The Last Glaciation in Central Magellan Strait, Southernmost Chile

Chalmers M. Clapperton, David E. Sugden, Darrell S Kaufman, Robert D. McCulloch

Research output: Contribution to journalArticle

117 Citations (Scopus)

Abstract

Glacial landforms and drift stratigraphy in central Magellan Strait, southernmost Chile, document repeated fluctuations during the last glacial cycle of outlet lobes from an ice cap centered over the southern Andes. The lobes developed comparatively low-gradient profiles because of low basal shear stresses over soft deformable beds and this made them sensitive to even small-scale changes in the mass balance. Such low profiles and rapid calving in deep proglacial lakes during deglaciation may have made the Magellan ice lobe particularly responsive to climatic fluctuations during the last glacial cycle, and to advance and retreat over considerable distances. Study of the glacial landforms and drift stratigraphy has led to the identification of at least five glacier advances to limits at and south of the Segunda Angostura. Fragments of mollusc shells contained in basal till indicate marine incursions between some advances, thus documenting extensive deglaciation. A partial chronology based on amino acid studies and radiocarbon dating suggests that five of these advances occurred during the last glacial cycle. The most extensive advances may have culminated during substages of marine isotope stage 5 (substage 5b or 5d) and/or during stage 4. Slightly less extensive advances occurred between ca. 28,000 and 14,000 yr B.P.

Original languageEnglish (US)
Pages (from-to)133-148
Number of pages16
JournalQuaternary Research
Volume44
Issue number2
DOIs
StatePublished - Sep 1995
Externally publishedYes

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last glaciation
Last Glacial
glacial landform
strait
deglaciation
stratigraphy
glacier advance
marine isotope stage
ice cap
radiocarbon dating
mollusc
shear stress
chronology
mass balance
amino acid
shell
ice
lake
Straits
Chile

ASJC Scopus subject areas

  • Earth-Surface Processes
  • Earth and Planetary Sciences(all)

Cite this

The Last Glaciation in Central Magellan Strait, Southernmost Chile. / Clapperton, Chalmers M.; Sugden, David E.; Kaufman, Darrell S; McCulloch, Robert D.

In: Quaternary Research, Vol. 44, No. 2, 09.1995, p. 133-148.

Research output: Contribution to journalArticle

Clapperton, Chalmers M. ; Sugden, David E. ; Kaufman, Darrell S ; McCulloch, Robert D. / The Last Glaciation in Central Magellan Strait, Southernmost Chile. In: Quaternary Research. 1995 ; Vol. 44, No. 2. pp. 133-148.
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