66 PROCEEDINGS COTTESWOLD CLUB 1912 



A "SWALLOW-HOLE" IN THE INFERIOR OOLITE, 

 NEAR CHELTENHAM. 



BY 

 L. RICHARDSON. 



About half-a-mile to the east of the Seven Springs are 

 two outliers of Fullers'-Earth clay capped with Great Oohte. 

 The Fullers' Earth rests upon the Inferior Oolite, and this, in 

 turn, upon the Upper Lias, of which the uppermost 10 to 20 

 feet is probably sand, the rest clay. 



At a place in a corner of a field, best described as situated 

 above the letter "N" in " Needlehole " on the i-inch Ord- 

 nance-Survey map, Sheet 235 (3rd Ed.) or on the map in my 

 "Handbook to the Geology of Cheltenham " (1904), is a de- 

 pression, in plan triangle-shaped, each of the sides about 40 

 feet long, 12 to 15 feet deep, and narrowing downwards so 

 that the lowest portion is circular with a six-foot diameter. 

 Into this hollow trickles water from three separate sources, 

 and yet the hollow does not fill. The hollow is situated at the 

 edge of the more northern of the two outliers of Fullers' Earth. 

 Water running off the Fullers' Earth has found a way straight 

 down through the porous Oolite to the relatively impervious 

 Upper-Lias clay. In a tield to the west may be traced a slight 

 hollow, running westwards. Following this hollow, the obser- 

 ver will find that it continues into the wood, where it rapidly 

 develops into a deep valley, but subsequently into a shallow 

 depression, which is continuous to the artificial lake below the 

 Seven Springs. It would seem probable that when the water 

 is lost sight of in the " swallow-hole " it pursues an under- 

 ground course indicated at the surface by the dry valley 

 described above. 



This is the only case I know of in the Cotteswold Hills 

 where water disappears into a depression of relatively small 

 size, which merits the term "swallow-hole." There may be 

 others, there probably are, and it would be interesting to 

 hear of them. 



