On the Age of the Norfolk Forest bed. 267 



numerous intervening places. It is a divisional liae tliat for many 

 reasons, in my opinion, marks the boundary between the Pliocene 

 beds and the Drift or Glacial formations. 



Much black peat and compressed wood occasionally occur in places 

 along this horizon ; sometimes immediately lying on the surface of the 

 rootlet-bed, at others lying in basia-shaped hollows scooped out of this 

 same deposit, which in places contains freshwater shells and fresh- 

 water beds associated with it, such as the well-known Z7«/o-beds, etc. 

 Drifted wood and other vegetable matter occasionally occur in the 

 formations above and below this line, in considerable quantities in 

 certain localities, as at Bacton and elsewhere. 



Again, Mammalian remains are to be found in abundance in this 

 rootlet-bed, in some of its associated freshwater black-beds, and 

 in the beds underlying, down to the chalk, but never (or hardly ever 

 — never so far as my actual observations have gone) in any of the 

 Bure Yalley beds overlying. A few have been recorded as having 

 been found at the base of the Bure Yalley beds in some inland pit- 

 sections around J^orwich and other parts, immediately overlying the 

 denuded surface of the Chillesford clay. These may have been 

 derived from the beds beneath, or the denuded rootlet-bed, if it ever 

 extended so far inland. However, the rule is, to find them where 

 I have stated, and previous searchers and writers corroborate my 

 investigations and remarks in this respect. To speak generally, this 

 divisional line, which I consider marks the top of the Pliocene beds, 

 occurs about midway between the base of the Cromer-Till (which, as 

 a rule, is a very marked line) and the Chalk, or, more strictly speaking, 

 a little nearer to the Chalk ; and inasmuch as the greatest thickness 

 of the beds between the Cromer-Till and the Chalk is seldom so much, 

 and nowhere more than from about 26 to 30 feet (which is about the 

 maximum thickness of them in some places in the neighbourhood of 

 8herringham and Eunton), the Pliocene beds, or what remains of 

 them, are conseqaently but about 13 to 15 feet in thickness, and 

 rarely to be seen so much as that 



The nature of this rootlet-bed can be best studied at Kessingland, 

 where it is well developed, and generally more or less exposed. It 

 mostly consists of a stiff clay of a greenish-grey colour, sometimes 

 mottled with brown; it contains white concretions ("race"), many 

 scattered little black flints, and in places numerous mammalian 

 remains, scattered throughout its mass, and averages from about 4 to 

 10 feet in thickness, sometimes forming a distinct homogeneous bed 

 of clay, and sometimes containing indications of stratification with 

 sand; thousands of rootlets have been observed by myself in it, in 

 a vertical position as they grew 



The relation of this rootlet-bed to the beds beneath it is of especial 

 interest, and can be best studied at the extreme ends, viz. at Kessing- 

 land and "Weybourne, where the lower beds rise up. We will first 

 deal with the Kessingiand end. During my researches there, I have 

 seen the extreme southern part of the cliff from the road to the 

 flagstaff well exposed, that portion usually being hid by talus and 

 blown-sand. The section exhibited was the rootlet-bed 4 feet in 

 thickness, underlaid by 2 or 3 feet of buff-coloui-ed pebbly sand, and 



