Multiple cosmogenic nuclides document complex Pleistocene exposure history of glacial drifts in Terra Nova Bay (northern Victoria Land, Antarctica)

2009 ◽  
Vol 71 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Luigia Di Nicola ◽  
Stefan Strasky ◽  
Christian Schlüchter ◽  
Maria Cristina Salvatore ◽  
Naki Akçar ◽  
...  
Keyword(s):  
Volcanic Field ◽  
Glacial Cycles ◽  
Erosion Rates ◽  
Terra Nova Bay ◽  
Geological Surveys ◽  
Victoria Land ◽  
History Of ◽  
Terra Nova ◽  
Exposure Ages ◽  
The Last Glacial

AbstractGeomorphological and glacial geological surveys and multiple cosmogenic nuclide analyses (10Be, 26Al, and 21Ne) allowed us to reconstruct the chronology of variations prior to the last glacial maximum of the East Antarctic Ice Sheet (EAIS) and valley glaciers in the Terra Nova Bay region. Glacially scoured coastal piedmonts with round-topped mountains occur below the highest local erosional trimline. They represent relict landscape features eroded by extensive ice overriding the whole coastal area before at least 6 Ma (pre-dating the build-up of the Mt. Melbourne volcanic field). Since then, summit surfaces were continuously exposed and well preserved under polar condition with negligible erosion rates on the order of 17 cm/Ma. Complex older drifts rest on deglaciated areas above the younger late-Pleistocene glacial drift and below the previously overridden summits. The combination of stable and radionuclide isotopes documents complex exposure histories with substantial periods of burial combined with minimal erosion. The areas below rounded summits were repeatedly exposed and buried by ice from local and outlet glaciers. The exposure ages of the older drift(s) indicate multiple Pleistocene glacial cycles, which did not significantly modify the pre-existing landscape.

Limited Pliocene/Pleistocene glaciation in Deep Freeze Range, northern Victoria Land, Antarctica, derived from in situ cosmogenic nuclides

2003 ◽  
Vol 15 (4) ◽  
pp. 493-502 ◽  
Author(s):  
PETER OBERHOLZER ◽  
CARLO BARONI ◽  
JOERG M. SCHAEFER ◽  
GIUSEPPE OROMBELLI ◽  
SUSAN IVY OCHS ◽  
...  
Keyword(s):  
Cosmogenic Nuclides ◽  
Dry Valleys ◽  
Climate Regime ◽  
Erosion Rates ◽  
Terra Nova Bay ◽  
New Information ◽  
Victoria Land ◽  
Exposure Ages ◽  
Middle Pliocene

The question of how stable the climate in Antarctica has been during the last few million years compared to the rest of the planet is still controversial. This study attempts to add new information to the discussion by reconstructing the timing and spatial extent of glacial advances in northern Victoria Land over tens of thousands to millions of years. In Terra Nova Bay region, surface exposure ages and erosion rates of glacially rounded bedrock and glacial erratics have been determined using the cosmogenic nuclides 3He, 10Be and 21Ne. Three morphological units have been analysed. They yield minimum ages of 11 to 34 ka, 309 ka, and 2.6 Ma, respectively. Erosion rates were as low as 20 cm Ma−1 since middle Pliocene time. Taking erosion into account, the oldest surface is 5.3 Ma old. Pleistocene glacier advances had considerable extent, reaching up to 780 m above modern ice levels, but have been restricted to the valleys since at least mid-Pliocene. The existence of landscapes of mid-Pliocene age in northern Victoria Land implies that the climatic stability of the McMurdo Dry Valleys is not unique within the Transantarctic Mountains, but rather the expression of a constantly cold and hyperarid climate regime in entire Victoria Land.

Significance of selected halocarbons monitoring in air samples collected in the Terra Nova Bay region (northern Victoria Land, Antarctica)

1999 ◽  
Vol 11 (2) ◽  
pp. 261-264 ◽  
Author(s):  
Filippo Mangani ◽  
Michela Maione ◽  
Luciano Lattanzi
Keyword(s):  
Ross Sea ◽  
Atmospheric Concentration ◽  
Air Samples ◽  
Terra Nova Bay ◽  
Victoria Land ◽  
Rate Of Increase ◽  
Terra Nova ◽  
Concentration Levels

CCl3F (or CFC-11) and CCl2F2 (or CFC-12) were determined in air samples collected, during subsequent summer Antarctic campaigns, in different sampling sites in the Ross Sea Region. The samples were analysed by GC-ECD after enrichment. Data obtained since 1988–89 were plotted to observe the trend of CFCs atmospheric concentration levels. A decrease in the rate of increase of CFC-12 concentration was observed, whilst the concentration of CFC-11 was actually seen to be decreasing.

scholarly journals Morphology and late Cenozoic (<5 Ma) glacial history of the area between David and Mawson Glaciers, Victoria Land, Antarctica

1994 ◽  
Vol 20 ◽  
pp. 55-60
Author(s):  
Anja L.L.M. Verbers ◽  
Volkmar Damm
Keyword(s):  
Ice Sheet ◽  
Field Work ◽  
Topographic Map ◽  
Glacial History ◽  
Ice Surface ◽  
Victoria Land ◽  
Radio Echo Sounding ◽  
History Of ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Glacio-geological field work and radar ice-thickness sounding were carried out in the area between David and Mawson Glaciers. A subglacial topographic map has been compiled from radio-echo-sounding data. The northern part of this map shows that the trench of David Glacier reaches a depth of more than 1000 m below sea level. The area south of David Glacier comprises a landscape of nunatak clusters dissected by glaciated valleys with ice thicknesses as much as 800 m. Subglacial cirques occur at the outer margins of the nunatak clusters. A model for the regional glacial history is proposed. It starts with a major deglaciation in the Pliocene, which results in marine transgression in basins west of the Transantarctic Mountains. During the late Pliocene, the ice advanced towards the northeast, depositing a thin layer of (Sirius Group) till containing reworked mid-Pliocene marine diatoms. Due to accelerated mountain uplift, the ice cut iIlto the pre-Pliocene peneplain, eroding broad valleys. A period of ice-sheet retreat followed to expose a landscape of large nunataks separated by wide valleys. During this period, local cirque glaciation occurred. When the ice sheet advanced again, another phase of uplift forced the glaciers to cut deeper into the valleys. Probably since the Last Glacial Maximum the ice surface has lowered by about 100 m.

scholarly journals Morphology and late Cenozoic (<5 Ma) glacial history of the area between David and Mawson Glaciers, Victoria Land, Antarctica

1994 ◽  
Vol 20 ◽  
pp. 55-60
Author(s):  
Anja L.L.M. Verbers ◽  
Volkmar Damm
Keyword(s):  
Ice Sheet ◽  
Field Work ◽  
Topographic Map ◽  
Glacial History ◽  
Ice Surface ◽  
Victoria Land ◽  
Radio Echo Sounding ◽  
History Of ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Glacio-geological field work and radar ice-thickness sounding were carried out in the area between David and Mawson Glaciers. A subglacial topographic map has been compiled from radio-echo-sounding data. The northern part of this map shows that the trench of David Glacier reaches a depth of more than 1000 m below sea level. The area south of David Glacier comprises a landscape of nunatak clusters dissected by glaciated valleys with ice thicknesses as much as 800 m. Subglacial cirques occur at the outer margins of the nunatak clusters. A model for the regional glacial history is proposed. It starts with a major deglaciation in the Pliocene, which results in marine transgression in basins west of the Transantarctic Mountains. During the late Pliocene, the ice advanced towards the northeast, depositing a thin layer of (Sirius Group) till containing reworked mid-Pliocene marine diatoms. Due to accelerated mountain uplift, the ice cut iIlto the pre-Pliocene peneplain, eroding broad valleys. A period of ice-sheet retreat followed to expose a landscape of large nunataks separated by wide valleys. During this period, local cirque glaciation occurred. When the ice sheet advanced again, another phase of uplift forced the glaciers to cut deeper into the valleys. Probably since the Last Glacial Maximum the ice surface has lowered by about 100 m.

The history of Granite House and the western geological party of Scott's Terra Nova expedition

Polar Record ◽  
1993 ◽  
Vol 29 (170) ◽  
pp. 219-224 ◽  
Author(s):  
B. Schroeter ◽  
T.G.A. Green ◽  
R.D. Seppelt
Keyword(s):  
Sea Ice ◽  
Rock Shelter ◽  
Meeting Point ◽  
Victoria Land ◽  
History Of ◽  
Terra Nova

ABSTRACTIn summer 1911—1912, during Robert Falcon Scott's Terra Nova expedition (1910–1913) a field party of four men led by the geologist Griffith Taylor surveyed the coast and hinterland of Victoria Land, Antarctica. During their stay at Cape Geology (77°00'S, 162°35'E), Granite Harbour, the members of the ‘western geological party’ built Granite House, a rock shelter used as a kitchen. The field party finished its work in the Granite Harbour region in the second week of January 1912, but heavy sea ice prevented Terra Nova from reaching the prearranged meeting point at the entrance to the bay. Faced with the possibility of being trapped for the winter, the party left Granite Harbour and travelled overland back toward the winter quarters on Ross Island. One month later the party was picked up by Terra Nova and was returned safely to Cape Evans. During an expedition to Granite Harbour in January-February 1992, the authors discovered an 80-year-old note left by the field party in a cigarette tin in the vicinity of Granite House. Dated 14 January 1912, the note was written by Taylor to Lieutenant H.L.L. Pennell, the skipper of Terra Nova, to let him know that the party had left for Cape Roberts. Granite House is a significant relic of the ‘heroic era’ and merits protection.

scholarly journals Postglacial alluvial fan dynamics in the Cordillera Oriental, Peru, and palaeoclimatic implications

2018 ◽  
Vol 91 (1) ◽  
pp. 431-449 ◽  
Author(s):  
Kevin Ratnayaka ◽  
Ralf Hetzel ◽  
Jens Hornung ◽  
Andrea Hampel ◽  
Matthias Hinderer ◽  
...  
Keyword(s):  
Regional Climate ◽  
Transport Processes ◽  
Alluvial Fan ◽  
Alluvial Fans ◽  
Primary Control ◽  
Sediment Delivery ◽  
Data Set ◽  
Erosion Rates ◽  
History Of ◽  
Exposure Ages

AbstractAlluvial fans record climate-driven erosion and sediment-transport processes and allow reconstructing past environmental conditions. Here we investigate the sedimentation history of two alluvial fans located in formerly glaciated valleys of the Cordillera Oriental, Peru.10Be exposure ages from the fan surfaces and radiocarbon ages from the fan interiors constrain the final stages of fan formation. The10Be and14C ages cluster mainly between 13.3–9.3 ka and 11,500–9700 cal yr BP, respectively. Our age data set indicates that—after deglaciation—large amounts of fan sediment were deposited until ∼10 ka, when sedimentation rates declined rather abruptly. This pattern is supported by10Be erosion rates for the fan catchments, because under the assumption of constant erosion the time needed to erode the material stored in the fans significantly exceeds their age. Correlating our ages with regional climate records indicates that precipitation exerts the primary control on fan sedimentation. Two periods with elevated lake levels and increased precipitation between 18 and 14.5 ka and from 13 to 11.5 ka resulted in rapid deposition of large fan lobes. Subsequently, lower precipitation rates decreased erosion in the catchments and sediment delivery to the fans, which have remained largely inactive since ∼9.5 ka.

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