ABSTRACTThe highest cycle of post‐Lake Bonneville Great Salt Lake in the Bonneville basin, Utah, USA, was thought for many years to have formed the ‘Gilbert shoreline’ (quotation marks indicate lack of scientific support). Mapping of the ‘shoreline’ is not reproducible and the concept has multiple problems, including that the ‘shoreline’ cannot be correlated with the well‐documented major rise of Great Salt Lake during the terminal Pleistocene. To avoid confusion, we propose abandoning the name Gilbert, which previously had been applied informally to both the hypothetical shoreline and lake cycle, and instead we use the name Currey cycle for the lake rise. During the Younger Dryas Currey cycle, Great Salt Lake became fresh to brackish about 12 700 cal a bp, and rose roughly 15 m higher than the modern lake. The end of the Currey cycle marked the beginning of extensive human occupation of the Old River Bed inland delta.

Abstract Mollusk and ostracode assemblages from the distal Old River Bed delta (ORBD) contribute to our understanding of the Lake Bonneville basin Pleistocene-Holocene transition (PHT) wetland and human presence on the ORBD (ca. 13,000–7500 cal yr BP). Located on U.S. Air Force-managed lands of the Great Salt Lake Desert (GSLD) in western Utah, USA, the area provided 30 samples from 12 localities. The biological assemblages and the potential water sources using 87Sr/86Sr analyses showed wetland expansion and contraction across the PHT, including the Younger-Dryas Chronozone (YDC). The record reflects cold, freshwater conditions, which is uncharacteristic of the Great Salt Lake Desert, after recession of Lake Bonneville. Lymnaea stagnalis jugularis, Cytherissa lacustris, and possibly Candona sp. cf. C. adunca, an endemic and extinct species only reported from Lake Bonneville, suggest cold-water environments. Between 13,000–12,400 cal yr BP, a shallow lake formed, referred to as the Old River Bed delta lake, fed by Lake Gunnison, as shown by 87Sr/86Sr ratios of 0.71024–0.71063 in mollusk fossils collected at the ORBD, characteristic of the Sevier basin. These findings add paleoenvironmental context to the long-term use of the ORBD by humans in constantly changing wetland habitats between 13,000–9500 cal yr BP.

This article briefly explores the archaeological signatures of Early through Late Holocene resource use and hunter-gatherer settlement patterns near Emerson Lake aboard the Marine Corps Air Ground Combat Center. Investigations of 156 localities along a linear belt of probable plant biomass modeled through Normalized Difference Vegetation Index assessments registered larger, richer, and more diverse assemblages containing significantly higher frequencies of resource-processing artifacts, such as flake took and ground stone, nearer this belt than predicted by random distribution, suggesting that hunter-gatherer encampments, reflecting the utilization of recurring abundant seasonal biotic patches, targeted this belt. However, other than upticks in processing artifact numbers and proximity to the belt during the 1,000 years prior to European contact, archaeological assemblage profiles remain comparatively constant, implying little deviation in the way local hunter-gatherers utilized and settled around this landscape throughout the Holocene.

ABSTRACTWe present a novel approach to developing a unified radiocarbon-based chronology for multiple sediment cores from a location where radiocarbon dating is challenging. We used 36 radiocarbon ages from eight terminal Pleistocene and Holocene sediment cores with correlated stratigraphies. Stratigraphic correlation was accomplished using a combination of high-resolution photography, high-resolution X-ray fluorescence-based elemental composition data, and volcanic tephra identification. Results show that despite problems associated with potential contamination or radiocarbon reservoir effect, a useful age-depth model has been created for the correlated lacustrine sections of these eight sediment cores, providing chronological controls for future paleoenvironmental analyses of the cores.

Current archaeological research on cultigens emphasizes the protracted and intimate human interactions with wild species that defined paths to domestication and, with certain plants, profoundly impacted humanity. Tobacco arguably has had more impact on global patterns in history than any other psychoactive substance, but how deep its cultural ties extend has been widely debated. Excavations at the Wishbone site, directed at the hearth-side activities of the early inhabitants of North America's desert west, have uncovered evidence for human tobacco use approximately 12,300 years ago, 9,000 years earlier than previously documented. Here we detail the preservation context of the site, discuss its cultural affiliation and suggest ways that the tobacco may have been used. The find has implications for our understanding of deep-time human use of intoxicants and its sociocultural intersection with food crop domestication.

Limited excavations at Nangara-Komba Shelter along the northern margin of the Congo Basin have recovered evidence for intermittent and at times intensive human visits beginning approximately 5100 cal. BC. Numerous rock art panels adorn the shelter’s walls and ceramics appear to have initially been brought to the site between 1050 and 900 cal. BC, if not earlier. Charred Canarium schweinfurthii endocarp fragments were collected in all stratigraphic aggregates and reflect the use of canarium for food, fuel and/or medicinal purposes during the middle and late Holocene. Abundant quartz and quartzite artefacts occur throughout the deposits and mark a continuous and stable microlithic tradition. The site was used only by foraging groups who ultimately interacted with Bantu and later Ubangian farmers and possibly smelters. Nangara-Komba represents a sheltered context where the use of lithic tools appears to have persisted well into the late Holocene and is the only known site in the Central African Republic and Sangha River Interval with episodic occupations spanning the past 7000 years.

Recently, Lupo et al. (2015, 2018) reported novel data on the nature and timing of late Holocene human settlement and iron production in the northern Congo Basin rain forest, southern Central African Republic. This paper expands those data by presenting new archaeological and chronological information discovered in field investigations conducted in 2017-2018. Twenty-five archaeological sites were identified and radiocarbon dates from 14 signal human habitation over some 1900 years. Together with the previously reported investigations a diverse suite of sites has been identified, including slag mounds, ceramic scatters, habitation sites and the only documented series of iron ore quarries in the Central African forest. Cumulatively, the results of radiocarbon assay of charcoal samples from 32 sites indicate nearly continuous human activity in the Lobaye River Basin over the past 2300 years. Among others, these data: 1) indicate, for the first time, an Early Iron Age interval in the region with evidence of iron production; 2) include multiple calibrated age estimates on sites/components dating within the c. 1400-800 BP hiatus in human occupations reported elsewhere in Central Africa forests; and 3) afford a number of additional radiocarbon age estimates that fall during the Late Iron Age increase in human use of the forest reported in neighbouring contexts.

Archaeological surveys and excavations in the NGotto Forest Reserve, Central African Republic, discovered 98 artefact concentrations or cultural features that included ceramic scatters, iron-ore mines and iron smelting features. These investigations provide, for the first time, a series of radiocarbon dates that chronicle the timing and context of prehistoric occupation along the northern margin of the Congo Basin rain forest in the Central African Republic. Thirty-three age estimates from 19 sites are distributed throughout the late Holocene and together document 2500 years of occupations. A number of the dates are from iron extraction and processing features that reflect extensive pre-colonial use of the area between about AD 1750 and 1840, while a radiocarbon date of 217937 BP in direct association with pottery signals settlement by ceramic-bearing peoples perhaps as early as 350 cal. BC. Three radiocarbon dates from two sites reflect occupations during the purported hiatus and reduction in regional forest populations c. 1400-800 BP and five dates from four additional sites in southern Central African Republic rain forests also fall during this interval. In concert with scrutiny of summed probability distributions and potential artefacts embedded within the radiocarbon calibration curve, the number of these dates question the reality of this occupational hiatus, at least in the north-central Congo Basin.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Environmental Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Modern Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Modern Fauna and Flora . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Environments of the Latest Pleistocene and Holocene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Early Holocene (11,700–8500 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Middle Holocene (8500–3800 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Late Holocene (3800 to present) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Cultural Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Prehistoric Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Paleoindian Period (14,500–12,800 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Paleoarchaic Period (12,800–7800 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Post-Mazama Period (7800–5700 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Early Archaic Period (5700–3800 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Middle Archaic Period (3800–1300 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Late Archaic Period (1300–600 cal b.p.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 Terminal Prehistoric Period (600 cal b.p. to Contact) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Ethnographic Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Subsistence and Settlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Seasonal Round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Intergroup Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Social Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Field and Laboratory Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Field Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Surface Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Subsurface Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Mechanical Trenching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Augering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Excavation Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Laboratory and Analytical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Artifact Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Faunal Remains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Special Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Curation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Chronological Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Projectile Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Great Basin Stemmed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Northern Side-notched . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Humboldt Concave Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 Gatecliff Split Stem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 Contracting Stem Dart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 2018 MCGUIRE ET AL.: ENVIRONMENT & LAND USE IN THE BLACK ROCK DESERT 3 Elko Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 Lanceolate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 Rose Spring and Eastgate Series (“Rosegate”) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 Small Stemmed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 Desert Side-notched . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 Cottonwood Triangular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 Other Types (Dart Sized, Arrow Sized, Indeterminate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 Shell Beads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5056 Glass, Stone, and Bone Beads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 Radiocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 Building Spatio-temporal Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 26HU1830 Site Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 Field Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 Site Structure and Chronology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 Surface Artifact Loci . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 Surface Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68 Subsurface Site Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68 Other Site Contexts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78 Component Definition and Chronological Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78 Assemblage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 Middle Archaic Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 Late Archaic A Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89 Noncomponent Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90 Site Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90 26HU1876 Site Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92 Field Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92 Site Structure and Chronology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 Grid 1 Area . . . . . . . . . . . . . . . . . . . . .

Considerable prior research has focused on the interconnected pluvial basins of Owens Lake and Searles Lake, resulting in a long record of paleohydrological change in the lower Owens River system. However, the published record is poorly resolved or contradictory for the period encompassing the terminal Pleistocene (22,000 to 11,600 cal BP) and early Holocene (11,600–8200 cal BP). This has resulted in conflicting interpretations about the timing of lacustrine high stands within the intermediate basin of China Lake, which harbors one of the most extensive records of early human occupation in the western Great Basin and California. Here, we report a broad range of radiocarbon-dated paleoenvironmental evidence, including lacustrine deposits and shoreline features, tufa outcrops, and mollusk, ostracode, and fish bone assemblages, as well as spring and other groundwater-related deposits (a.k.a. “black mats”) from throughout China Lake basin, its outlet, and inflow drainages. Based on 98 radiocarbon dates, we develop independent evidence for five significant lake-level oscillations between 18,000 and 13,000 cal BP, and document the persistence of groundwater-fed wetlands from the beginning of the Younger Dryas through the early Holocene (12,900–8200 cal BP); including the transition from ground-water fed lake to freshwater marsh between about 13,000 and 12,600 cal BP. Results of this study support and refine existing evidence that shows rapid, high-amplitude oscillations in the water balance of the Owens River system during the terminal Pleistocene, and suggest widespread human use of China Lake basin began during the Younger Dryas.

P erhaps the largest-scale archaeological study ever undertaken in the Great Basin, the Ruby Pipeline Project included the investigation of 566 prehistoric sites across northern Nevada.A 13,000 year record of human occupation was documented spanning the first pluvial lake settlements at the close of the last Ice Age to the rise of the Western Shoshone and Northern Paiute.This archaeological record is replete with vast obsidian quarries, upland root-gathering sites, major residential bases, specialized hunting camps, and large-scale antelope traps.We are introduced to a prehistoric world of continual change, one marked by transformed environments, shifts in settlement and subsistence structure, and even wholesale population movements.The result is a work that allows us to chronicle the initial colonization of northern Nevada, monitor the subsequent process of population growth and dispersal, document the evolution of exchange systems, and propose a compelling new version of Numic prehistory.

An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889) and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories.

This paper takes a geoarchaeological contextual approach in arguing that pavement quarries—those assay and reduction events directed at cobbles that often litter expansive desert alluvial landforms—can provide a powerful index of changing trans-Holocene settlement organization. Focusing on multiple lines of evidence—age estimates of alluvial fan surfaces, quarry technology, patination pro les, and regional toolstone consumption trends at residential sites—we explore the temporal and technological development of quarry pavement use at the National Training Center at Fort Irwin, Mojave Desert. The analysis reveals that chert pavement quarrying was in ascendance during the early portion of the Late Holocene and had a strong biface production component. This landform-based model of Holocene pavement quarry development provides support for reconstructions that envision Gypsum period hunter-gatherers as residentially stable, and as undertaking increased logistical forays during which pavement quarry procurement took place.