190 Mr. S. V. Wood on the Red Crag 



absent. The portions of this band rich enough to work are 

 those resting on the clay, being the deeper parts of the channels 

 thus eroded through the older beach, the band becoming poorer 

 as it rises up the sloping sides formed of beach Crag. Many of 

 the sections of this fifth stage expose a thickness of not less than 

 20 feet of it ; and one near Sutton Hall (now open) is a furlong 

 and a half in length, and full of the most intricate false bedding. 

 An interesting illustration of one of these channels is afforded 

 by the pits at Foxhall and Bucklesham. (See Section A.) The 

 Pectunculus-hdoaA with nodules invariably underlies the fifth 

 stage only where that stage rests on the clay; when the stage 

 rises over the beach Crags, the nodule-band either becomes 

 feeble or disappears altogether. The Crag of the fifth stage 

 may always be detected at a glance, and distinguished from the 

 lower stages by its horizontal stratification and the contrast it 

 presents to the underlying beach stages. The Crag of the fifth 

 stage, however, does not resemble the genuine deposit underly- 

 ing the beach stages at Walton Naze by containing shells in 

 the state in which they died ; on the contrary, although mani- 

 festly water-deposited, the organic remains in it are as worn and 

 travelled in appearance as those in the beach stages, and show 

 their origin to have been mainly from the material of the older 

 beach stages through which the channels have been eroded. 

 While this seems to have been the mode of formation of the 

 fifth- stage Crag, that of the beach stages seems to have resulted 

 from a sea forcing itself backwards from the shore by the growth 

 of the beach that it heaped up, until, by a slight subsidence, 

 the sea, recovering its place, planed down the old beach into the 

 small thickness that we find the lowermost stages now present- 

 ing, and recommenced the process of beaching up and forcing 

 itself back. 



The fifth stage, south and west of Chillesford, is everywhere 

 divided from the overlying red sands hyaline of erosion, sometimes 

 very faint, but generally strongly marked, and often, like the surface 

 of the fourth stage where overlain only by the lower-Drift sands, 

 irregular and deeply cut in. At Chillesford, however, the fifth 

 stage (under which I could not detect the nodule-band) resting 

 upon a beach stage, passes up, without the slightest break or 

 line of erosion, into the micaceous sands and laminated clays 

 first noticed by Mr. Prestwich in 1849, and which have as their 

 characteristic fossil the Mya truncata in the position in which it 

 lived j and these sands and clays, again, pass up in other places 

 (as at Iken and Aldbro^), without a break, into the extensively 

 developed sands of the lower Drift. At Chillesford (and it is 

 here alone that I have been able distinctly to recognize it) we 

 have the unbroken passage upwards of the fifth-stage Red Crag 



