Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/137

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LATER TERTIARY GEOLOGY OF EAST ANGLIA.
99

LATER TERTIARY GEOLOGY OF EAST ANGLIA. 9D Middle Glacial a thin bed of dark brown loam, which also fills a pothole excavated some 5 feet or thereabouts in that drift. After what we have observed as to the action of percolating water on the Red Crag, and especially the enwrapping of a prominence of Crag by bands of dark brown loam produced from the dissolution of the Crag ma- ° CD terial by the percolating water 3 3, (see section II.), we are far from 3 sure that the loam thus spread- p ing over the denuded surface g" and filling the pothole was ^ formed as a surface soil, and g the pothole excavated during J the interval represented by the |* denudation which we have been discussing ; and both the loam and pothole may be due only to IT percolation ; but we think that ST g * | p p *z o p QTQ Hi 1 -: ti H p tr ^§ =r ~ S* CD r T S P ^ /- g a- ^w £? 72 CD J-- P g | S-S «  ^ J. K' 3 ^ SI s r s p 2 2 3 £ P O Q. ►""• go <-r. »— J Go *r" s / ' » GO w. p a P on? -^ p OTQ 3 ct- 2 o ll QfQ PL p 5 a, I' p TO P - o P o ir 1 Pa 4 Jji 00 3' CD " 3" GO a ^c p p Pj 3 3* T3 p GO GO 5" Cfq O (KJ P ct- rt- 1= P

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CD O ri " £i 2- PL, P °3 !2{ S o p o P* .£? p i— 1«  I— 1 00 CO o O as no sign appeared of the sand g |~ J i^ itself following the loam into g- ' p^p the pothole, there is some pro- bability of this bed really repre- & senting an interglacial land sur- face. It is also worthy of no- tice that the interglacially de- nuded slope of the Contorted Drift is almost coincident with the postglacially re-excavated valley-slope. Having regard to the two lines of sections XVI. and XVII. across the Waveney at distant points, and to what we have described as to the pre- sence of the Middle Glacial along the valley-sides generally down to the edge of the sheet of Postglacial gravel which fills the valley-bottom in some parts (as for some miles on either side of Bungay), and to the edge of the alluvium sheet elsewhere, there seems to us no reason to doubt that the valley of the Waveney is of interglacial origin, like the other valleys of Norfolk which we have been describing, and like the valleys of Suffolk which we have presently to describe. The following hypothetical section (XIX.) represents what we believe to be the true, though concealed, structure of this valley. Q. J. G. S. No. 129. h