Fluvial geomorphology and stratigraphy often reflect past environmental and climate conditions. This study examines the response of Bull Creek, a small ephemeral creek in the Oklahoma panhandle, to environmental conditions through the late Pleistocene and Holocene. Fluvial terraces were mapped and their stratigraphy and sedimentology documented throughout the course of the main valley. Based on their elevations, terraces were broadly grouped into a late-Pleistocene fill terrace (T3) and two Holocene fill-cut terrace sets (T2 and T1). Terrace systems are marked by similar stratigraphies recording the general environmental conditions of the time. Sedimentary sequences preserved in terrace fills record the transition from a perennial fluvial system during the late glacial period and the Younger Dryas to a semiarid environment dominated by loess accumulation and punctuated by flood events during the middle to late Holocene. The highest rates of aeolian accumulation within the valley occurred during the early to middle Holocene. Our data provide significant new information regarding the late-Pleistocene and Holocene environmental history for this region, located between the well-studied Southern and Central High Plains of North America.

The newly identified Paleolithic site Sima de Las Palomas de Teba hosts an almost seven-m-thick sediment profile investigated here to elucidate the rock shelter's chronostratigraphy and formation processes. At its base, the sediment sequence contains rich archeological deposits recording intensive occupation by Neanderthals. Luminescence provides a terminus ante quem of 39.4 ± 2.6 ka or 44.9 ± 4.1 ka (OSL) and 51.4 ± 8.4 ka (TL). This occupation ended with a rockfall event followed by accumulation of archeologically sterile sediments. These were covered by sediments containing few Middle Paleolithic artifacts, which either indicate ephemeral occupation by Neanderthals or reworking as suggested by micromorphological features. Above this unit, scattered lithic artifacts of undiagnostic character may represent undefined Paleolithic occupations. Sediment burial ages between about 23.0 ± 1.5 ka (OSL) and 40.5 ± 3.4 ka (pIRIR) provide an Upper Paleolithic chronology for sediments deposited above the rockfall. Finally, a dung-bearing Holocene layer in the uppermost part of the sequence contains a fragment of a human mandible dated to 4032 ± 39 14C yr BP. Overall, the sequence represents an important new site for studying the end of Neanderthal occupation in southern Spain.

Paleosols record paleoclimatic processes in the Earth's Critical Zone and are archives of ancient landscapes associated with archeological sites. Detailed field, micromorphologic, and bulk geochemical analysis of paleosols were conducted near four sites at Olduvai Gorge, Tanzania within the same stratigraphic horizon as the Zinjanthropus (Paranthropus) boisei archeological site. Paleosols are thin (< 35 cm), smectitic, and exhibit Vertisol shrink–swell features. Traced across the paleolandscape over 1 km and just beneath Tuff IC (1.845 Ma), the paleosols record a paleocatena in which soil moisture at the four sites was supplemented by seepage additions from adjacent springs, and soil development was enhanced by this additional moisture. Field evidence revealed an abrupt lateral transition in paleosol composition at the PTK site (< 1.5 m apart) in which paleosol B, formed nearest the spring system, is highly siliceous, vs. paleosol A, formed in smectitic clay. Thin-section investigations combined with mass-balance geochemistry, using Chapati Tuff as parent material and assuming immobile Ti, show moderately intense weathering. Pedotransfer functions indicate a fertile soil system, but sodicity may have limited some plant growth. Paleosol bulk geochemical proxies used to estimate paleoprecipitation (733–944 mm/yr), are higher than published estimates of 250–700 mm/yr using δD values of lipid biomarkers.

Bed II is a critical part of early Pleistocene Olduvai Gorge, Tanzania. Its deposits include transitions from humid to more arid conditions (with associated faunal changes), from Homo habilis to erectus, and from Oldowan to Acheulean technology. Bed II (~ 1.8–1.2 Ma) is stratigraphically and environmentally complex, with facies changes, faulting, and unconformities, making site-to-site correlation over the ~ 20 km of exposure difficult. Bed II tuffs are thinner, less evenly preserved, and more reworked than those of Bed I. Five marker tuffs (Tuffs IIA–IID, Bird Print Tuff (BPT)), plus local tephra, were collected from multiple sites and characterized using stratigraphic position, mineral assemblage, and electron probe microanalysis of phenocryst (feldspar, hornblende, augite, titanomagnetite) and glass (where available) composition. Lowermost Bed II tuffs are dominantly nephelinitic, Middle Bed II tuffs (BPT, Tuff IIC) have basaltic components, and upper Bed II Tuff IID is trachytic. The BPT and Tuff IID are identified widely using phenocryst compositions (high-Ca plagioclase and high-Ti hornblende, respectively), though IID was originally (Hay, 1976) misidentified as Tuff IIC at Loc 91 (SHK Annexe) in the Side Gorge. This work helps establish a high-resolution basin-wide paleolandscape context for the Oldowan–Acheulean transition and helps link hominin, faunal and archaeological records.

AMS radiocarbon and OSL dating, and profiling were used to directly delimit periods of variscite production at Pico Centeno Mine 2. These results were integrated with analysis of other well-dated periods of variscite production to establish an Iberian-wide chronological framework. Variscite production at Pico Centeno Mine 2 began at ~ 5200 BC, coincident with alpine jade production or Casa Montero Iberian flint production. Variscite was only used occasionally, together with other greenstones, during the 5th and 6th millennia BC. During the 4th millennium BC, variscite use began to increase to its apogee in the first half of 3rd millennium BC when it appeared in nearly every Iberian burial site. This increase in variscite production and use coincided with decline in the popularity of alpine jade. By the end of the 3rd millennium BC, new resources began to be valued such as Asian and African Ivory, Baltic and Sicilian amber, and copper-based metal products. The variscite cycle thus started with the decline of jade in the 5th–4th millennium BC, and ended with the appearance of copper, ivory and extra-peninsular amber by the end of the 3rd millennium BC.

Argon, krypton and xenon have different solubilities in water, meaning their ratios in water are different from those in atmospheric air. This characteristic is used in a novel method to distinguish between ice bodies which originate from the compaction of snow (i.e. buried snow banks, glacial ice) vs. ice which forms from the freezing of groundwater (i.e. pingo ice). Ice which forms from the compaction of snow has gas ratios similar to atmospheric air, while ice which forms from the freezing of liquid water is expected to have gas ratios similar to air-equilibrated water. This analysis has been conducted using a spike dilution noble gas line with gas extraction conducted on-line. Samples were mixed with an aliquot of rare noble gases while being melted, then extracted gases are purified and cryogenically separated. Samples have been analysed from glacial ice, buried snow bank ice, intrusive ice, wedge ice, cave ice and two unknown ice bodies. Ice bodies which have formed from different processes have different gas ratios relative to their formation processes.