124 R. M. Bnjdone — Further Notes on the Trimmingham Chalk. 



now within the Arctic circle glaciers have streams of running water 

 issuing from their fronts ; there must have been, therefore, very 

 great erosion in the glacier valleys by running water during the 

 maximum glaciation, and the valleys became rapidly deepened. 

 When the climate became severer and the glaciers became smaller 

 owing to insufficiency of supply, they no longer flowed down the 

 valley as it originally existed, but in the narrower gorges excavated 

 by the sub-glacial streams in earlier times. This fact, that during 

 maximum glaciation there was necessarily a milder climate and 

 consequent greater melting and erosion, may perhaps explain how 

 glacier valleys in Europe and America have been scored by ice from 

 their bottoms to heights of 3,000 and 4,000 feet above. To maintain 

 that such valleys at one time were filled from top to bottom with ice 

 is, to my mind, equivalent to saying that in an ordinary river valley, 

 with terraces high up the sides, the valley was once filled with 

 water from the present level to the topmost water-mark. 



VI. — Further Notes on the Stratigraphy and Fauna of the 

 Trimmingham Chalk. 

 By R. M. Brydoxe, F.G.S. 

 (PLATES YIII AXD IX.) 

 {Concluded from the February Number, p. 78.) 

 rpHE very uniform trend of all these ridges will have been noted, 

 J_ but my previous remarks on the general strike of the foreshore 

 chalk require considerable modification. The whole of the chalk so 

 far exposed may be divided into four sections. Each of these 

 comprises an exposure in or close to the cliff of what appears to be 

 the highest part of a ridge running down the beach in a direction 

 from 10° to 30° south of east (and sinking as it goes) to about the 

 half-tide level. Here thi-ee of them (the exception being the 

 brickfield chalk) turn and run for some way roughly parallel to 

 the shoreline, and then resume their original direction and run out 

 to sea. The brickfield chalk only varies from this plan by running 

 out to sea with practically no change of direction on the way. 

 Except where a ridge is running up to the cliff, the substratum of 

 the beach is invariably glacial clay down to about half-tide level. 

 Here it is either banked against what appear to be vertical faces of 

 chalk or else {between the foreshore exposures) disappears under the 

 sand. It has never been seen to run out to sea, and every time 

 a fresh bit of the foreshore below the half-tide level is cleared 

 of sand it is chalk that is revealed. In the case of the section 

 attached to the north bluff there is below the half-tide level a 

 continuous mass of chalk with perfectly regular bedding exposed 

 for at least 1,000 yards along the shore, and directly opposite the 

 north bluff I have myself seen chalk continuous from the foot of the 

 bluff for over 200 yards straight out to sea (except about 20 yards 

 close up to the bluff, which, however, are covered by Mr. B. B. 

 Woodward's letter in the October (1905) number of the Geological 

 Magazine), the regular sequence of the beds being only broken by 



