The provenance of Danubian loess

Source areas of the Eastern Ebro Valley loess (NE Iberian Peninsula): Heavy mineral composition as a provenance indicator

“…The Eastern Ebro Valley loess have a very coarse mean (40–52 μm) and mode (50–79 μm) grain size, comparable with that of sandy loess in Belgium (Bertran et al, 2021) and Tunisia (Coudé‐Gaussen, 1990; Faust et al, 2020). These coarse textures suggest very proximal source areas (Pye, 1995), mainly related to fluvial alluvial plains (Fenn et al, 2022; Lehmkuhl et al, 2016; Smalley et al, 2009). The most relevant criteria to establish source areas and loess depositional regions are the geomorphological settings, grain size distribution and specifically tracer mineral composition.…”

“…Very heavy minerals (VHM), heavier than 3.32 g/cm 3 , were also determined as those sinking into the diiodomethane. This gravity method has been used successfully in previous mineral studies (Fenn et al, 2022; Gonçalves et al, 2017; Lin et al, 1992; Morton, 1985; Takehara et al, 2018). VHM include zircon, augite, diopside, staurolite, rutile, barite, garnet group, epidote and kyanite, these being the most representative.…”

“…To establish the loess source areas, various techniques have been developed based on the recognition of specific or tracing characteristics in both sediments and source areas. The techniques consisted of the identification of heavy minerals (Chmielowska & Salata, 2020; Muhs et al, 2018; Peng et al, 2016; Thamó‐Bozsó et al, 2014; Wolf et al, 2019), geochemical composition (Bosq et al, 2020; Schatz et al, 2015; Waroszewski et al, 2021) and U–Pb isotope analysis of zircons (Fenn et al, 2022; Újvári et al, 2016; Wolf et al, 2021). One of the most useful and effective methods is the comparison of sets of heavy minerals present in the loess sand fraction and their potential source materials: fluvial terraces and regional lithological substrates (Chmielowska & Salata, 2020; Peng et al, 2016; Thamó‐Bozsó et al, 2014; Wolf et al, 2021).…”

Loss of loess in the geological record due to poor preservation

“…The formation of extensive loess deposits requires (1) abundant loose, fine‐grained material at the source, (2) competent wind systems to transport large quantities of dust and (3) a trapping mechanism such as vegetation, a wetted surface, or a topographic obstacle to accumulate the dust (Lehmkuhl et al, 2021; Muhs, 2013; Muhs & Bettis, 2003; Pye, 1995; Wright et al, 2001; Zheng, 2016). The Quaternary period has been suggested to be especially suitable for the formation of loess because glacial grinding and possibly frost cracking produced vast amounts of silt, which was easily deflated from dry and unvegetated floodplains and continental shelves during glacials (Assallay et al, 1998; Bateman, 2013; Fenn et al, 2022; Herman et al, 2013; Herman & Champagnac, 2016; Lehmkuhl et al, 2021; Li et al, 2020; Mahowald et al, 1999; Muhs & Bettis, 2003; Schaffernicht et al, 2020; Smalley, 1966; Soreghan et al, 2016; Wright, 2001). However, other mechanisms such as abrasion by wind and water, chemical and salt weathering, aggregation of clay minerals and inheritance from fine‐grained parent rocks can produce large quantities of silt as well (Fenn et al, 2022; Lancaster, 2020; Muhs & Bettis, 2003; Potter et al, 2005; Wright, 2001, 2007).…”

Detailed Luminescence Dating of Dust Mass Accumulation Rates Over the Last Two Glacial-Interglacial Cycles from the Irig Loess-Palaeosol Sequence, Carpathian Basin

“…Presuming that the main dust sources for Irig are major rivers draining central European mountain belts (e.g. Fenn et al, 2022), this suggests that sediment availability from these systems was reduced during MIS 3 and/or that the regional wind dynamics was reduced. In the first scenario, either sediment load in rivers was reduced due to less production or availability of sediment in mountain source regions, or river hydrology or conditions on floodplains were not conducive to making sediments available for deflation.…”