Dr. Wright on the Geology of the Isle of Wight. 17 



The transition from the lower freshwater to the ".PP"' marine 

 is made bv a series of beds contammg estuary species and the 

 «e from the marine to the upper freshwater is m hke man- 

 Te Se by several zones of estuary shells Tji-ss-aU^^^^^^ 

 the eenera in the manner described is very decided. 1 leel satis- 

 fied that the contrary opinion has arisen from observers having 

 collected specimens from the foundered beds on the shore mstead 



of from the strata in situ. . i o +n fi° 



The beds rise very uniformly at angles varying fiom 1 to & 

 to the ho'Son, and incline to the east. Their continuity is mter- 

 runted by four chines and one ravine : commencing from the 

 noS and proceeding southwards are the followmg chmes Lyn- 

 Chen Brainble, Colwell, and Weston. The ravine separates the 



ti series at Alum Bay from the lowex;^-^-*- ^ ^J shT 

 this o-orge a pathway leads from the rabbit warren to the shoie. 

 Thelfnes L forLd by streamlets whose Yf!Ve\ScT 

 course to the sea have cut down the clays and marls to the beach. 



The observer is supposed to walk from Sconce to ColweU and 

 ToUands Bays along the shore, thence round Headon Hill to 

 Sum Bay? and to study the beds as they rise from the shore and 



^Th^rtlXF^taining to the upper freshwater formatK>n 

 around Sconce Point have experienced much disturbance and aie 

 Ta Ite of ruin. The hill forms an uneven « Y'ri^Hts 

 rent by the breaking up of the clays and marls of which it is 

 composed; it is covered with grass and foliage almost to the 



""trom some blocks of hmestone near the shore I obtained Bu- 

 limus ellivticus, Paludina angulosa, and Planorbis. 



Thes fossils are denuded of their shell. The clays and mar s 

 that form the upper part of the hill above he Coast-guard sta- 

 tion Ssconce pLt contain freshwater shells m a fragmentary 



'^n';. 1. The first bed in situ is a band of blue clay which rises 

 on the shore at a point nearly opposite to Hurst Castle and 

 where Worsley's Tower formerly stood. It exhibits many shelly 

 lamina. Potamomya plana is in great profusion in this bed. 

 It rests upon slate-brown, rusty, and variously coloured days 

 in which Paludina, Cyclas, Potamomya lie m zones It ^^ "^clmed 

 at an angle of about 3°, and measures about 15 feet. The ine 

 of elevation has been much disturbed, and the angles which the 

 bed makes are various at different points; it disappears south ot 



^^No"^2^'l regard as a brackish water series. It consists of 

 Ann. ^ Mag. N. Hist. Scr. 3. Vol. vu. ^ 



