Steven L Forman
Biographic Data
| ID | 285288 |
|---|---|
| NAME | Steven L Forman |
| GIVEN NAMES | Steven L |
| FAMILY NAME | Forman |
| SIGNATURE | FORMAN S L |
| AFFILIATIONS | University of Illinois Chicago |
| ORCID | 0000-0002-1385-9194 |
| VERIFIED | Yes |
| TOTAL WORKS | 59 |
| TOTAL CITATIONS | 164 |
| AUTHOR COUNT | 59 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1987 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 7 |
The Quaternary landscapes, chronostratigraphy, and paleoenvironments of the Chalbi Desert, Kenya
The Chalbi Desert, located in eastern Africa, is a significant but overlooked archive of the Pleistocene and Holocene periods that could add insight into investigations on human evolution. We revisited southeastern Chalbi Desert landforms between the towns of Kargi and Maikona to improve the chronostratigraphy and provide paleoenvironmental context. Direct U-series and electron spin resonance dating of various fossil teeth recovered from a deflat…
Late Quaternary fluvial and aeolian depositional environments for the western Red River, Southern Great Plains, USA
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 sedime…
The formation of iron oxides and magnetic enhancement mechanisms in northern Iranian loess-paleosol sequences
Late Pleistocene Landscape and Settlement Dynamics of Portuguese Estremadura
Here we report the results of an integrated geoarchaeological survey to study Palaeolithic human settlement dynamics in the coastal region of Portuguese Estremadura. The region has been an important focus of human occupation across multiple glacial-interglacial cycles, including periods of well-documented abrupt climate instability during MIS 3 and 2. The pedestrian survey covered a roughly 10 km wide strip of land between São Pedro de Muel and P…
Late Middle Stone Age Behavior and Environments at Chaminade I (Karonga, Malawi)
The Dating of a Middle Paleolithic Blade Industry in Southern Russia and Its Relationship to the Initial Upper Paleolithic
Meteorological catalysts of dust events and particle source dynamics of affected soils during the 1930s Dust Bowl drought, Southern High Plains, USA
Mineral dust aerosols are a key component of the Earth system and a growing public health concern under climate change, as levels of dustiness increase. The Great Plains in the USA is particularly vulnerable to dust episodes, but land-atmosphere interactions contributing to large-scale dust transport are poorly constrained. This study compiled one of the longest quantitative, spatially-comprehensive records of dust events in the core Dust Bowl re…
Late Quaternary loess and soils on uplands in the Canyonlands and Mesa Verde areas, Utah and Colorado
Thin loess deposits on the uplands of the southeastern Colorado Plateau have previously not been well studied. We sampled deposits and soils from trenches on Hatch Point (HP) mesa near Canyonlands National Park, Utah, and from two outcrops in Mesa Verde National Park, Colorado. At HP, the oldest buried unit yielded 2 optically stimulated luminescence (OSL) ages of 10,370 and 7555 yr; the middle unit yielded 10 OSL ages from 6220 to 1385 yr; and t…
Eolian processes and heterogeneous dust emissivity during the 1930s Dust Bowl Drought and implications for projected 21st-century megadroughts
The 1930s Dust Bowl Drought on the US Great Plains was an environmental crisis with failure of agricultural systems, landscape denudation, and elevated atmospheric dust loads. Poor agricultural practices were implicated for triggering widespread eolian erosion and heightened dust emissions, but this assumption is called into question. This study classified land surface changes in southwest Kansas from aerial images taken in 1936 and 1939 to infer…
Optically Stimulated Luminescence Dating and the Peopling of the Americas
The measurement of time is a critical parameter in archaeology and particularly in evaluating the timing of the peopling of the Americas. New geochronometers, like optically stimulated luminescence
Late Quaternary environments of the Waco Mammoth site, Texas USA
The Waco Mammoth Site (WMS) in central Texas contains the remains of the largest mammoth herd ( Mammuthus columbi ) in North America that died in a single catastrophic event. Most mammoths at the site died on a gravel bar of the ancient Bosque River adjacent to a collapsing tributary wall. However, the timing and cause of death of the 26 mammoths documented to date are controversial. The objectives of this research are to: describe and interpret …
Lakeside View
Throughout the Holocene, Lake Turkana has been subject to drastic changes in lake levels and the subsistence strategies people employ to survive in this hot and arid region. In this paper, we reconstruct the position of the lake during the Holocene within a paleoclimatic context. Atmospheric forcing mechanisms are discussed in order to contextualize the broader landscape changes occurring in eastern Africa over the last 12,000 years. The Holocene…
Kostenki 1 and the early Upper Paleolithic of Eastern Europe
Optical ages on loess derived from outwash surfaces constrain the advance of the Laurentide Ice Sheet out of the Lake Superior Basin, USA
We present textural and thickness data on loess from 125 upland sites in west-central Wisconsin, which confirm that most of this loess was derived from the sandy outwash surfaces of the Chippewa River and its tributaries, which drained the Chippewa Lobe of the Laurentide front during the Wisconsin glaciation (MIS 2). On bedrock uplands southeast of the widest outwash surfaces in the Chippewa River valley, this loess attains thicknesses > 5 m. OSL…
Renewed Geoarchaeological Investigations of Mwanganda's Village (Elephant Butchery Site), Karonga, Malawi
The site of Mwanganda's Village, located along a paleochannel in northern Malawi, is one of only a few sites that have characterized the Middle Stone Age (MSA) of Malawi for decades (Clark & Haynes, ; Clark et al., ; Kaufulu, ). The Malawi Earlier‐Middle Stone Age Project has re‐examined the site using new mapping and chronometric tools in order to reinterpret the site's significance within the context of current debates surrounding human origins…
Late Quaternary alluvial history of the middle Owl Creek drainage basin in central Texas
Geological evidence for a drought episode in the western Pampas (Argentina, South America) during the early–mid 20th century
Drought episodes during the early–mid 20th century were recognized and described in several places around the world, with extreme dry conditions and widespread landscape denudation, like during the famous ‘Dust Bowl’ in North America. However, there is scant documentation of droughts in southern South America, particularly from the Pampas, and none based on the geological record. In this article, we provide clear evidence of aeolian reactivation …
Geoarchaeological and Bioarchaeological Studies at Mira, an Early Upper Paleolithic Site in the Lower Dnepr Valley, Ukraine
New geoarchaeological and bioarcheological research was undertaken at the open‐air site of Mira, which is buried in deposits of the Second Terrace of the Dnepr River, roughly 15 km downstream from the city of Zaporozhye in Ukraine. Previous excavation of the site revealed two occupation layers dating to ∼32,000 cal BP. The lower layer (II/2) yielded bladelets similar to those of the early Gravettian, while the upper layer (I) contained traces of …
The OSL chronology of eolian sand deposition in a perched dune field along the northwestern shore of Lower Michigan
Extensive coastal dunes occur in the Great Lakes region of North America, including northwestern Michigan where some are perched on high (~ 100 m) bluffs. This study focuses on such a system at Arcadia Dunes and is the first to systematically generate optical ages from stratigraphic sections containing buried soils. Dune growth began ca. 4.5 ka during the Nipissing high lake stand and continued episodically thereafter, with periods of increased s…
Differential Temporal and Spatial Preservation of Archaeological Sites in a Great Lakes Coastal Zone
Analysis of regional site taphonomy that incorporates depositional and postdepositional histories has become increasingly important in understanding the nature of preserved site populations and the strategies necessary for their discovery. We applied a systematic archival and field strategy directed at understanding such taphonomic processes in the coastal sand dunes of the northern and eastern Lake Michigan basin, and coupled these with a tactic…
Holocene eolian activation as a proxy for broad-scale landscape change on the Gila River Indian Community, Arizona
Eolian sediments are common within the middle Gila River Valley, southern Arizona, and reflect variability in eolian and fluvial processes during the late Holocene. This study focuses on deciphering the stratigraphic record of eolian deposition and associated luminescence dating of quartz extracts by single aliquot regeneration (SAR) protocols. Stratigraphic assessment coupled with luminescence ages indicates that there are four broad eolian depo…
The Buttermilk Creek Complex and the Origins of Clovis at the Debra L. Friedkin Site, Texas
A large artifact assemblage dating to 15,000 years ago lies beneath a Clovis assemblage in central Texas.
New insights on Illinoian deglaciation from deposits of Glacial Lake Quincy, central Indiana
The deposits of Glacial Lake Quincy overlie a diamicton associated with the classically defined Illinoian limit in central Indiana. This lake covered at least 180 km 2 with a depth of > 20 m and developed when the Illinoian ice sheet retreated 15 km from the maximum limit, causing lake impoundment against Devore Ridge. Overflow from Glacial Lake Quincy eroded across the ridge forming a number of steeped-walled outlets. A section along Mill Creek …
Paleoenvironmental and archaeological investigations at Qinghai Lake, western China
Variability of Lake Michigan water level during the past 1000 years reconstructed through optical dating of a coastal strandplain
Post Nipissing-phase strandplains of the Great Lakes reflect late-Holocene water levels that are linked to climate variability, glacial isostasy, and changes in basin hydrology. This study examines a strandplain sequence at Bailey’s Harbor, Door County, Wisconsin, along Lake Michigan, which contains a record of water-level variations during the past 1000 years, following the separation of the Lake Michigan-Huron basin from the Lake Superior basin…
From the Bay of Naples to the River Don
A severe centennial-scale drought in midcontinental North America 4200 years ago and apparent global linkages
We present evidence from a variety of physical and biological proxies for a severe drought that affected the mid-continent of North America between 4.1 and 4.3 ka. Rapid climate changes associated with the event had large and widespread ecological effects, including dune reactivation, forest fires and long-term changes in forest composition, highlighting a clear ecological vulnerability to similar future changes. Drought is also documented in the…
Renewed Geoarchaeological Investigations of Mwanganda's Village (Elephant Butchery Site), Karonga, Malawi
The site of Mwanganda's Village, located along a paleochannel in northern Malawi, is one of only a few sites that have characterized the Middle Stone Age (MSA) of Malawi for decades (Clark & Haynes, ; Clark et al., ; Kaufulu, ). The Malawi Earlier‐Middle Stone Age Project has re‐examined the site using new mapping and chronometric tools in order to reinterpret the site's significance within the context of current debates surrounding human origins…
Kostenki 1 and the early Upper Paleolithic of Eastern Europe
Lakeside View
Throughout the Holocene, Lake Turkana has been subject to drastic changes in lake levels and the subsistence strategies people employ to survive in this hot and arid region. In this paper, we reconstruct the position of the lake during the Holocene within a paleoclimatic context. Atmospheric forcing mechanisms are discussed in order to contextualize the broader landscape changes occurring in eastern Africa over the last 12,000 years. The Holocene…
Geoarchaeology of the Kostenki–Borshchevo sites, Don River Valley, Russia
The Kostenki–Borshchevo localities include 26 Upper Paleolithic sites on the first and second terraces along the west bank of the Don River, near Voronezh on the central East European Plain. Geoarchaeological research from 2001 through 2004 focused on sites Kostenki 1, 12, and 14, with additional work at Kostenki 11 and 16, and Borshchevo 5. The strata are grouped into three units (bottom up): Unit 1, > 50 ka, consists of coarse alluvium (represe…
Geoarchaeological and Bioarchaeological Studies at Mira, an Early Upper Paleolithic Site in the Lower Dnepr Valley, Ukraine
New geoarchaeological and bioarcheological research was undertaken at the open‐air site of Mira, which is buried in deposits of the Second Terrace of the Dnepr River, roughly 15 km downstream from the city of Zaporozhye in Ukraine. Previous excavation of the site revealed two occupation layers dating to ∼32,000 cal BP. The lower layer (II/2) yielded bladelets similar to those of the early Gravettian, while the upper layer (I) contained traces of …
Late Middle Stone Age Behavior and Environments at Chaminade I (Karonga, Malawi)
Geoarchaeological investigations at the Topper and Big Pine Tree sites, Allendale County, South Carolina
Stratigraphic and geochronological context of human habitation along the Galana River, Kenya
Geoarchaeological investigations along the Galana River, eastern Kenya, document a pattern of channel aggradation and then degradation from the Middle to Late Holocene. Archaeological occupations at six sites in fluvial terraces along a ̃100 km stretch of the Galana River in Tsavo East National Park correspond with fluvial aggradation beginning ca. 6000 years ago. Artifact analyses indicate that the inhabitants of these sites utilized ceramics an…
The Dating of a Middle Paleolithic Blade Industry in Southern Russia and Its Relationship to the Initial Upper Paleolithic
Aeolian sand depositional records from western Nebraska
The Great Plains is dominated by presently stabilized dune fields that are indicators of extreme drought in the late Holocene. This study focused on deciphering the timing of reactivation of dunes in western Nebraska. Stratigraphy adjacent to dune-dammed lakes reveals aeolian sand separated by palaeosols, indicating mobilization of aeolian sand followed by landscape stability. The chronology of aeolian-sand depositional events is constrained usin…
Coastal wetlands and the Neanderthal settlement of Portuguese Estremadura
Coastal wetlands are ecotone settings that offer diverse sets of resources for human exploitation, yet evidence for Pleistocene occupation rarely preserves due to recent postglacial sea‐level rise. During an ongoing geoarchaeological survey of Portuguese Estremadura we identified uplifted Pleistocene sediments that record coastal features including raised beaches, tidal channels, muds, peat, and coastal dunes. Stratified concentrations of Middle …
Variability of Lake Michigan water level during the past 1000 years reconstructed through optical dating of a coastal strandplain
Post Nipissing-phase strandplains of the Great Lakes reflect late-Holocene water levels that are linked to climate variability, glacial isostasy, and changes in basin hydrology. This study examines a strandplain sequence at Bailey’s Harbor, Door County, Wisconsin, along Lake Michigan, which contains a record of water-level variations during the past 1000 years, following the separation of the Lake Michigan-Huron basin from the Lake Superior basin…
Geoarchaeology of the Boca Negra Wash Area, Albuquerque Basin, New Mexico, USA
Dozens of Paleoindian sites, including the Boca Negra Wash (BNW) Folsom site (LA 124474), are scattered across a basalt plateau (the West Mesa) on the western side of the Albuquerque Basin, and adjacent uplands. The BNW site, like many others in the area, is located near a small ( ̃60 × 90 m) playa basin that formed in a depression on the basalt surface and was subsequently covered by an eolian sand sheet (Unit 1) dated by OSL to ̃23,000 yr B.P. …
Meteorological catalysts of dust events and particle source dynamics of affected soils during the 1930s Dust Bowl drought, Southern High Plains, USA
Mineral dust aerosols are a key component of the Earth system and a growing public health concern under climate change, as levels of dustiness increase. The Great Plains in the USA is particularly vulnerable to dust episodes, but land-atmosphere interactions contributing to large-scale dust transport are poorly constrained. This study compiled one of the longest quantitative, spatially-comprehensive records of dust events in the core Dust Bowl re…
Eolian processes and heterogeneous dust emissivity during the 1930s Dust Bowl Drought and implications for projected 21st-century megadroughts
The 1930s Dust Bowl Drought on the US Great Plains was an environmental crisis with failure of agricultural systems, landscape denudation, and elevated atmospheric dust loads. Poor agricultural practices were implicated for triggering widespread eolian erosion and heightened dust emissions, but this assumption is called into question. This study classified land surface changes in southwest Kansas from aerial images taken in 1936 and 1939 to infer…
Differential Temporal and Spatial Preservation of Archaeological Sites in a Great Lakes Coastal Zone
Analysis of regional site taphonomy that incorporates depositional and postdepositional histories has become increasingly important in understanding the nature of preserved site populations and the strategies necessary for their discovery. We applied a systematic archival and field strategy directed at understanding such taphonomic processes in the coastal sand dunes of the northern and eastern Lake Michigan basin, and coupled these with a tactic…
Changes in glacier extent on north Novaya Zemlya in the twentieth century
Glacier retreat on north Novaya Zemlya for the past century was documented by registering glacier terminus positions from expedition and topographic maps and remotely sensed images. Recession of tidewater calving glaciers on north Novaya Zemlya in the first half of the twentieth century was relatively rapid (>300 m yr -1 ), consistent with post-‘Little Ice Age’ warming documented by a 122-year instrumental record from Malye Karmakuly. The glacier…
Late Weichselian and Holocene Relative Sea-level History of Bröggerhalvöya, Spitsbergen
Radiocarbon-dated whalebones from raised beaches record a relative sea-level history for Bröggerhalvöya, western Spitsbergen that suggest a two-step deglaciation on Svalbard at the end of the late Weichselian glaciation. The late Weichselian marine limit was reached at about 13,000 yr B.P. and was followed by relatively slow emergence until about 10,000 yr B.P. either in response to ice unloading in the Barents Sea, initial retreat of local fjord…
Applications and limitations of thermoluminescence to date quaternary sediments
Late Pleistocene chronology of loess deposition near Luochuan, China
Loess near Luochuan was sampled for thermoluminescence (TL) dating simultaneously with magnetic susceptibility measurements to provide the first independent age estimates on a susceptibility record from the Loess Plateau of China. TL age estimates on late Pleistocene loess (L1) are stratigraphically consistent with no statistical difference in TL ages by the total or partial bleach techniques or by measuring ultraviolet or green wavelengths in th…
Late Weichselian Glacier Retreat in Kongsfjorden, West Spitsbergen, Svalbard
The chronology of Late Weichselian to Holocene deglaciation of Kongsfjorden, west Spitsbergen has been reconstructed based on the geomorphic and stratigraphic record of ice retreat, relative sea-level relationships, and 14 C dating of associated marine organic materials. The seaward extent of glacial drift and fjord bathymetry constrain a secure reconstruction for the ice sheet near the mouth of the fjord at ca. 13,000 yr B.P., but do not rule ou…
Timing of Late Quaternary Glaciations in the Western United States Based on the Age of Loess on the Eastern Snake River Plain, Idaho
The most viable sources for ubiquitous loess deposits on the eastern Snake River Plain, Idaho are aggraded river valleys, active alluvial fans, and fluctuating pluvial lake margins associated with regional late Pleistocene glaciation of the northern Rocky Mountains. Stratigraphic studies on the Idaho National Engineering Laboratory document two distinct loess deposits, separated by a well-developed paleosol, resting on basaltic lava. Baked sedime…
Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska
Pleistocene glacial-estuarine sediment deposited in an intertidal environment of northeastern Bristol Bay, southwestern Alaska, was dated using a variety of approaches, including infrared stimulated and thermoluminescence (IRSL and TL) techniques. Analysis of modern and 14 C-dated Holocene tide-flat mud demonstrates that the bulk of sediment in this environment is reset by solar radiation, thereby lending confidence to ages obtained from similar …
Late Quaternary Geology and Geochronology of Diring Yuriakh, An Early Paleolithic Site in Central Siberia
Diring Yuriakh, an archaeological site on the highest terrace of the Lena River in subarctic eastern Siberia, provides evidence for the oldest and northern-most Early Paleolithic occupation in Asia. Stratigraphic and sedimentological studies at the site show that artifacts occur on a single eolian deflation surface that is underlain by fluvial sediments with inset cryogenic sand wedges and overlain by eolian deposits. Thermoluminescence ages on t…
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Holocene Paleohydrology and Paleoclimate at Treeline, North-Central Russia, Inferred from Oxygen Isotope Records in Lake Sediment Cellulose
Lake-water oxygen-isotope histories for three lakes in northern Russia, derived from the cellulose oxygen-isotope stratigraphies of sediment cores, provide the basis for preliminary reconstruction of Holocene paleohydrology in two regions along the boreal treeline. Deconvolution of shifting precipitation δ 18 O from secondary evaporative isotopic enrichment is aided by knowledge of the distribution of isotopes in modern precipitation, the isotopi…
Holocene Treeline History and Climate Change Across Northern Eurasia
Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern …
The Holocene occurrence of reindeer on Franz Josef Land, Russia
Reindeer are absent historically on the high Arctic islands of Franz Josef Land, Russia. However, shed antlers are common on unglaciated forelands on Hooker, Scot Keltie and Alexandra Land Islands in the archipelago. Radiocarbon dating of 19 new antler remains combined with seven ages reported previously demonstrate the presence of reindeer between c. >6400 and 1300 cal. BP. Reindeer probably occupied Franz Josef Land for much of the Holocene ref…
The Last Interglacial to Glacial Transition, Togiak Bay, Southwestern Alaska
An 18-m-high coastal bluff at Togiak Bay (northwestern Bristol Bay, southwestern Alaska) exposes marine, lacustrine, fluvial, glacial, volcanic, and organic deposits that record the ∼50,000-year-long transition from the peak of the last interglaciation to the early Wisconsin glaciation. The base of the section is dominated by stratified sand and silt extending up to 4.3 m above sea level; marine diatoms are present, and pollen assemblages are cha…
Holocene Relative Sea-Level History of Novaya Zemlya, Russia, and Implications for Late Weichselian Ice-Sheet Loading
We present six new radiocarbon-dated emergence curves that provide a detailed record of postglacial emergence of northern Novaya Zemlya and ages which constrain the emergence of Vaygach Island in the southern archipelago. Radiocarbon ages on Hiatella sp. from a lateral moraine in Russkaya Gavan' and abundances of foraminifea in a marine core from Nordenskiold Bay, 300 km south of our study area, indicate that coastal deglaciation occurred prior t…
Age of the Cutler Dam Alloformation (Late Pleistocene), Bonneville Basin, Utah
Luminescence geochronology, especially infrared stimulated luminescence analyses on marsh mud, shows that a relatively deep lake reached its peak (∼1340 m above sea level) in the Bonneville basin 59,000±5000 yr ago. The age is consistent with nonfinite 14 C ages and with amino acid geochronology on ostracodes. The Cutler Dam Alloformation was deposited during this lake cycle, which, like the subsequent Bonneville lake cycle, appears to have reach…
Changes in glacier extent on north Novaya Zemlya in the twentieth century
Glacier retreat on north Novaya Zemlya for the past century was documented by registering glacier terminus positions from expedition and topographic maps and remotely sensed images. Recession of tidewater calving glaciers on north Novaya Zemlya in the first half of the twentieth century was relatively rapid (>300 m yr -1 ), consistent with post-‘Little Ice Age’ warming documented by a 122-year instrumental record from Malye Karmakuly. The glacier…
Late Quaternary Stratigraphy, Glacial Limits, and Paleoenvironments of the Marresale Area, Western Yamal Peninsula, Russia
Stratigraphic records from coastal cliff sections near the Marresale Station on the Yamal Peninsula, Russia, yield new insight on ice-sheet dynamics and paleoenvironments for northern Eurasia. Field studies identify nine informal stratigraphic units from oldest to youngest (the Marresale formation, Labsuyakha sand, Kara diamicton, Varjakha peat and silt, Oleny sand, Baidarata sand, Betula horizon, Nenets peat, and Chum sand) that show a single gl…
Optically stimulated luminescence dating of late Holocene raised strandplain sequences adjacent to Lakes Michigan and Superior, Upper Peninsula, Michigan, USA
This study evaluates the accuracy of optically stimulated luminescence to date well-preserved strandline sequences at Manistique/Thompson bay (Lake Michigan), and Tahquamenon and Grand Traverse Bays (Lake Superior) that span the past ∼4500 yr. The single aliquot regeneration (SAR) method is applied to produce absolute ages for littoral and eolian sediments. SAR ages are compared against AMS and conventional 14 C ages on swale organics. Modern lit…
A severe centennial-scale drought in midcontinental North America 4200 years ago and apparent global linkages
We present evidence from a variety of physical and biological proxies for a severe drought that affected the mid-continent of North America between 4.1 and 4.3 ka. Rapid climate changes associated with the event had large and widespread ecological effects, including dune reactivation, forest fires and long-term changes in forest composition, highlighting a clear ecological vulnerability to similar future changes. Drought is also documented in the…
Aeolian sand depositional records from western Nebraska
The Great Plains is dominated by presently stabilized dune fields that are indicators of extreme drought in the late Holocene. This study focused on deciphering the timing of reactivation of dunes in western Nebraska. Stratigraphy adjacent to dune-dammed lakes reveals aeolian sand separated by palaeosols, indicating mobilization of aeolian sand followed by landscape stability. The chronology of aeolian-sand depositional events is constrained usin…
Textbook Publishing
Imagine an ecosystem in which the major organisms are faculty, students, textbook publishers, and bookstores. As producers, consumers, and decomposers, they circulate the nutrients of higher education up and down the food chain. The system has sustained a long-term equilibrium, with change coming in gradual, evolutionary form. But in recent years, some of the system's core conditions have changed, disturbing that equilibrium. Some observers see a…
Episodic Late Holocene dune movements on the sand-sheet area, Great Sand Dunes National Park and Preserve, San Luis Valley, Colorado, USA
The Great Sand Dunes National Park and Preserve (GSDNPP) in the San Luis Valley, Colorado, contains a variety of eolian landforms that reflect Holocene drought variability. The most spectacular is a dune mass banked against the Sangre de Cristo Mountains, which is fronted by an extensive sand sheet with stabilized parabolic dunes. Stratigraphic exposures of parabolic dunes and associated luminescence dating of quartz grains by single-aliquot rege…
Middle Weichselian environments on western Yamal Peninsula, Kara Sea based on pollen records
Pollen data from two sections from a coastal cliff on the western Yamal Peninsula (69 ° 43.27′N, 66 ° 48.80′E) document the environmental history during the Karginsky (Middle Weichselian) interstadial. Low pollen concentrations, high amounts of redeposited pollen, and relatively high presence of Artemisia pollen characterize sediments deposited at about 33,000 14 C yr B.P. Grass-sedge plant associations with few other herbs occupied the area duri…
Geoarchaeology of the Boca Negra Wash Area, Albuquerque Basin, New Mexico, USA
Dozens of Paleoindian sites, including the Boca Negra Wash (BNW) Folsom site (LA 124474), are scattered across a basalt plateau (the West Mesa) on the western side of the Albuquerque Basin, and adjacent uplands. The BNW site, like many others in the area, is located near a small ( ̃60 × 90 m) playa basin that formed in a depression on the basalt surface and was subsequently covered by an eolian sand sheet (Unit 1) dated by OSL to ̃23,000 yr B.P. …
East African megadroughts between 135 and 75 thousand years ago and bearing on early-modern human origins
The environmental backdrop to the evolution and spread of early Homo sapiens in East Africa is known mainly from isolated outcrops and distant marine sediment cores. Here we present results from new scientific drill cores from Lake Malawi, the first long and continuous, high-fidelity records of tropical climate change from the continent itself. Our record shows periods of severe aridity between 135 and 75 thousand years (kyr) ago, when the lake's…
Early Upper Paleolithic in Eastern Europe and Implications for the Dispersal of Modern Humans
Radiocarbon and optically stimulated luminescence dating and magnetic stratigraphy indicate Upper Paleolithic occupation—probably representing modern humans—at archaeological sites on the Don River in Russia 45,000 to 42,000 years ago. The oldest levels at Kostenki underlie a volcanic ash horizon identified as the Campanian Ignimbrite Y5 tephra that is dated elsewhere to about 40,000 years ago. The occupation layers contain bone and ivory artifac…
Geology and Paleoclimatology Research (49 works) · Geography (42 works) · Geology (31 works) · Paleontology (30 works) · Archaeology (28 works) · Physical geography (28 works) · Geology (27 works) · Holocene (23 works) · Geomorphology (22 works) · Archaeology and ancient environmental studies (21 works)