154 Dr. FiTTON on the Strata below the Chalk. 



of the chalk itself; the sand being eroded into irregular cavities, sometimes 

 almost tubular, which are now occupied by chalk flints, a great part of them 

 in small fragments, and all of a rusty yellow colour. Equally abundant accu- 

 mulations of these are seen also on the hills of white sand (one of the upper 

 members of the Lower green), at Sledham and Trotton commons, between six 

 and seven miles east of Petersfield ; but in this case the flints are not dis- 

 coloured. This latter place is distant nearly three miles from the nearest 

 point of the chalk, and between nine and ten miles east of that where the 

 chalk escarpments are confluent. In the angle of the chalk west and north- 

 west of Petersfield, particularly in the ascent to Alton by Stoner Hill, such 

 heaps are yet more common. These facts coincide with the observations 

 already mentioned, near Boughton, Dorking, and Wracklesham (38, 66, and 

 65 ) ; so that it would seem as if chalk flint gravel above the Lower green- 

 sand was of general and frequent occurrence all around the denudation. Mr. 

 Murchison, however, adds, that he has still no knowledge of any such debris 

 beyond the limits of that formation, or within the Wealden properly so called. 



(70.) The stiff" and retentive marly beds, at the base of the Downs, sus- 

 taining the water which descends through the chalk, have produced a line of 

 ponds along the bottom of the escarpment of the South Downs; — a result pre- 

 cisely analogous to the breaking-out of the springs above the marl, at Lydden 

 Spout, upon the coast (8.), and all along the base of the Downs on the north. 



(71.) One of the chief characteristics of the tract near Petersfield, consists 

 in the great relative extent and prominence of the Upper green-sand; which 

 runs out beyond the foot of the chalk escarpment, like a step or terrace, 

 throughout the tract from Farnham, by Selborne and Petersfield, to the south 

 of Petworth, and affords some of the best sections anywhere to be found, 

 except perhaps in the Isle of Wight. Though in the parishes of Buriton, 

 Harting, &c., there is an insensible passage from the grey chalk and chalk 

 marl, into the Upper green-sand, still the whole of the terraces (there at least 

 two miles broad) are exclusively composed of what is called in the country 

 Malm-rock*. The grey or lower chalk of this portion of the South Downs 

 is charged with the Inoceramus mt/tiloides, I. Cuvieri, I. Brongniarti, and two 

 species of small plicated Terebratula, and does not contain any of the cha- 

 racteristic malm-rock fossils enumerated in Mr. Murchison's memoir ; nor 

 does the malm-rock contain, so far as his observation goes, a single specimen 

 of the genera Inoceramus and Terebratula, so abundant in the overlying 



* The Malm-land, which is remark.ible for the fine crops of corn produced upon it, is, pro- 

 perly, the soil over the lowest beds of marly chalk, which are carried out upon the tops of the 

 projecting terraces; the term, " Malm-rock," being confined to the stony beds beneath. 



