342 



PKOCEEDTNGS OF THE GEOLOGICAL SOCIETY. 



Bawdsey and Felixstow. Flat pieces of the thin limestone seams 

 of the Coralline Crag are common in the Red Crag around Tatting- 

 stone, where the same reef-like structure of the Coralline Crag is 

 shown at Park Farm (fig. 24) ; and I have found some small frag- 

 ments even in the Ked Crag at "Walton. 



Fig. 24. — Pit at Park Farm, Tattingstone, near Ipswich. 



a^. I jrT^ Coarse gravel. 



Oehreous sands with 

 seams of ironstone, 

 &c. 



Eed Crag. „ _ 

 12 feet. "^ ^ 





Crag with a few co- 

 prolites. 



Light-coloured Crag, 



=^^g^ - - Face of old cliff; 

 depth not shown. 



Another old Coralline-Crag reef forms the nucleus of the ridge of 

 hUls from Gedgrave and Orford to Iken and Aldborough. The Red 

 Crag abuts against its flanks, and its summit is capped by the 

 ChiUesford clay ; but although the Red Crag can be traced close up 

 to these hills, the cliff-line is nowhere exposed. At the same time 

 the erosion of the Coralline Crag adjacent to this old reef during the 

 Red-Crag period is seen in the section given in fig. 15. It is pro- 

 bably the littoral zone of an old shore connected with a higher part 

 of this reef or islet that is indicated by the illf?/a-bed of Mr. Fisher. 



Having described the Red Crag and ChiUesford series in their 

 typical and special area, and followed them as far as Aldborough, we 

 come to more debatable ground. Some geologists have referred the 

 crag at the Aldborough ballast-pit to the Norwich Crag, and others 

 to the Red Crag. The next sections, however, which are only two 

 miles further north, present far more definite characters. Their re- 

 lation to the Norwich type cannot be doubted ; and to that group they 

 have always been referred. It remains now to be seen whether there 

 are sufficient grounds for considering the Crag in the area north of 

 Aldborough to be newer than the Red-Crag series, or whether it is 

 to be considered a synchronous deposit, with differences of character 

 depending upon local conditions. 



We have already noticed three ridges of Coralline Crag — one at 

 Tattingstone, a second at Sutton, and a third extending from south 

 of Orford to Iken and Aldborough. The first two are small, and 

 the Red Crag wraps round them without any change of character. 

 The third is more important and makes a greater break in the Red 

 Crag, which nevertheless reappears on its eastern flank, although 



