Vol. 59.] A LOWER-GREENSAND FOSSILIFEROUS BAND. 237 



Description of the Sections. 



As already mentioned, the exposures occur in a series of large 

 sand-pits on the southern slope of Shcnley Hill. Their position is 

 indicated on the sketch-map (fig. 1, p. 235). These pits are opened 

 mainly for the purpose of obtaining a clean white quartz-sand, known 

 as ' silver-sand/ which is highly valued for filter-beds and other 

 purposes, and is sent out of the district in large quantities. 



This material is dug in a group of contiguous pits (shown in the 

 plan, rig. 2), among which the largest workings are known as 

 ' Garside's Pit,' on the south-east ; ' Bigby Harris's Pit,' con- 

 terminous with the former on the west ; and ' Chance's Pit,' in the 

 adjoining field north of Garside's. These pits cover an aggregate 

 area of 400 yards by 300 ; the sand is removed to an average 

 depth of 15 feet, and the excavation partly refilled with the heavy 

 capping of Drift and Gault-Clay, which has to be taken off before 

 the valuable ' silver-sand ' can be reached. At first sight the sands 

 appeared to be unfossiliferous, and indeed looked most unpromising 

 for fossils. 1 But, while traversing the spoil-heaps during our first 

 visit to the place, some blocks of hard, horny-looking, gritty lime- 

 stone arrested our attention, and these on further examination were 

 found to contain fossils. Search was made in the pit-sections for 

 the bed from which the blocks had come, and the band was soon 

 identified in Rigby Harris's Pit, where the working-face revealed 

 the bed in place, as shown in fig. 3 (p. 238 j. 



This section represents the clearest development of the fossil- 

 band in the pits ; but the bed may be traced, with constant minor 

 variation, from point to point, wherever the junction of the Gault 

 and Lower Greensand is visible in the sides of the pits. In the 

 southern portion of Garside's Pit, however, as the bed approaches 

 its outcrop at the surface from beneath the Gault it becomes 

 decomposed to an ochreous marl, wherein organic remains are 

 scarcely recognizable ; and it has also been slightly disturbed by 

 glacial agencies, which have mingled parts of the thin covering 

 of Gault with the Boulder-Clay. In Chance's Pit, where the 

 overlying Gault is 6 feet thick, covered by 4 or 5 feet of Boulder- 

 Clay, the iron stone -floors associated with the calcareous concre- 

 tions are as well-marked as in the section figured on p. 238 ; and 

 between them we found casts of fossils in decomposing ochreous 

 material, but saw none of the hard limestone-masses in place at the 

 time of our visits, as they were obscured by talus. Some fossils in 

 situ were, however, dug out by the foreman of the pit in the presence 

 of one of the authors. Large blocks of the fossiliferous rock were 



1 This discouraging aspect of the sands explains how it has happened that 

 the fossils have remained so long undiscovered. The pits were visited in 

 1897 by the Geologists' Association, and are described in Proc. Geol. Assoc. 

 vol. xv, p. 184. In this description it is observed that the junction of the Gault 

 and Lower Greensand ' is marked by a nodular bed of ochreous clay and 

 ironstone,' and that ' drift-wood was found ' in the pits, ' but no other fossils 

 were seen.' 



