RECORD: Darwin, C. R. 11.1833. Geological diary: Monte Video (appendix). CUL-DAR32.83-84. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/).
REVISION HISTORY: Transcribed by Kees Rookmaaker, corrections and edited by John van Wyhe 6.2010, corrected against the manuscript by van Wyhe 7.2010. RN2
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. Where pencil was used instead this is noted in the textual notes. 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.
83A
[Hand drawn map]1
Harbor of Monte Video
Rat Isld
Lat. 34.55.20 S
Long 56.13.00 W
Var. 12.00 Easterly
Scale of Miles
1 Compare with the Rio notebook, p. 55b-56b. See Beagle notebooks, pp. 51-52.
'3.00' and '2.00' added pencil.
83
1833 November
M: Video (appendix)
On the road from the capital to Colonia del Sacramiento: we have at Las Pichas, besides the syenite, already described, some fine granite; here also is a relic of the modern bed described with all those of the same age on the coast of the Uruguay. — At St Jose fine granite in large crystals. — Old Rock
At Rozario. granite & gneiss the former in large crystals, silvery mica & what I have not noticed before garnets. —
At Colla I heard of marble. doubtless same as at Las Minas. Maldonado &c. — At Colonia there is much very fine grained siliceous, almost black gneiss (it somewhat resembles 1350 at Maldonado). — The cleavage runs E & W either vertical or almost so dipping to north. — To the Sierra St Juan some more of this rock is seen; at the latter place some quartz & gneiss. cleavage irregular N & S, & NE & SW. — The Islands in the mouth of then [Parag] Uruguay are generally granite (Fox). —
About 12 miles south of Mercedes on road to St. Jose much quartz, & from this about 14 miles all granite & gneiss. the former mica the Perdido, in immense blocks. — the cleavage generally W by N. & E by S. — in one place NW by W & SE by E. —
Limit of modern beds. I could see The modern beds extend to about Lat 33°. — how much further I know not. — at Salto, where there is waterfall there must be the old rocks. — But all this M: Bonpland1 has examined. — I have been informed, that a little to the northward of Lat 32°. in Entre Rios, near coast & by Uruguay there are low granite hills, which run in a N & S direction. — Here the soil is sandy. & directing water of streamlets clear. — (Mr Megget). —
Limit of modern beds] added pencil.
84
1833 November
M: Video (appendix)
We have seen in the Maldonado, that the ancient Limestones & Granites run up as least as far north as Lat 33°. — Mr Fox. writes to me that at Port Alegre (Lat 30°. "the prevailing rock. is white granite", now lying over which, a porphyry. (1485 1486) forms considerable hills. 1485. 1486 — Near to this is other variety (1482 ... 84) of Porphyry. 1482 .. 84 — Mr Fox states that the whole coast from P. Alepe to Rio Janeiro is mainly granite. —
84 verso
Laminae of quartz at M. Video certainly not metamorphic
[sketch]
Fissures
page in pencil.
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 25 September, 2022