Fig 16 - uploaded by Daniel R. Muhs
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Distribution and thickness of loess, mostly Peoria Loess of last-glacial age, in central North America. Loess thickness and distribution taken from compilation in Bettis et al. (2003) and sources therein. Last-glacial paleowinds (arrows) are from Muhs and Bettis (2000). Loess localities shown in other figures: M, Moran Canyon; B, Bignell Hill; G; Greenbay Hollow; C, Crowleys Ridge; V; Vicksburg.  

Distribution and thickness of loess, mostly Peoria Loess of last-glacial age, in central North America. Loess thickness and distribution taken from compilation in Bettis et al. (2003) and sources therein. Last-glacial paleowinds (arrows) are from Muhs and Bettis (2000). Loess localities shown in other figures: M, Moran Canyon; B, Bignell Hill; G; Greenbay Hollow; C, Crowleys Ridge; V; Vicksburg.  

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Conference Paper
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Dust flux in the Earth-atmosphere system has varied over both space and time. Dramatic shifts in rates of dust entrainment and deposition have occurred on glacial-period-to-interglacial-period timescales. For example, over much of the Earth's surface, dust deposition rates were much greater during the last glacial period than during the present int...

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Context 1
... extending into the greater Mississippi River drainage basin, from Colorado to Ohio. As in Europe, loess bodies of the North American mid-conti- nent appear to be continuous when viewed broadly. On a finer scale, however, it is apparent that individual loess bodies have very different thickness trends that are not part of a larger regional trend (Fig. ...
Context 2
... of the Missouri River in the Great Plains region of Nebras- ka, Kansas, and Colorado (Fig. 16), loess is not glaciogenic, but, as discussed above, is derived from volcaniclastic siltstone of Tertiary age. Thus, with a non-glacial source of loess in this region, one should not necessarily expect that loess deposition is a ''turn-on/ turn-off'' phenomenon that is tightly linked to glacial periods. Both radiocarbon and OSL ages of ...
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... by what has been called the ''red clays.'' Sun et al. (1998) Fullerton et al., 2003Fullerton et al., , 2004). and Badlands National Park, South Dakota, where the source of loess, the volcaniclastic siltstone White River Group, is well exposed. Redrawn from data in Muhs et al. (2008a). Fig. 19. Loess stratigraphy at Greenbay Hollow, Illinois (see Fig. 16 for location), which is typical for midcontinental North American loess sequences along the Mississippi River, showing changes in chemical properties in loess units and paleosols (data from Muhs et al., 2001). Also shown is proposed correlation of loess units with the SPECMAP deep-sea oxygen isotope record of Martinson et al. (1987). inferring that ...
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... by glacial grinding and frost shattering, followed by fluvial transport as outwash into the desert basins (Smalley, 1995), and finally entrainment from the ba- sins by wind. Sun (2002a) reports that the loess on the mountains surrounding the desert basins, such as the Taklimakan Desert in Fig. 20. Loess stratigraphy at Moran Canyon, Nebraska (see Fig. 16 the Tarim Basin may have been deflated from the desert floor, but the silt-sized particles are derived originally from the very moun- tains on which they were re-deposited. Thus, his interpretation is that the arid basins of central China may simply act as reservoirs for fine particle storage and have little to do with silt production ...
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... size decrease downwind from a source. Using these trends, a source can be identified and one can infer paleowind directions, a powerful tool for reconstructing atmospheric circulation patterns of the past. Thus, loess thickness and particle size trends indicate last-glacial paleowinds from the west or northwest in mid-continental North America (Figs. 16 and 18) and particle size trends indicate northerly or northwesterly last-glacial paleowinds in China (Fig. 17). In re- gions where a loess source, such as a major river valley carrying gla- cial outwash, is not apparent, isotopic methods can be very useful in Clay-to-silt grain size ratio (<2µm to >10µm) 0 1 2 3 Fig. 22. Loess stratigraphy ...

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