The Chatty and other Clays of Eastern England. 463 



Clay debris upon Kimeridge Clay and Oxford Clay detritus upon 

 Oxford Clay. The clay is dark-blue on Kimeridge Clay, and 

 light upon the light-blue Oxford Clay, besides which the fossils in 

 the clay show a large percentage of Kimeridge Clay species where 

 that rock lies below, and of Oxford Clay fossils where that is the 

 subjacent bed. Not only so, but we find that the Kimeridge 

 Chalky Clay invades the outcrop of the Oxford Chalky Clay, and the 

 latter does not come on until the Oxford Clay has fairly taken the 

 ground. In like manner the Boulder-clay is much more chalky 

 on the Chalk than elsewhere, and this feature it maintains over 

 the narrow Greensand outcrop, on to the Kimeridge Clay, as at 

 Mareham, where chalky Boulder-clay is burned for lime. It is 

 quite impossible, as Skertchly says, that icebergs should have 

 dropped their burdens so geologically. (" Geology of the Fenland," 

 pp. 215, 216.) The iceberg theory has, so far as I know, no friends 

 left. I have already, in another paper, criticized the shore-ice 

 theory, of which Mr. M. Reade has been the champion. He has 

 invoked it to explain the portage of the vast blocks which so 

 often occur in the Chalky Clay ; but he would hardly attribute 

 to coast-ice the collecting of the materials of the Chalky Clay, the 

 mingling of them into the present medley, and the distribution of 

 the mixture far and wide over one-third of England. 



"Whichever way the problem is approached, the intervention of 

 ice as a catisa causans seems impossible. It was appealed to in 

 reality to explain phenomena whose explanation is to be sought 

 for in very different causes — (1) the scratching of certain chalk 

 masses, a result which must have followed from any theory of the 

 distribution of the Chalk involving its portage from one place to 

 another, which we all concede ; (2) the presence in the eastern drifts 

 of vast continuous masses of chalk, etc., which, as we have seen, is 

 due to an entirely different cause; and, lastly, the presence of the 

 foreign boulders. This last fact I hope to discuss on another 

 occasion, when I should like to correlate with the clays we have 

 been discussing the gravels and so-called Middle Sands of Eastern 

 England, in which these foreign stones also occur. In the mean- 

 time the view I would press is, that these clays present no single 

 feature consistent with their having been deposited by ice, nor do 

 I know of any reason which is sound for invoking ice to explain 

 them. The view is held by others besides myself, on other grounds. 

 Thus, Mr. (now Professor) Seeley says: — "1 have not found in this 

 locality a vestige of iceberg action. Of glacier action the deposits 

 of the Fenlands offer no traces, unless the fragments of northern 

 rocks be held to prove that one great glacier stretched from the 

 Tweed to the Thames, of which there may be as much likelihood as 

 that the ice of the Caucasus excavated the Black Sea." (Geol. Mag., 

 1866, Vol. III. p. 496.) Mr. Jukes-Browne's opinion I have already 

 quoted, but the most unexpected and trenchant view of all is that of 

 the late Professor Carvill Lewis, who was one of the archpriests 

 of Ultra-Glacialism, and who in regard to East Anglia emphatically 

 took the same side. 



