Publication details for Professor Mike BentleyBentley, M.J., Sugden, D.E., Hulton, N.R.J. & McCulloch, R.D. (2005). The Landforms and Pattern of Deglaciation in the Strait of Magellan and Bahía Inútil, Southernmost South America. Geografiska Annaler, Series A: Physical Geography 87(2): 313-333.
- Publication type: Journal Article
- ISSN/ISBN: 0435-3676, 1468-0459
- DOI: 10.1111/j.0435-3676.2005.00261.x
- Keywords: Last Glaciation, Chile, Paleoclimate, Quaternary, Patagonia.
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
We report the results of glacial geomorphological mapping of the Strait of Magellan and Bahía Inútil, southernmost South America. Our aims are to determine the pattern and process of deglaciation during the last glacial–interglacial transition, and to provide a firm geomorphological basis for the interpretation of radiocarbon, cosmogenic isotope and amino acid dates for the timing of deglaciation. The area is important because it lies in a southerly location, providing a link between Antarctica and southern mid-latitudes, and also lies in the zone of the southern westerlies which are a key element in regional climate change.
Our mapping shows that it is possible to make a clear weathering and morphological distinction between last glaciation and older landforms and sediments. Within the last glacial deposits we have identified a number of former glacier limits. The key to delineating many of these limits is continuous meltwater channels that run for several kilometres along the outer edge of discontinuous moraine belts. There are four distinct belts of moraines within the deposits of the last glaciation in the central part of the Strait of Magellan. There are two closely spaced major limits (Band C) at the north end of the Strait that reach Punta Arenas airport on the west side, and Península Juan Mazia on the east side. A third limit (D) terminates south of Punta Arenas on the west side, and passes close to Porvenir on the east. In Bahía Inútil there is a more complex pattern with a prominent outer limit (C) and a series of four equally prominent limits (D1 to D4) on both sides of the bay. South of these limits, there is a fourth group of moraine limits (E) on both coasts of the northern end of Isla Dawson, reflecting the last fluctuations of the Magellan glacier before final deglaciation of the southern end of the Strait.
There are a number of drumlins within the outer moraine limits. The drumlins are draped by small, younger moraines showing that they have been overridden by subsequent advance(s). The coastlines of the study area are cut by a number of shorelines which record the presence of ice-dammed lakes in the Strait of Magellan and Bahía Inútil during the later stages of deglaciation. We conclude that there are four main readvances or stillstands that marked the transition from the Last Glacial Maximum to the onset of the Holocene.
Auer, V., 1956: The Pleistocene of Fuego-Patagonia. Part I: the ice
and interglacial ages. Annales Academia Scientarium Fenicae
AIII, 45: 1–22.
Auer, V., 1959: The Pleistocene of Fuego-Patagonia. Part 3:
shoreline displacements. Annales Academia Scientarium
Fenicae AIII, 60: 1–247.
Benn, D.I. and Clapperton, C., 2000a: Pleistocene glacitectonic
landforms and sediments around central Magellan Strait,
southernmost Chile: evidence for fast outlet glaciers with coldbased
margins. Quaternary Science Reviews, 19: 591–612.
Benn, D.I. and Clapperton, C., 2000b: Glacial sediment-landform
associations and plaeoclimate during the Last Glaciation,
Strait of Magellan, Chile. Quaternary Research, 54: 13–23.
Bentley, M.J. and McCulloch, R.D. 2005: Impact of neotectonics
on the record of glacier and sea level fluctuations, Strait of
Magellan, southern Chile. Geografiska Annaler, 87A: 393–
Brambati, A., De Muro, S. and Di Grande, A., 1995: Distribuzione
dei terrazzi marini e transizionali (Pleistocene ? – Olocene) e
carta geomorfologia della fascia costiera tra Bahia San Felipe
e Paso Ancho, Stretto di Magellano – Cile., 1: 200 000. Programma
Nazionale di recherche in Antartide (PNRA), Trieste.
Brambati, A., De Muro, S. and Di Grande, A., 1998: Marine and
transitional Holocene terraces in the eastern area of the Straits
of Magellan, Chile. Bolletino di Geofisica Teorica ed Applicata,
Caldenius, C., 1932: Las glaciacones cuaternarias en la Patagonia
y Tierra del Fuego. Geografiska Annaler, 14: 1–64.
Clapperton, C.M., Sugden, D.E., Kauffman, D. and McCulloch,
R.D., 1995: The last glaciation in central Magellan Strait,
southermost Chile. Quaternary Research, 44: 133–148.
Darwin, C., 1846: Geological Observations on South America.
Diraison, M., Cobbold, P.R., Gapais, D. and Rossello, E.A., 1997:
Magellan Strait: part of a Neogene rift system. Geology, 25:
Heusser, C.J., 1999: 14C age of glaciation in Estrecho de Magallanes
– Bahía Inútil, Chile. Radiocarbon, 41: 287–293.
Heusser, C.J., Heusser, L.E., Lowell, T.V., Moreira, A. and
Moreira, S., 2000: Deglacial palaeoclimate at Puerto del
Hambre, subantarctic Patagonia, Chile. Journal of Quaternary
Science, 15: 101–114.
McCulloch, R.D. and Bentley, M.J., 1998: Late glacial ice advances
in the strait of Magellan, southern Chile. Quaternary Science
Reviews, 17: 775–787.
McCulloch, R.D. and Davies, S.J., 2001: Late-glacial and
Holocene palaeoenvironmental change in the central Strait of
Magellan, southern Patagonia. Palaeogeography, Palaeoclimatology
and Palaeoecology, 173: 143–173.
McCulloch, R.D., Bentley, M.J., Purves, R.S., Hulton, N.R.J., Sugden,
D.E. and Clapperton, C.M., 2000: Climatic inferences
from glacial and palaeoecological evidence at the last glacial
termination, southern South America. Journal of Quaternary
Science, 15: 409–417.
McCulloch, R.D., Fogwill, C.J., Sugden, D.E., Bentley, M.J. and
Kubik, P.W., 2005a: Chronology of the last glaciation in central
Strait of Magellan and Bahía Inútil, southernmost South
America. Geografiska Annaler , 87 A (2): 289–312.
McCulloch, R.D., Bentley, M.J., Tipping, R.M. and Clapperton,
C.M. 2005b: Evidence for late-glacial ice-dammed lakes in
the central Strait of Magellan and Bahía Inútil, southernmost
South America. Geografiska Annaler, 87 A (2): 335–362.
Meglioli, A., 1992: Glacial geology of southernmost Patagonia,
the Strait of Magellan and northern Tierra del Fuego. PhD
Thesis, Lehight University, USA.
Mercer, J.H., 1969: Glaciation in southern Argentina more than
two million years ago. Science, 164: 823–825.
Mörner, N.-A. and Silwan, C., 1989: Magnetostratigraphy of the
Patagonian moraine sequence at Lago Buenos Aires. Journal
of South American Earth Sciences, 2: 385–390.
Nordenskjöld, O., 1899: Geologie, Geographie und Anthropologie.
Scwedischen Expedition nach den Magellansländern,
1895–1897. Norstedt & Söner. Stockholm.
Porter, S.C., 1990: Character and ages of Pleistocene drifts in a
transect across the Strait of Magellan. Quaternary of South
America and Antarctic Peninsula, 7: 35–49.
Porter, S.C., Stuiver, M. and Heusser, C.J., 1984: Holocene sea
level changes along the Strait of Magellan and Beagle Channel,
southernmost South America. Quaternary Research, 22:
Porter, S.C., Clapperton, C.M. and Sugden, D.E., 1992: Chronology
and dynamics of deglaciation along and near the Strait of
Magellan, southernmost South America. Sveriges Geologiska
Undersökning, Ser. Ca, 81: 233–239.
Prieto, X.V. and Winslow, M.A., 1994: El Cuaternario del Estrecho
de Magallanes I: Sector Punta Arenas-Primera Angostura.
Annales Instituto Patagonia, 21: 85–95.
Rabassa, J. and Clapperton, C.M., 1990: Quaternary Glaciations of
the Southern Andes. Quaternary Science Reviews, 9: 153–174.
Rabassa, J., Bujalesky, G.G., Meglioli, A., Coronato, A., Gordillo,
S., Roig, C. and Salemme, M., 1992: The Quaternary of
Tierra del Fuego, Argentina: the status of our knowledge.
Sveriges Geologiska Undersokning, Ser. CA 81: 249–256.
Rabassa, J., Coronato, A., Bujalesky, G., Salemme, M., Roig, C.,
Meglioli, A., Heusser, C., Gordillo, S., Roig, F., Borromei, A.
and Quattrocchio, M., 2000: Quaternary of Tierra del Fuego,
Southernmost South America: an updated review. Quaternary
International, 68: 217–240.
Radeke, L.D., 1978: Formas del terreno y depositos cuaternarios
Tierra del Fuego central, Chile. Revista Geologica De Chile,
Shreve, R.L., 1972: Movement of water in glaciers. Journal of
Glaciology, 11: 205–214.
Singer, B.S., Ackert, R.P.J. and Guillou, H., 2004: 40Ar/39Ar and
K-Ar chronology of Pleistocene glaciations in Patagonia.
Geological Society of America Bulletin, 116: 434–450.