Vol. 54.] NATURAL GAS IN EAST SUSSEX. 569 



depths from the surface :— 600, 604, 617, 622, and 651 feet. Fossils 

 were scarce or absent in those parts of the clay which were richest 

 in petroleum. The lower shales in the clay smelt strongly of 

 petroleum, and burnt with a brilliant yellow flame. 



The lighter gases given off from the lower beds probably rise 

 through the more porous rocks and fissures, ai^d may be found in 

 more or less abundance, according to the varying structure and 

 texture of the rocks at different horizons. Of course the richest 

 supply will be that which is held back by some comparatively im- 

 pervious band — ^especially where such band forms an unbroken arch 

 in an anticlinal. In such cases the gas will collect within the 

 dome or arch by specific gravity, from the lower-lying porous rocks 

 covered by the impervious roof; and the higher up the anticlinal 

 the arch is pierced, the greater will be both the supply and the 

 pressure. At Heathfield the borings pierce the southern slope of a 

 great anticlinal which runs from Pairlight far into Mid-Sussex. It 

 is joined at Heathfield by another considerable anticlinal running 

 through Burwash, and it is here that the lowest strata in Sussex 

 are exposed by upheaval and denudation. The gas rising through 

 the lower petroleum-bearing rocks in the course of ages has probably 

 become ' trapped ' in the dome formed by the more clay-bound 

 strata of the Lower Ashdown Beds, the Fairlight Clays, and the 

 probability is that over the whole of the higher lands of this district 

 the natural gas will be found to occur. 



1. Section at Heathfield New Hotel. (493 feet above O.B.) 



Thickness Depth 



Feet In. Feet In. 



'Dark brown rusty ferruginous sand, with 



very thin bands of lignite 5 5 



^ j Light yellow and grey sand, with thin bands 



bB] of lignite 5 10 



Q I Slate-coloured marl 1 11 



1^ Yellow and white bands of sand 10 21 



Sandstone and blue marl in layers 11 32 



White sandstone 18 50 



White sandstone, and layers of clay and 



marl 9 59 



Bluish sandstone 2 61 



Bluish sandstone and layers of marl 10 71 



White and yellow sandstone , 5 76 



Bluish sandstone and marl 10 86 



Bluemarl 3 89 



Sandstone and marl 5 94 



Bluemarl 57 151 



Hard sand-rock 4 6 155 6 



Bluemarl 12 6 168 



Hard stone 1 6 169 6 



Hard blue marl 46 6 216 



Sand-rock 3 219 



Blue marl (gas first noticed at 228 f^et) ... 30 249 



