HEADON BEDS. 



131 



Lower Headori 

 Beds. 



f Green clays with thick bands of Pota- Ft. In. 

 f momya plana. Paludina in places, 

 I Selenite .... 



I White sands, without fossils 

 I Thin band of sandy limestone with 

 I Planorbis, &c. - - . 



I White clayey band. No fossils 

 I White sand .... 

 <( Green marls with lignite bands. Broken 

 I Cyrena and Potamomya, Cerithium 

 I elegans ? C. duplex! - - - 3 



Pink and yellow rather compact sands, 



with a lignite band at the toj) - 2 6 



Ferruginous ledge of dark-red sandy 

 beds, with a strong but narrow iron- 

 band at the base. No fossils - - 2 

 __ White sands (Headon Hill Sands). 



The Headon Beds vary so much in short distances that other 

 measurements, made only a mile or two from Headon Hill give 

 very different results, though the total thickness is nearly the 

 same. The following were taken about 1852 by E. Forbes and 

 H. W. Bristow :— 



Section of the Headon Beds in Colwell and Totland Bays. 



Upper Headon 

 Beds, 47A 

 feet. 



Dark blue clays alternating with ferruginous 

 and septarian bands. Paludina lenta, P. 

 globuloides, Limneea longiscata, Serpula, 

 Potamomya gregaria . . . 



Red and green marls ... 



Sandy beds, greenish clays, and grey shales, 

 with lenticular patches of broken shells and 

 wood. Paludina lenta above, Potamomya ? 

 Cyrena obovata, \ar. major, fi'agments of 

 Unio, Melanopsis fusiformis ? and Melania 

 muricata - . - - - 



White, yellowish, and dark sand, Nvith clayey 

 streaks. Melanopsis fusiformis, M. subcari' 

 nata ? Cyrena pulchra. Lenticular patches 

 of dead Melanopsis and Cyrena obovata in 

 the lower part .... 



Limestone. Limncea longiscata, Planorbis - 



Greenish clay and sand, crowded in places 

 with univalve and bivalve shells. A ferru- 

 ginous band at 10 inches from the bottom, 

 of the bed. Poiamides trizonatum, Cyrena 

 obovata . . - - 



Argillaceous limestone, passing southward 

 into a bed of sand. A carbonaceous band 

 occurs at the base. Paludina angulosa, 

 Liimncea longiscata, L. subquadrata ?, L. 

 angusta?, L. arenularia?, L. tenuis?, 

 Planorbis euomphalus, P. rotundatus, P. 

 obtusus, P. lens, P. platystoma, Nematura. 

 (This bed occu])ies the foreshore at ClifF 

 End Fort) - - - - 



Bluish-yellow and purplish laminated sands 

 and carbonaceous shales (under the battery, 

 southern end) - 



Laminated clay and sand, with ferrugmous 

 sandy lenticular patches and lines of Pota- 

 momya in places. Potamomya 



Ft. In. 



6 

 1 



8 6 



5 

 1 



- 10 



3 



10 



3 



I 2 



