WCP2475

[1]

24^th Oct. 1983

Dear Sir

I have read your article with the livelist[sic] interest. Your argument as to the sub[MS illeg.] ^{of superficial [MS illeg.]} contours[?] of the lake basin is, so far as I know[?], quite original, and is certainly most convincing. I don’t see how the [2 words illeg.] glacial erosion can wriggle out of it!

I am not so sure of the old "allurium" underneath the aluvial[?] [3 words illeg.] being a [2 words illeg.]. The "allurium" consists chiefly of gravel[?] & shingle[?], and seems to me to be of the same character and origin[?] as the gravels[?] which underly[?] the boulder clay and morraines[?] opposite the [MS illeg.] ends[?] of all the great[?] Alpine lakes. My one[?] the [MS illeg.] which were[?] swept out from underneath the [MS illleg.] glacier[?] and are then of flurio[?] [MS illeg.] origin [2] is improbable. I think that any periglacial[?] allurium could have been preserved in such positions. The glacial deposits that [MS illeg.] the particular allurium in question are those belonging to the latent great[?] entrance[?] of the glaciers. Even if it could be shown that the [MS illeg.] deposits returned[?] to vally[?] [MS illeg.] to the earlier epoch of greatest[?] glacier[MSilleg.] — still that would [MS illeg.] that the underlying alluvial gravels[?] [MS illeg.] of [MS illeg.] glacial age[?] and [3 words illeg.] accumulation. Gravels have always opened out in [MS illeg.] of the glaciers. [MS illeg.] when a glacier came to occupy the basin of Lake Geneva[?], gravels, swept out from the [2 words illeg.] be distributed over the [MS illeg.] grounds in front of the ice.

This, however is a [MS illeg.] small point and does not weather in any way your general arguments.

[3] I was much obliged to you for your [MS illeg.] letter in which you remark upon the thickness of the Palaeo[MS illeg.] deposits being [MS illeg.] on evidence [3 words illeg.] of depression of[?] the land. Of course I don’t maintain that a thickness of 10,000 or 20,000 feet[?] of shallow waters [MS illeg.] indicate[?] gradual[?] depression to that extent. Doubtless [MS illeg.] sediments were laid down in shallow water, and finer sediments accumulated contemp[MS illeg.] in deeper water. But I doubt whether the composition[?] in Palae[MS illeg.] times have on all [2 words illeg.] shut we have [MS illeg.] the earlier Palae[MS illeg.] afford no evidence whatever of deep water conditions—nothing comparable[?] to what we have now.—Unless[?] we take the radi[MS illeg.] chart[?] beds [2 words illeg.] in our Lower Silurian in Southend as evidence of deep-sea conditions. It is the [2 words illeg.] occupied by the older[?] Palae[MS illeg.] strata and the [MS illeg.] thickness which they [MS illeg.] over wide regions[?] that [MS illeg.] one to [MS illeg.] that they have been accumulated over in shallow seas upon a gradually sinking floor. But enough!

I see [2 words illeg.] in your papers to Stellands[?] [MS illeg.] in to the glacial[?] erosion of [MS illeg.]. I can give you several similar [MS illeg.] made by Penck. [MS illeg.] & others as to the glacial[?] erosion of the alps. But the one you [MS illeg.] is probably efficient for your purpose.

Believe me | yours very truly | James [MS illeg.]

Kind regards[?] to my cousin[?] when next you see him?

[4] PS. There is another point in your paper [2 words illeg.] will excuse me if I [2 words illeg.] on [2 words illeg.] from [MS illeg.] that this is [2 words illeg.] why [MS illeg.] accumulations underneath a glacier should be eroded. It is quite true that they would not be ground down & [MS illeg.] as if they were hard rock. But we have evidence &[?] shows that corse[?] materials were marked[?] and dropped [MS illeg.] underneath ice. This in some places one sees beds[?] of gravel[?] [MS illeg.] & clay thrown[?] into the wildest confusion—contorted[?] [MS illeg.]—and the boulder-clay forced into them. [MS illeg.] [a sketch depicting the above appears here] one may note has considerable thickness and the [MS illeg.] deposits have been dropped out of place and gradually incorporated with the ground[MS illeg.]. Great[?] [3 words illeg.] beds (Brown Coral beds) in [MS illeg.] have been forcibly dropped [5] [MS illeg.] and became enclosed in [MS illeg.] & the like has happened with [3 words illeg.] in the Alpine groundmorraines[?] one sees [MS illeg.] block (which could only [MS illeg.] come from the bed of the glacier), so that one is compelled to believe that glaciers not only grind and abrade [2 words illeg.] dislocate & displace rocks. The recurrence[?] of [MS illeg.] ground etc. underneath the terminal fronts[?] of a glacier is as everyone knows common enough. But towards its terminal end the ice [MS illeg.] to its diminished thickness and a much diminished rate of flow has ceased either to erode or drag. All this you know quite well, but if some [MS illeg.] be not made to it, some one will be sure to call collection of it—and it is better perhaps to [MS illeg.] him!