aveline in the Geological Survey-Memoir 

 on Sheet 82 S.E. 2nd ed. (1879) pp. 10-12, as a locally-sandy type 

 of the limestone, passing laterally into the normal type. The 

 stone is here yellowish-red in colour, becoming almost white on 

 the opposite side of the town. It is by no means pure sandstone 

 throughout, but contains irregular bands of ' bastard,' a term used 

 by the quarrymen to indicate a calcareous sandstone. Every 

 gradation may be found between a pure sandstone and the almost 

 pure limestone. 



The general succession in this quarry appears to be as follows, in 

 descending order, though all the beds vary greatly in thickness : — 



Feet. 



1. Limestone 15 



2. Laminated ' bastard ' j , ~ 



3. Coarsesandy 'bastard' J 



4. Sandstone, with bands of ' bastard ' 20 



5. Limestone , ? 



Current-bedding is developed on a large scale, some of the beds 

 of sandstone having an apparent dip of as much as 25°, although the 

 true dip would appear to be quite trifling. Examples may be seen, 

 too, of contemporaneous erosion. 



A detailed examination of the Permian round Mansfield led 

 Mr. Shipman to conclude that these intercalated sandstones 

 probably were formed as sandbanks off the mouth of some river 

 flowiug from the then newly-formed Pennines, and that the actual 

 shore-line lay some 3 or 4 miles to the west of the town. v To these 

 conclusions he was led mainly by the generally-lenticular form of the 

 deposits, the varying coarseness of the sediments, and the nature 

 of the current-bedding. 



Q. J. G. S. No. 246. l 



