RECORD: Darwin, C. R. Geological diary: Elevations on coast of Patagonia. CUL-DAR34.61-64. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Kees Rookmaaker, corrections and editing by John van Wyhe 3.2011. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. This document, part of the largest scientific document composed by Darwin during the voyage of the Beagle, is written mostly in ink. Marginal notes are here integrated into the text.

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.


61

1

From the Gallegos to Coy Inlet we have 3 to 400 cliffs. —

Somewhere not far North of this the 840 range commences which reaches to within 6 miles of R. S.Cruz: we then have the 350 250 plain (this winds up the old S. Cruz Straits). & After crossing the low land formed by the river, we again have 330 plain ([changsby] says 350? Capt King says 300 to 330). this extends to the point South of St Julian, & forms the 430 range at South of Harbor. — This increase of 80 feet does not render the continuity of this plain improbable because at S.Cruz. the 350 355 plain close to the 840. one attained an elevation of at least 470 feet:

We shall and this plain is here close to an elevated range of 950. — Whether the 950 & 840. belong to same series I cannot tell: such variations in depth of bottom might happen, but perhaps it is not probable: — the South Point of St Julians is low land 7 or 8 miles in length, level & about 90 or 100 feet above sea. — This is nearly the only low plain left on the coast, but as it exists it is probable that it formerly did extensively but have been eaten away. — (Some appearances at mouth of S. Cruz render this probable). — V. Sketch of King showing three sets of plains. — By bird Island, 20 miles to the Northward, we again have the 350 plain. & South of it a 590 one. (so that in the Port St Julian district four series may be considered to be

61 verso

Distinct regular elevations inimical to Lyells hypothesis

General interest of all the [faults]

[sketch]

( S. Cruz

Inland cliffs
A
B
sea

Part SB. with greater slope must be owing solely to gravel but the inclination of strata of S. Josephs — original dip from Andes. —

the line of dip is to the NW, (which I measured. — beautiful proof against tilt from Andes. —

62

(2)

to be present. at Watchmans C. excessive denudation hardly explains present — at Port Desire a 250 & 325 plains are present — which I believe indicate two elevations: (the 325 plain is doubtless same as 350 only a little more to the West has made it lower): there are evidences of the 100 foot elevation. — & perhaps of some such plain as the (590 one). — At C. Three Points (N of C. Blanco) there is an extensive 250 plain same as lower Port desire. — (extending into gulf of St George (N B. It appears to me the 330 & 250 are more certainly distinct than the 840 & 95-, because there I have not seen those in contact). —

In centre of Gulf of St George. — Tilly roads (& 8 2 & 1/2 miles distant C. Marques) is a plain 580 feet (same as St Bird Island 590). From this an ascending series was seen of steps till some reached an estimated elevation of 1200 feet. —

But the cliff showed no signs (as at 840 one of S. Cruz) of the lower one.

Yet at North end of gulf, [illeg] "South Cape" is 250 evidently same as "C. Three Points." Nearly same longitude but 130 miles to the South. — Also at Point of gulf "W Creek Peak" the cliffs are 330 — very same as at Port Desire: —

At P. Lonos the estimated 1200 foot range is seen. —

About 15 miles to the North of this. P. Delgada is range of 200 (probably 250 sinking as will be shown to occur to the North. —

At Engano Bay. extensive plain 350 ft. —

Also at this place, plain 6 miles long only 60 feet high; perhaps same as 100 ft to South

62v [blank]

63

(3d)

All about new Bay. from many measurements Plains vary from 200 to 260 — Perhaps from 220 to 240 will very truly represent them, the same holds good to S. Joseph & the R. Negro-sandstones (from many measurements & aestimations). — At new Bay there are some plains estimated beneath 100 — probably same as Engano 60 ft one). — At the Fort in St Matthias in this 230 great range some insulated ones occur of 380 & 400 ft. — It is difficult owing to distance & more twisting to know what series to attribute these to. — This applies to all the following ones. —

At B. Blanca I estimated main plain 200 ft — (there were obscure indications of lower ones). Mt Hermoso is 120 & there is a lower one of 40 & ever perhaps another for P. Alta. —

The plains north of this may perhaps be represented by the 120 170 ft plain South of C. Corrientes. —

At B. Ayres the plains are about 40 ft & this range extends for a great distance up the Parana: it is ossiferous. so is the least elevation on the coast of Pat. (100 ft plain at P. St. Julian. —

(NB) The three or four lines of sand dunes behind anchorage at B. Blanca. prove same thing.

63v [blank]

64

(4)

I think the foregoing notes prove pretty satisfactorily that there have been 9 or 8 7 or 8 elevations on the coast of Patagonia. — Probably more. —

Perhaps S. Cruz require one between (350-460) & 580 —

The 350 elevation seems very distinct it can be traced for about 550 miles in a N & S line very distinctly, & certainly some way up river at S. Cruz.

 

owing to hard rocks?

both to suffer extra force:

1200 Aestimate
— ?
950
840
710 ??
580
350
250
100
60 to 40
Entire. denudation

710
463
247

The 1200 cliffs not recurring about S. Cruz

cannot be counted because it may be 950 with greater violence

 

The 250 can be traced for even more. about 600 miles: —

The 40 can be distinctly traced for about 250. — if Including Pampas: how much?.

I am inclined to think the whole coast rose I altogether for 1200 or 1800 miles: that the 200 cliffs of T. del F. rose with the 350 or [illeg] 250 cliffs or 350 with the surface of which they are contemporaneous [illeg]. — (deposited in a shoaler? sea). —

(Number of elevations proved in valley of S. Cruz nr beneath the height of any cliff. —

All the elevations beneath 350. have been taken place since recent shells (& probably judging from river one before that

The immense extent of elevation is argument against Mr Lyells theory of protrusion of igneous rocks beneath the surface.

owing to hard rocks...greater violence] in margin.

64 verso

Elevations on Coast of Patagonia

South of S Cruz Straits from St Julian to S. Cruz

Valleys at S. Cruz

How formed? sea or diluvial wave?—

two or three lines in faint pencil are illegible on the microfilm.


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

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