Surficial geology and geomorphology of eastern and central Wright Valley, Antarctica

Hall, Brenda L.; Denton, George H.

doi:10.1016/j.geomorph.2004.05.002

Cited by 58 publications

(66 citation statements)

References 35 publications

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“…Hall and Denton [2005] suggest that sea ice may have reached an elevation of 750 m in Eastern Wright Valley in the late Pliocene The results of this study show that Hart ash site has not been buried by ice or water in the past ∼1 Ma. Although we can create a well-fitting exposure model that includes burial at this site for 2.2 Ma followed by erosion for 1.3 Ma, the dominant signature in the nuclide concentrations is erosion for the past ∼1 Ma.…”

Section: Implications For Glacial Historymentioning

confidence: 65%

Quantifying regolith erosion rates with cosmogenic nuclides ¹⁰Be and ²⁶Al in the McMurdo Dry Valleys, Antarctica

Morgan¹,

Putkonen²,

Balco³

et al. 2010

J. Geophys. Res.

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[1] The McMurdo Dry Valleys, Antarctica (MDV) are among the oldest landscapes on Earth, and some landforms there present an intriguing apparent contradiction such that millions of years old surface deposits maintain their meter-scale morphology despite the fact that measured erosion rates are 0.1-4 m Ma −1 . We analyzed the concentration of cosmic ray-produced 10 Be and 26 Al in quartz sands from regolith directly above and below two well-documented ash deposits in the MDV, the Arena Valley ash ( 40 Ar/ 39 Ar age of 4.33 Ma) and the Hart ash (K-Ar age of 3.9 Ma). Measured concentrations of 10 Be and 26 Al are significantly less than expected given the age of the in situ air fall ashes and are best interpreted as reflecting the degradation rate of the overlying sediments. The erosion rate of the material above the Arena Valley ash that best explains the observed isotope profiles is 3.5 ± 0.41 × 10 −5 g cm) for the past ∼4 Ma. For the Hart ash, the erosion rate is 4.8 ± 0.21 × 10 −4 g cm −2 yr −1 (∼2.6 m Ma) for the past ∼1 Ma. The concentration profiles do not show signs of mixing, creep, or deflation caused by sublimation of ground ice. These results indicate that the slow, steady lowering of the surface without vertical mixing may allow landforms to maintain their meter-scale morphology even though they are actively eroding.

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Section: Implications For Glacial Historymentioning

confidence: 65%

Quantifying regolith erosion rates with cosmogenic nuclides ¹⁰Be and ²⁶Al in the McMurdo Dry Valleys, Antarctica

Morgan¹,

Putkonen²,

Balco³

et al. 2010

J. Geophys. Res.

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“…The Peleus till, the oldest drift recognized in the valley, was deposited before 3.9 Ma by a wet-based glacier draining the East Antarctic Ice Sheet that filled Wright Valley (Prentice et al, 1993). The second system represents grounded ice from the Ross Sea Embayment (Wright glaciations), which advanced westward into Wright Valley on at least seven occasions to at least 21 km beyond the margin of presentday Wright Lower Glacier (Hall and Denton, 2005). These advances are believed to be contemporaneous with Northern Hemisphere glaciations.…”

Section: Experimental Sitementioning

confidence: 99%

“…The Trilogy drift was considered by Hall and Denton (2005) to be early to mid-Quaternary in age. However, soils on Trilogy drift are less strongly developed that those on hummocky drifts of mid-to late Quaternary age (Table 1, Fig.…”

Section: Soil Evolution In Wright Valleymentioning

confidence: 99%

“…Therefore, cryoturbation of Trilogy soils on the valley floor may preclude the full expression of the soil. Similarly, the Loke drift, which occurs in the comparatively moist eastern part of the valley and is considered by Hall and Denton (2005) to be midto late Quaternary in age, lacks soil development commensurate with its assigned age.…”

Section: Soil Evolution In Wright Valleymentioning

confidence: 99%

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Soil formation in Wright Valley, Antarctica since the late Neogene

Bockheim

McLeod

2006

Geoderma

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“…These soils no longer have ice-cemented per- mafrost in the upper 1 m to sustain these processes; rather, they contain dry-frozen permafrost from depths of 0.2 to 1 m or more from a progressive loss in soil moisture following the onset of hyper-arid conditions. The surficial geology map of central Wright Valley (Hall and Denton, 2005) was used to delineate areas of relict, buried, and modern soils. Approximately 55 % of the soils are relict and approximately 10 % of the area contains buried soils (map not shown).…”

Section: Evidence For Relict Soilsmentioning

confidence: 99%

Paleosols in the Transantarctic Mountains: indicators of environmental change

Bockheim

2013

Solid Earth

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Abstract. The Transantarctic Mountains (TAMs), a 3500 km long chain that subdivides East Antarctica from West Antarctica, are important for reconstructing the tectonic, glacial, and climatic history of Antarctica. With an ice-free area of 24 200 km 2 (50 % of the total in Antarctica), the TAMs contain an unusually high proportion of paleosols, including relict and buried soils. The unconsolidated paleosols range from late Quaternary to Miocene in age, the semiconsolidated paleosols are of early Miocene to Oligocene age, and the consolidated paleosols are of Paleozoic age. Paleosols on unconsolidated deposits are emphasized in this study. Examples are given from the McMurdo Dry Valleys (78 • S) and two outlet glaciers in the central and southern TAMS, including the Hatherton-Darwin Glacier region (80 • S) and the Beardmore Glacier region (85 • 30 S). Relict soils constitute 73 % of all of the soils examined; 10 % of the soils featured burials. About 26 % of the soils examined are from the last glaciation (< 117 ka) and have not undergone any apparent change in climate. As an example, paleosols comprise 65 % of a mapped portion of central Wright Valley. Paleosols in the TAMs feature recycled ventifacts and buried glacial ice in excess of 8 Ma in age, and volcanic ash of Pliocene to Miocene age has buried some soils. Relict soils are more strongly developed than nearby modern soils and often are dry-frozen and feature sand-wedge casts when ice-cemented permafrost is present. The preservation of paleosols in the TAMs can be attributed to cold-based glaciers that are able to override landscapes while causing minimal disturbance.

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Surficial geology and geomorphology of eastern and central Wright Valley, Antarctica

Cited by 58 publications

References 35 publications

Quantifying regolith erosion rates with cosmogenic nuclides ¹⁰Be and ²⁶Al in the McMurdo Dry Valleys, Antarctica

Quantifying regolith erosion rates with cosmogenic nuclides ¹⁰Be and ²⁶Al in the McMurdo Dry Valleys, Antarctica

Soil formation in Wright Valley, Antarctica since the late Neogene

Paleosols in the Transantarctic Mountains: indicators of environmental change

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Surficial geology and geomorphology of eastern and central Wright Valley, Antarctica

Cited by 58 publications

References 35 publications

Quantifying regolith erosion rates with cosmogenic nuclides 10Be and 26Al in the McMurdo Dry Valleys, Antarctica

Quantifying regolith erosion rates with cosmogenic nuclides 10Be and 26Al in the McMurdo Dry Valleys, Antarctica

Soil formation in Wright Valley, Antarctica since the late Neogene

Paleosols in the Transantarctic Mountains: indicators of environmental change

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Product

Resources

About

Quantifying regolith erosion rates with cosmogenic nuclides ¹⁰Be and ²⁶Al in the McMurdo Dry Valleys, Antarctica

Quantifying regolith erosion rates with cosmogenic nuclides ¹⁰Be and ²⁶Al in the McMurdo Dry Valleys, Antarctica