Ubiquitous Holocene dune systems are associated with major west-to-east flowing rivers across the Southern Great Plains (SGP), USA. Critical questions remain as to whether aeolian activity reflects multiple environmental signatures, including increased sand supply from riverine sources. This research focused on the western Red River where geomorphic mapping revealed three terrace levels up to 16 m, buried partially by up to 10 m of aeolian sediments. Pedosedimentary facies analyses of sections and Geoprobe cores extracted from terraces and close-interval optically stimulated luminescence dating of quartz grains revealed two periods of fluvial aggradation at ca. 80 ka to ~5 to 8 m above the Red River forming the Vernon terrace, and at 30 to 13 ka to ~20–15 m, the highest identified Childress terrace. Net degradation of 20 m also occurred between 13 and 7 ka to 4 m below the current channel, reflecting regional fall in the groundwater level. The latest aggradation event, which built the lowest Luna terrace at ~2 m, ended 1.5 to 0.7 ka and was partially buried by fluvial-sourced dunes in the sixteenth and seventeenth centuries. This recent phase of aeolian deposition coincides with a comparatively wet period in the central United States during the Little Ice Age, rather than with regional drying.

The Roca San Miguel (RSM) archaeological site was occupied during Mousterian times. Here we present a geoarchaeological and paleoenvironmental reconstruction of the site. Five stratigraphic units (A to E) formed by different archaeological levels are identified. Three optically stimulated luminescence (OSL) ages show that Unit A dates to between 169.6 ± 9.1 and 151.9 ± 11.1 ka, during the penultimate glacial period (PGP), and contains numerous signs of recurring hearths. Unit B is unexcavated. Unit C dates to between 118.9 ± 11.5 and 103.4 ± 6.9 ka (late Eemian–marine isotope stage (MIS) 5d) and shows an abundance of lithic remains as well as some faunal elements. Unit C is covered by Unit D, which incorporates materials moved downslope, and is dated at 81.2 ± 4.7 ka. These OSL ages concur with U/Th ages (129.3 ± 1.5 and 123.6 ± 0.6 ka) derived from a flowstone covered by both -C and D- post-flowstone units. Finally, Unit E covers the archaeological site, which was partially eroded during MIS2. The robust and well-constrained chronology of the RSM site and surroundings enables the establishment of its evolutionary model from the PGP to the last glacial cycle. The RSM site is the oldest Neanderthal occupation accurately dated in the Pre-Pyrenean region.

The stratigraphy and sedimentology of the Q3 middle terrace alluvial sequence in the lower Tagus river valley, Portugal, were studied near the village of Alpiarça, approximately 40 km upstream from the estuarine area. Two main stratigraphic units were recognized, separated by an important uncomformity. The Lower Gravels unit (LG) consists of intercalations of medium to coarse gravel deposits, mainly quartzitic, with coarse sandy matrix, organized in tabular bodies. The overlying Upper Sands unit (US) consists of tabular sandy channel deposits and overbank fines, the latter containing well-developed paleosols and backswamp deposits, showing a general aggrading trend, apparently with varying rates; available data indicate that deposition of the US took place under temperate climatic conditions. Within US deposits are several paleolithic archaeological sites, the lower ones in the alluvial stratigraphy being Middle Acheulian, whereas those embedded in overlying deposits are, from bottom to top, Upper Acheulian and Micoquian. Some of these sites have been recently excavated. The quartzite artifacts were apparently abandoned by early humans on the flood plain surface during deposition of the US unit and were subjected to limited reworking during their incorporation in the alluvium. TL/OSL dating of sandy-silty sediments, though imprecise, support archaeological evidence pointing to an age of 150,000 to 70,000 yr B.P. for the US unit.

Exposure age dating using in situ10Be and 26Al is a very useful technique for dating fluvial terraces. This is especially true in semiarid regions where other methods suffer from a paucity of suitable dating materials. This article describes sample preparation procedures and analytical benchmarks established at the Xi’an Accelerator Mass Spectrometry (AMS) Center for the study of in situ10Be and 26Al. Four intercomparison samples were analyzed in the study, using an improved sample preparation method. The exposure age results are shown to be in good agreement with published data, and demonstrate the reliability of the dating method. This article also presents new 10Be and 26Al results from quartz samples collected from a series of fluvial terraces from Guanshan River, along the Qilian Shan, northeastern Tibetan Plateau. The ages of three fluvial terraces from the Jinfosi site are shown to be (56.4±5.3) ka for T3, (10.7±1.0) ka for T2, and (7.2±1.0) ka for T1. The dating results are consistent with published data from the same region (10Be, 14C, and optically stimulated luminescence dating methods). A comparison of high-resolution climate records with age constraints for the terrace formation shows a close relationship between terrace formation and climate change.

This paper aims to provide a synthesis and update concerning the fluvial terraces of the rivers flowing from the Vosges Massif (Moselle and palaeo Upper-Moselle-Meuse, Meurthe, Sarre). The terraces of these rivers are especially well-developed in the marly depressions of the Eastern Paris Basin, justifying an extensive field mapping expedition. The main rivers exhibit terrace staircases with 8 to 13 stepped terrace steps within 100m of the present valley floor. The fluvial sediments mainly originate from the Vosges Massif (crystalline basement and Permo-Triassic sandstones and conglomerates). Another peculiarity of the study area is the presence of several palaeovalleys, typically related to fluvial capture events which occurred to the detriment of the River Meuse. Many palaeomeanders have also been recognised in the Paris Basin (Meuse catchment), and the Rhenish Massif (Moselle and Sarre valleys). Despite some similarities, palaeoenvironmental reconstructions provide evidence for the terrace staircases being distinct from one valley / section of valley to another. These differences are related to the morphostructural framework and to the climate forcing (presence/absence of glaciers in the upper catchment of the rivers). The chronological framework suggests that the terrace sequences and the main capture events may be older than previously thought.