RECORD: Darwin, C. R. Geological diary: very strongly: this elevation probably choked up C. Negro Isthmus. [1834] CUL-DAR34.197-198 Transcribed by Kees Rookmaaker, edited by John van Wyhe (Darwin Online,

REVISION HISTORY: Transcribed by Kees Rookmaaker, corrections and editing by John van Wyhe 4.2011. RN1

NOTE: 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.

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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.



very strongly: this elevation probably choked up C. Negro Isthmus (same height with Elizabeth Island?)

Currents through the mountains being choked render this more probable. (anyhow it was an old channel & is now closed): The (N part) Sts of Magellan being drained by St Sebastian were not traversed by the main stream: hence the land allued was joined. —

Otherwise it must be a very great upheaval to choke up a channel when streams cut out deep channel. (in narrowest 62 fathoms). — Animals passed over; the currents eat a passage through from the S. Bay: (Proofs of inland bays. consuming cliffs). — X

197 verso

X. Fresh elevations raised land present height. —


How far are these lines of deposition in the coarsest part of beds in St of Magellan? —



The advantage of this hypothesis is leaving the narrows always a channel. — for if they had once been joined, it is difficult to imagine the sea. could have eaten a passage: the sea can only, when guided by a valley eat in a large curvature: which makes the explanation 2. narrow difficult. — It would be wrong for the sake of hypothesis to neglect evidence of animals & correspondence of cliffs. —

198 verso

Elevations probably took place when. the 350 or 250 plain oozes from the sea. if the former, the sea must have been shallower than the coast of Pat; which is not probable: — Anyhow the anterior beds having been removed by strong currents through passages in the mountains: these were deposited at some epoch period

soil & some shells soon distributed over the gravel. —

T. del alluvium & high central alluvium of different ages —

Braker N 1620   Orozee, south later 970  
  S 1397   Sebastian C. 190  
Double Hill St Sebastian 290   do. 9 hill 950  
Elizabeth Isd 150        
Esp Santo 182        
H. Cliff S of do 250   E of C. Forward +/256 (1536)
C. Negro 160   SE of d W. Bay +/115 690
Narrow (1) S. Seb 120   down to P. St. Ann 110 - bottom 660
Orange Point 210        
High land s. of do (607)        

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Citation: John van Wyhe, editor. 2002-. The Complete Work of Charles Darwin Online. (

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