RECORD: Darwin, C. R. Geological diary: Appendix to 27th / The Clay yellowish in lower plain is part of main plain. (7.1835) CUL-DAR37.704-708 Transcribed by Kees Rookmaaker, edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Kees Rookmaaker, edited by John van Wyhe 10.2012-3.2013, 2015. RN2

NOTE: This document, part of the largest scientific document composed by Darwin during the voyage of the Beagle, is written mostly in ink. Where pencil was used instead this is noted in the textual notes. Marginal notes are here integrated into the text.

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Reproduced with the permission of the Syndics of Cambridge University Library and William Huxley Darwin.

See the introduction to the Geological Diary by Gordon Chancellor.


704

Appendix to 27th

The clay, yellowish in lower plain is part of main plain. — The mass of coarse granitic shingle takes up about 1/3 of cliff where highest, interstratified in curves with fine sediment. — The upper level plain certainly forms a sort of Escarpement on Bellavista plain, but must blend with it on road to Lima. —

[sketch] black

The plain is not absolutely level, rises from about 70 feet, where the appearance is complete. Yet the cliff a mile or two further on cliff is about 120 ft high. — it then rather again fell & in distance again rises appears quite level. —

Whole surface & inland, bits of old shells, even where 120, also then at least 6 ft of the earth, with bits of tiles, occasional minute pebbles, coarse horizontal arrangement. —

704 verso

Tiles not thought in Lima Indian.

All bits of thin [illeg] large earthen vessels. —

They abound in groups, as if large cart full broken.

How are the dead buried. — Shells nearly all broken. — occasional stone as large as 2 fists. — [sketch] pebbles apparently a double pavement. resting on thin layer of sand with a shell or two (probably alluvium or plain.) covered with the 3 feet of mud &c &c. —

In so the plain are rounded mounds as if heaps of mud, had resisted the levelling power of water & only been modelled. about 20 ft. high several in number, so soft materials. that they could not have resisted long the action of water, plain abuts up level to their base:

I imagine, that a low sterile plain with Indian burial ground. (for bones

705

arrangements of coloured strata of clay beds thinning out & covered. — some layers bright red: the earthy Tosca rock very irregular form lowest. Some calcereous layer. & numerous & then might be decayed & scarcity of other remains explained (although in time of Indians not so many present). — subsided, sea burst over it, mingling shells, pebbles, earthen ware vessels in stratum (Possibly lake, old shells on surface: no) remained for time sufficient to lever surface, distributing alluvium equally excepting a few points. — Subsequent elevation raised this & formed a spot, for a Harbor, which occupied site of Bellavista.

This amount of elevation agrees with S. Lorenzo. — It would appear, that this land had from a sot before. overflow. because sides of Escarpement are thicker covered than top, what might well happen. —

At base of Escarpement, from a black base, there would appear to have been two distinct.

705 verso

overflow, pushing the upper at 46.

The surface of the inferior clay, so very much cut up. — Certainly from some appearances a great flood coming over the country charged with mud & not by stones & shells. would account for such wide level plain. — Anyhow, there is interest in so extensive a commotion, however it may have occurred. with man's time. — The cliffs extend continuously for about 8 miles. I only examined from 2 — to 3, a little way inland. — I have no reason to suppose that the covering of the higher part, does not extend still further.

706

July 27th

walked to South beach — tremendous breaker, muddy [illeg]. roar of pebbles. — regular mile. — night & day, year after year

Flat plain covered with soil, slopes up (to seaward) (V Chart of Bellavista) in an irregular escarpement to another very level plain: an escarpement about 12 feet high base yellowish clay, with roots & foot of black mould covered by irregular bed of mud, bits of tiles & horses teeth. recent sea shells several feet thick, probably from great earthquake. — But The upper plain is compared slopes very gradually a little towards inland escarpement (for it is a point between sea cliff & plain of Bellevista), when attains full height of perhaps 100 ft high, when a is composed of bands of yellowish & reddish clays & sandstones, sometimes one character, sometimes other prevalent very fine grained. — Must have been stratified mud. — with central structure of course shingle resting on clayey beds. —

[page 707 appears absent in the sequence]

708

This narrow level plain is covered with stratum about yard thick of pale mud. — upper part vegetable stain. — full of broken recent shells & pieces of red earthenware:

By the linear arrangement in some parts of mass & general appearance & level surface & think it is certainly an aqueous deposit (certainly from sea-shells is). But not at bottom of sea — because rows of rounded stones placed as children do, on base of walls. 2 feet deep in this substance.

Therefore alluvial covering — no bones ∴ probably Indians. — too high for 1846 earthquake, as above, Bellavista.

A low plain at times probably near the sea. — sea occupying plain of Bellavista, main bed of tiles about 70 ft above sea. —

Callao, old & new on same level. Could sink. Callao scarcely anything without inundation protected by shingle bank. —

plain probably composed of mud. —

708 verso

The Huacas or Bellavista appear some artificial; but generally heaps of shingle artificially faced & [superadded] to — contain pieces of Pottery precisely similar to those on plain.

These are the hills of Alluvium mentioned — They may have extended previously to the deposition of plain, but I think subsequently.

[sketch]


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Citation: John van Wyhe, editor. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

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