6 Geology. 



the Oolitic and Trias " : or, in other words, beds of the former age 

 had never been seen to rest directly on those of the latter, Liassic 

 beds everywhere coming in between the two. 



Against the suggestion " that rocks of the Old Red Sandstone and 

 Devonian type are not likely to occur near together," Mr. H. B. 

 Woodward says that it is " opposed to what is well known in 

 Devonshire," where sandstones and grits occur " nowhere far 

 removed, geographically, from rocks of the Eifelian type. ... 

 Hence, without committing myself to any definite opinion on the 

 subject, there appears to me no reason why rocks of Old Red 

 Sandstone type ... should not occur, as well as Devonian strata, 

 under the London Basin." (4) In 1886 appeared a full description 

 of some Kentish deep borings (5), which was accompanied by some 

 " General Remarks on the Deep-seated Geology of the London 

 Basin " (pp. 40-44), in which it was said, of Prof. Hughes' argument 

 against the Triassic age of the red beds, noticed above, " that it 

 applies only to the Richmond section, where the red beds are 

 overlain by a Jurassic deposit. It does not apply to the cases of 

 Kentish Town and Crossness, where the Gault comes next to the 

 red beds. As, in the West of England, Cretaceous beds, over- 

 lapping the whole of the Jurassic Series (including the Lias), often 

 rest at once on the Trias, so that a like thing may occur in the 

 London Basin "... 



Sir J. Prestwich (6) describes the red beds at Crossness as 

 " mottled red grey and greenish hard sandstones and red, slightly 

 calcareous clays " ; and continues : " but owing to the small size 

 of the borehole, the specimens were so fragmentary and, as in the 

 case at Kentish Town, so much mixed with debris and fossils from 

 the Gault and Chalk, that their determination was for a time 

 difficult. After however inspecting various specimens . . . and 

 eliminating all the sources of error, I have no doubt of the identity 

 of the beds with those at Kentish Town," which, as we have 

 seen, he considered Old Red. Dr. C. Barrois concluded, from 

 specimens, that these rocks were Triassic. No boring has passed 

 through to the base of the red rocks, so that what may underlie 

 them is merely a matter of supposition ; in all the borings showing 

 Carboniferous or older beds they have been absent, and it remains 

 for them to be found either above or below the Carboniferous 

 Series to satisfactorily settle the question of age. 



With the dismissal of the Red Rocks not much remains except 

 to note the remarkable absence of the Lower Greensand, which 

 absence could never have been suspected, the Gault clay proving 

 to be the youngest bed to cross the Palaeozoic Ridge. Most of the 



(4) Geol. Mag., dec. iii., Vol. III., p. 43 (1880). 



(5) Quart. Journ. Geol. Soc., Vol. XLIT. 



(6) Quart. Journ. Geol. Soc., Vol. XXXIV., p. COS (1873). 



