scholarly journals Terrestrial cosmogenic surface exposure dating of glacial and associated landforms in the Ruby Mountains-East Humboldt Range of central Nevada and along the northeastern flank of the Sierra Nevada

Geomorphology ◽  
2016 ◽  
Vol 268 ◽  
pp. 72-81 ◽  
Author(s):  
Steven G. Wesnousky ◽  
Richard W. Briggs ◽  
Marc W. Caffee ◽  
F.J. Ryerson ◽  
Robert C. Finkel ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Ruby Mountains ◽  
Northeastern Flank ◽  
East Humboldt Range

Chronology of glaciations in the Sierra Nevada, California, from 10Be surface exposure dating

2011 ◽  
Vol 30 (5-6) ◽  
pp. 646-661 ◽  
Author(s):  
Dylan H. Rood ◽  
Douglas W. Burbank ◽  
Robert C. Finkel
Keyword(s):  
Sierra Nevada ◽  
Surface Exposure Dating ◽  
Exposure Dating

Accurate surface exposure dating with lichens

2018 ◽  
Vol 90 (1) ◽  
pp. 1-9 ◽  
Author(s):  
William B. Bull
Keyword(s):  
Sierra Nevada ◽  
Surface Rupture ◽  
Ground Shaking ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Crustose Lichen ◽  
The North ◽  
San Andreas ◽  
Spatial Attenuation ◽  
Lichen Growth

AbstractLichenometry accurately dates exposure times of glacial moraines and landslides when measuring the longest axis of the largest crustose lichen on many blocks, as demonstrated by numerous examples. In Sweden, the sizes ofRhizocarponsubgenusRhizocarpondescribe five pulses of glacial moraine creation in 120 yr. Six historic California earthquakes, between AD 1800 and 1906, caused many landslides that constrain lichen growth as linear with a dating accuracy of±0.5 yr. Crustose lichen sizes date earthquake-created additions to Sierra Nevada talus with an accuracy of±5 yr. The oldest lichen ages are 400 yr forLecanora sierrae, 800 yr forLecidea atrobrunnea, and 1100 yr forAcarospora chlorophanaandRhizocarponsubgenusRhizocarpon. Lichen sizes also record differing spatial attenuation of ground shaking from the magnitude (Mw) ~7.9 San Andreas earthquake of AD 1857 and the more distant, smaller San Jacinto AD 1800 earthquake, which both caused Sierra Nevada rockfalls. AD 1800 seismic shaking was relatively stronger than that of AD 1857 farther north, perhaps expressing stronger Love and Rayleigh styles of surface waves from the north-trending AD 1800 surface rupture that were particularly efficient in causing rockfalls at greater distances.

scholarly journals Glacial Chronology of the Ruby Mountains-East Humboldt Range, Nevada

1984 ◽  
Vol 21 (3) ◽  
pp. 286-303 ◽  
Author(s):  
William J. Wayne
Keyword(s):  
Great Lakes ◽  
Sierra Nevada ◽  
Basin And Range Province ◽  
Wasatch Mountains ◽  
Relative Dating ◽  
Ruby Mountains ◽  
Order Of Magnitude ◽  
Morphological Differences ◽  
Lake Deposits ◽  
East Humboldt Range

The Ruby Mountains-East Humboldt Range, one of the interior mountain groups of the Basin and Range Province, lies about midway between the Wasatch Mountains and the Sierra Nevada. After Blackwelder's description in his review of glaciation in the western mountains, Sharp mapped and named the deposits of the Lamoille and Angel Lake glaciations and correlated them with early and late Wisconsin deposits of the Great Lakes area. The refinement of relative dating (RD) methods, the availability of airphotos and modern topographic maps, and new road cuts have aided the restudy of these alpine glacial deposits and the basis for their correlation. Lamoille moraines are smooth ridges and show little detail of constructional topography. Valleys glaciated only by Lamoille ice still show the characteristics of a glaciated trough, but they have been greatly modified by weathering and erosion. Granite boulders on Lamoille moraines are pitted, and pegmatites have grotesque shapes with 30-cm-deep pits. Cuts through Lamoille end moraines (and alluvial talus cones) expose a thick soil profile with a well-developed blocky structure in a reddish-brown argillic B horizon. Subsurface granitic boulders in the B horizon of Lamoille tills show much greater weathering than do those in Angel Lake tills. In contrast, Angel Lake moraines are irregular and rugged, contain closed depressions, and have been little altered since deposition. Surfaces scoured by Angel Lake ice are fresh and unweathered. Granites of Angel Lake moraines have weathered surfaces but show little pitting; pegmatites have pits up to 10 cm deep. The thin soil profiles on Angel Lake tills and alluvial talus cones display brown colors, minor clay accumulation, and no B-horizon structure. These weathering and morphological differences suggest that the Lamoille deposits have been exposed to weathering and erosion for a period of time as much as an order of magnitude longer than the Angel Lake deposits. Thus only the Angel Lake is Wisconsinan in age, and the Lamoille drift is more reasonably correlated with the Illinoian Stage of the Great Lakes region.

Reconstructing the Timing of Flash Floods Using 10Be Surface Exposure Dating at Leidy Creek Alluvial Fan and Valley, White Mountains, California–Nevada, USA

2015 ◽  
Vol 83 (1) ◽  
pp. 178-186 ◽  
Author(s):  
Markus Fuchs ◽  
Rebecca Reverman ◽  
Lewis A. Owen ◽  
Kurt L. Frankel
Keyword(s):  
Flash Floods ◽  
Alluvial Fan ◽  
Optically Stimulated Luminescence ◽  
Alluvial Fans ◽  
White Mountains ◽  
The Holocene ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods

AbstractLarge alluvial fans characterize the piedmonts of the White Mountains, California–Nevada, USA, with large boulders strewn across their surfaces. The boulders are interpreted as flash floods deposits with an unclear trigger for the transport process. Several triggers are possible, including glacial lake outburst floods (GLOFs), thunderstorms or rainfall on snow cover. From a paleoenvironmental perspective, the origin of the flash floods is of fundamental importance. The alluvial fans that flank the White Mountains at Leidy Creek display particularly impressive examples of these deposits. The boulder deposits and the source catchment at Leidy Creek were examined using 10Be terrestrial cosmogenic nuclide (TCN) surface exposure dating to help elucidate their age and origin. All boulders dated on the alluvial fans date to the Holocene. This is in accordance with the geomorphic analyses of the Leidy Creek catchment and its terraces and sediment ridges, which were also dated to the Holocene using optically stimulated luminescence (OSL) and 10Be surface exposure. The results suggest that the boulders on the alluvial fan were deposited by flash floods during thunderstorm events affecting the catchment of the Leidy Creek valley. Paleomonsoonal-induced mid-Holocene flash floods are the most plausible explanation for the discharges needed for these boulder aggradations, but a regional dataset is needed to confirm this explanation.

scholarly journals A zero-exposure time test on an erratic boulder: evaluating the problem of pre-exposure in Surface Exposure Dating

2009 ◽  
Vol 58 (1) ◽  
pp. 1-11
Author(s):  
Lucia A. Abbühl ◽  
Naki Akcar ◽  
Stefan Strasky ◽  
Angela A. Graf ◽  
Susan Ivy-Ochs ◽  
...  
Keyword(s):  
Exposure Time ◽  
Prior Exposure ◽  
Lateral Moraine ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Three Samples ◽  
Time Test ◽  
The Right ◽  
Geometric Relationship ◽  
Erratic Boulder

Abstract. The method of surface exposure dating using in-situ produced cosmogenic nuclides has become an important and widely applied tool in Quaternary science. One application is the dating of erratic boulders on moraines. An important problem however remains: the evaluation of potential pre-exposure time for samples from boulder surfaces. We have tested pre-exposure by sampling all sides of a recently exposed boulder in order to measure inherited nuclides from prior exposure periods. The sampled erratic boulder rests on the right lateral moraine of the most recent advance of the Glacier de Tsijiore Nouve in the Arolla Valley, Switzerland. Mapping of the area was done to reconstruct the Holocene fluctuations of the glacier. This glacier is especially useful for such a test as it is characterized by an ideal geometric relationship between accumulation and ablation area and, therefore, responds rapidly to mass-balance changes. The sampled boulder was deposited in 1991. Assuming no prior exposure the expected concentration of a given cosmogenic nuclide should be near zero. The 10Be/9Be ratios of the five measured samples were indistinguishable from blank values within the given errors, demonstrating that the samples did not experience pre-exposure. Three samples measured for 21Ne reveal 21Ne/20Ne and 22Ne/20Ne ratios similar to those of air, with no detectable prior cosmogenic Ne accumulation.

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