OF THE TJPPEK CKETACEOUS IN AVE ST SUEEOLZ AND NOEPOLK. 567 



•Cherry Hinton in Cambridgeshire, but they pass up into a rock 

 ■which is much harder and lumpier than any part of the Lower Chalk 

 in Cambridgeshire. The overlying band of marl is doubtless the 

 attenuated representative of the zone of JBelemnitella plena, though 

 its aspect is considerably different from that of its typical develop- 

 ment. There is no clear separation into two layers, its upper surface 

 is not so clearly denned as in Cambridgeshire, and its total thickness 

 is very much less ; the only fossils we could find in it were Terebratula 

 semiglobosa and Rhynclionella plicatilis, the latter being abundant 

 and the same variety of that species which is characteristic of the 

 zone in Cambridgeshire and elsewhere. 



The valley between Whittington and Stoke Ferry possibly coin- 

 cides with a line of fault, for the ridge on the Stoke side, which 

 should be a continuation of the Whittington outcrop, consists of 

 Chalk-marl and Totternhoe Stone. The outcrop of the Melbourn 

 Bock appears to be thrown back to the eastward, and emerges from 

 under the alluvium near Oxborough, but little is seen of it for some 

 distance. In an old pit by the roadside, near the windmill north 

 of Oxborough Fen, we found lumps of hard yellowish chalk con- 

 taining Rhynclionella Cuvieri and Inoeeramus mytiloides, evidently 

 belonging to chalk not far above the Melbourn Rock. 



Thence there is a feature running northward along the border of 

 Barton Fen, and then westward to a pit about half a mile south of 

 Barton Bendish : here the base of the Melbourn Rock is again seen, 

 together with some 30 feet of the underlying chalk. At the north- 

 east corner the section is : — 



feet. 



Thin soil, with hard nodular chalk below weathered into rough 

 lumps 4 



Yellowish, gritty, rough, and nodular chalk, passing down into 

 whiter nodular chalk, which becomes soft and marly below 



Very hard, rough, white chalk (about 8 feet), passing down into 

 greyish-white chalk, which breaks into blocks with a smoother 

 fracture 12 



Talus below. 



The west end of the quarry is entirely in the greyish chalk, 

 which contains a hard rocky band ; it is thick-bedded, and has a 

 slight dip eastward. The marl band contained Rhynclionella plica- 

 tilis, as at Whittington. 



At Marham lime-kiln, two miles further north, there is a similar 

 section, showing about 5 feet of the Melbourn Rock overlying the 

 yellow marly band ; the rough white chalk below is so hard that it 

 stands out prominently in the weathered face and overhangs the 

 blocky greyish chalk into which its lower part passes. The yellow 

 band at the base of the rock consists, in the upper part, of loose, 

 yellow, rocky chalk, and in the lower of yellowish marly chalk 

 and grey marl. At the north end of the quarry there is a marked 

 band of hard nodular rock at the base of the hard white chalk ; but 

 this seems to disappear southwards. 



