21 



1868, The Roslyn or Rosswell Hill Clay-pit is the subject 

 of a communication from the Rev. O. Fisher, Camh. Phil. Soc. 

 and Geol. Mag. Vol. v. p. 407, in which he dissents from 

 Mr Seeley's mode of accounting for the presence of the Creta- 

 ceous beds, and considers them to form a Boulder-like mass in 

 the Glacial Clay, similar to those in the cliffs near Cromer. He 

 gives a ground plan of the pit and notices that at the western 

 end, the chalk thins out and the Boulder Clay passes beneath 

 it. He believes the hollow to be a trough ploughed out of the 

 Kimmeridge Clay and the mass now occupying it to have been 

 dropped by an iceberg. The slickenside surfaces "only occur in 

 recent slips of the Boulder Clay and not along the junction 

 between the two clays;" he therefore concludes that the evidence 

 in the pit is against any theory of faulting, though he acutely 

 observes that if the country were mapped and a fault affecting 

 other strata traced through the pit this would settle the ques- 

 tion in its favour. In the same volume of the Geological 

 Magazine these views of Mr Fisher are criticised by Mr Seeley 

 and the "Boulder hypothesis" is scornfully rejected. Mr Seeley 

 conceives the facts to prove (1) that there is a sequence from 

 Chalk to Kimmeridge Clay, (2) that the sands under the Gault 

 may be connected with those outside, above the pit, (3) that 

 indubitable slickenside occurred in the junction between the 

 Boulder Clay and the Cretaceous beds figured in Geol. Mag. il. 

 p. 532. He adheres to his previous statements and conclusions 

 regarding the faulting of the strata. 



1871. In a paper "On Phenomena connected with Denuda- 

 tion, observed in the Coprolite pits near HaslingfieldV' Mr 

 Fisher describes the sections then observable ; in these the 

 upper portion exhibited a variable thickness of soil containing 

 land shells, to which he gives Mr Trimmer's name of "Warp." 



Below this is found the disturbed soil which Mr Fisher has 

 elsewhere denominated by the name of "Trail" (see Q. J. G. S. 

 Vol. XXII. p. 553) : this he describes as sometimes little else 

 than disturbed clunch with occasional pebbles and boulders, 

 but at other times containing patches of clayey gi-avel and 

 sand. In accounting for the presence of this "Trail," he rejects 

 as inapplicable the agency of rivers, admits that it may possibly 



^ Geological Magazine, Vol. vm. p. 65. 



