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In September 2016, the annual meeting of the International Union for Quaternary Research’s Loess and Pedostratigraphy Focus Group, traditionally referred to as a LoessFest, met in Eau Claire, Wisconsin, USA. The 2016 LoessFest focused on “thin” loess deposits and loess transportation surfaces. This LoessFest included 75 registered participants from 10 countries. Almost half of the participants were from outside the United States, and 18 of the participants were students. This review is the introduction to the special issue for Quaternary Research that originated from presentations and discussions at the 2016 LoessFest. This introduction highlights current understanding and ongoing work on loess in various regions of the world and provides brief summaries of some of the current approaches/strategies used to study loess deposits. [ABSTRACT FROM AUTHOR]

Loess is widespread over Alaska, and its accumulation has traditionally been associated with glacial periods. Surprisingly, loess deposits securely dated to the last glacial period are rare in Alaska, and paleowind reconstructions for this time period are limited to inferences from dune orientations. We report a rare occurrence of loess deposits dating to the last glacial period, ~19 ka to ~12 ka, in the Yukon-Tanana Upland. Loess in this area is very coarse grained (abundant coarse silt), with decreases in particle size moving south of the Yukon River, implying that the drainage basin of this river was the main source. Geochemical data show, however, that the Tanana River valley to the south is also a likely distal source. The occurrence of last-glacial loess with sources to both the south and north is explained by both regional, synoptic-scale winds from the northeast and opposing katabatic winds that could have developed from expanded glaciers in both the Brooks Range to the north and the Alaska Range to the south. Based on a comparison with recent climate modeling for the last glacial period, seasonality of dust transport may also have played a role in bringing about contributions from both northern and southern sources. [ABSTRACT FROM AUTHOR]

ABSTRACT Analyses of fossil records of molluscs, stable isotopes of carbon and oxygen, diatoms and palynomorphs from alluvial deposits at Arroyo Claromecó, in the southern Pampa region of Argentina, provide an integrated reconstruction of rapid Holocene environmental change related to marine and palaeoclimate influences. The major events recorded include: (i) disturbances produced by marine influences in close proximity to the coast before ca. 7700 cal a BP; (ii) a short-term decrease in salinity associated with freshwater influx between ca. 7700 and 7400 cal a BP in response to eustatic adjustment as sea level rose; (iii) an increasing input of marine water related to the Holocene sea-level highstand and greater evaporative conditions between 7400 and 6450 cal a BP; and (iv) evaporative processes linked to a pronounced climatic variability that triggered changes in water chemistry during the last ca. 6000 cal a BP concurrently with the late Holocene sea-level fall. A comparison of coastal and continental stable isotope records from the Pampa region reveals that evaporation and a negative precipitation/evaporation (P/E) ratio balance strongly influenced water chemistry in the coastal region, and was as important an influence as marine water during the period of maximum sea-level highstand. [ABSTRACT FROM AUTHOR]

Abstract: Geologic archives show that the Earth was dustier during the last glacial period. One model suggests that increased gustiness (stronger, more frequent winds) enhanced dustiness. We tested this at Loveland, Iowa, one of the thickest deposits of last-glacial-age (Peoria) loess in the world. Based on K/Rb and Ba/Rb, loess was derived not only from glaciogenic sources of the Missouri River, but also distal loess from non-glacial sources in Nebraska. Optically stimulated luminescence (OSL) ages provide the first detailed chronology of Peoria Loess at Loveland. Deposition began after ~27ka and continued until ~17ka. OSL ages also indicate that mass accumulation rates (MARs) of loess were not constant. MARs were highest and grain size was coarsest during the time of middle Peoria Loess accretion, ~23ka, when ~10m of loess accumulated in no more than ~2000yr and possibly much less. The timing of coarsest grain size and highest MAR, indicating strongest winds, coincides with a summer-insolation minimum at high latitudes in North America and the maximum southward extent of the Laurentide ice sheet. These observations suggest that increased dustiness during the last glacial period was driven largely by enhanced gustiness, forced by a steepened meridional temperature gradient. [Copyright &y& Elsevier]