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In 1995, an unusually perforated femur of a juvenile cave bear was found in the Divje babe I Palaeolithic cave site in Slovenia. The supposition that it could be a flute led to heated debates. According to its archaeological context and chronostratigraphic position, if made by humans, it could only be attributed to Neanderthals. The crucial question was related to the origin of the holes. These could only have been made either by a carnivore or by human intervention. Results of experimental testing of both hypotheses do not support a carnivore origin of the holes. Furthermore, the method of artificial creation of the holes, which left no conventional traces of manufacture, was defined. Computed tomography revealed traces, which could be the result of human agency and called into serious question the origin of some features previously declared to be solely of carnivore origin. Recent musical experiments performed on a replica of the reconstructed musical instrument revealed its great musical capability. Together with some other findings from Divje babe I, the Mousterian musical instrument offers a unique insight into the Neanderthals’ symbolic behaviour and their cognitive abilities. The multidisciplinary results of comprehensive analyses of this exceptional find are first presented here together with its chronostratigraphic, palaeo-environmental, and archaeological contexts.

In the West of Ukraine, the Medzhibozh site complex includes two multi-layered open-air Lower Paleolithic sites sitting at 49°35′ N 27°42′ E, 270 m amsl. In Medzhibozh I’s lower alluvial cycle, Layer 16a yielded Paleolithic artefacts, mainly choppers, chopping tools, and flakes with little secondary modification, associated with likely fireplaces and bones with cutmarks left by early hominids inhabiting an ancient shoreline. Ursus deningeri, Stephanorhinus kirchbergensis , and other Middle Pleistocene fossils, as well as microtheriofauna, pollen, paleopedology data suggest that Layers 13—16 must predate 200 ka, but only one TL date has been done here. About 500 m away from Medzhibozh I, Medzhibozh A’s six archaeological layers were intercalated with sterile gravels, with analogous stone products, fauna, hearth relics . Since ESR can date mammalian enamel up to 2—4 Ma with 2—5 % precision, three cervid teeth from Layer 16a at Medzhibozh I and one from the Layer 1 in Medzhibozh A were dated by standard and isochron ESR. Sediment samples were analyzed by NAA to measure volumetrically averaged sedimentary dose rates. Using geological criteria, a ramped box model calculated time-averaged cosmic dose rates were determined. From Medzhibozh A, AT29’s standard LU age of 379±27 ka agreed best with ages estimated from the faunal analyses, but the isochron showed diffusional secondary U uptake, suggesting the age could be older. At Medzhibozh I, all teeth had >100 ppm U in their dentine, but enamel U ranged from 2,8 to 11,8 ppm. AT41’s isochron, which did not show secondary U uptake, suggested that the U uptake rate, p ~4 was the best uptake rate, yielding an age of 373±17 ka, which correlates with late Marine Isotope Stage (MIS) 11. Meanwhile, AT44’s age likely dates at 399±11 ka with p =4, and AT45’s at 396±13 ka with p =6, both of which correlate with mid MIS 11. Their isochrons suggested secondary diffusional U uptake had affected both teeth. All isochron analyses suggest that one secondary uptake event may have affected the entire site, likely due to immersion in U-rich water. If correct, AT29’s age makes Medzhibozh A’s hearths the oldest in the Ukraine, but more teeth from all the layers must be ESR dated and tested with coupled ESR— 230 Th/ 234 U to confirm the ages and p ’s.

Today, Bir Tarfawi, Kharga and Dakhleh Oases all sit in Egypt's hyperarid Western Desert. A dearth of naturally occurring surface water coupled with ≤ 0.1 mm/y of precipitation, and evaporation rates > 2 m/y make Bir Tarfawi uninhabitable today, while Dakhleh and Kharga depend on borehole water to support human inhabitation. Yet in scattered locations dotting the Quaternary surfaces and deposits near each oasis, Paleolithic artefacts, fossil ungulate teeth, and snails record times when surface water did exist in wetlands, small ponds, and even large lakes. At Bir Tarfawi in Marine Isotope Stages (MIS) 5, 7, and 13, wetlands or small lakes supported freshwater snails, large herbivores, and hominins. Dakhleh Oasis hosted a large lake in MIS 6 that provided a deep reliable water supply for many millennia subsequently. ESR dates on fossils and tufa dates show thriving lacustrine and terrestrial ecosystems at Dakhleh during MIS 5, 7, 9, 11, and 17, and in shorter episodes in MIS 1, 2, 3, 6, and 12. At Kharga Oasis, springs discharged along the Libyan Escarpment edge, but the water was ponded in small basins dammed within tufa deposits. These dated deposits and fossils attest that water existed there in MIS 2–11, and one spot dating to ∼ 2.3 Ma. This proxy evidence suggest that, thanks to higher rainfall and/or groundwater tables, sufficient water persisted for much of the Pleistocene, supporting food resources, like large herbivores and molluscs, to thrive and enabling hominin habitation. and activity in the Western Desert.

During the Sangamon Episode, North America occasionally experienced warm climates. At Hopwood Farm, IL, a small kettle lake filled with sediment after the Illinois Episode glaciers retreated from southern Illinois. To date those deposits, 14 mollusc samples newly collected with associated sediment from three depths at Hopwood Farm were dated by standard electron spin resonance (ESR) dating. ESR can date molluscs from ~0.5 ka to >2 Ma in age with 5-10% precision, by comparing the accumulated radiation dose with the total radiation dose rate from the mollusc and its environment. Because all molluscs contained ≤0.6 ppm U, their ages do not depend on the assumed U uptake model. Using five different species, ESR analyses for 14 mollusc subsamples from Hopwood Farm showed that Unit 3, a layer rich in lacustrine molluscs, dates at 102 ± 7 ka to 90 ± 6 ka, which correlates with Marine (Oxygen) Isotope Stage 5c-b. Thus, the period with the highest non-arboreal pollen at Hopwood also correlates with the European Brorup, Dansgaard-Oeschger Event DO 23, a time period when climates were cooling and drying somewhat over the same period.

Electron spin resonance (ESR) dating can date many materials, including hydroxyapatite in enamel and some fish scales, aragonite and calcite in corals, molluscs, some travertine and calcrete, and quartz from ash, fluvial deposits, and some flint. Dating studies using these materials have numerous potential applications in many varied Quaternary settings. ESR dating uses signals resulting from trapped charges created by radiation in crystalline solids. Ages are calculated by comparing the accumulated radiation dose in the dating sample with the internal and external radiation dose rates produced by natural radiation in and around the sample and produced by cosmic radiation. When compared to other dating techniques, age agreement has been excellent for teeth, corals, molluscs, and quartz. Recent improvements have included using a more complex modelling technique to calculate the cosmic dose rates and more detailed modelling techniques for dealing with variable external dose rates. Methods in development include using quartz from buried fluvial valleys to date geomorphic surfaces and using the signals in barnacles and benthic foraminifera for dating fossils or their associated sediment. New chronometer applications recently developed include using coral and mollusc dates to build sealevel curves and to monitor volcanic activity and tectonic uplift, using tooth and mollusc dates to assess water availability in deserts, and using isochron data to assess U uptake processes into teeth. When coupled with other geochemical and geomorphological techniques, ESR can provide the chronometric control to build paleoclimatic and other paleoenvironmental records. Many other applications are possible, from heating studies for artefacts to dating sulphates and other minerals on distant planets. (C) 2016 Elsevier B.V. All rights reserved.

In the northeastern Sahara, electron spin resonance (ESR) dating of when animals lived documents their habitability in Dakhleh Oasis, Egypt. A Middle Pleistocene paleolake(s) covered >1700 km 2 . At eastern Locality Dak348, 10 m thick, remnant lacustrine marls yielded Pleistocene fauna, rare artefacts, and plant casts. No obvious unconformity exists within these deposits. From upper horizons, a hartebeest tooth ESR dated at 195 ± 11 ka, correlates with Marine Isotope Stage (MIS) 7, while molluscs from a stratigraphically higher horizon averaged 89 ± 10 ka, correlating with MIS 5a/b. At western Locality Dak006, upslope deflation has left a temporally mixed surficial lag. Numerous lagged tooth fragments, independently dated by ESR, correlate with MIS 5 through 17. Fragments from a slope sand unit correlate with MIS stages 3 through 6. One bovid tooth associated with Younger Middle Stone Age artefacts in the base of the sand dated at 84 ± 7 ka (MIS 5a/b). Molluscs from Romano-Byzantine backdirt at a breached artesian vent dated to 8–15 ± 1 ka, suggesting that ponds formed during MIS 1 and 2. Even without well defined sedimentary contexts, ESR frequency data indicate that the oasis was habitable for herbivores during at least twelve stages in the Mid-Late Quaternary, and, therefore, likely also for humans.

G. Caton-Thompson and E. W. Gardner designated new Pleistocene cultural units at Kharga Oasis in the 1930’s: both were originally termed ‘pre-Sebilian’, but were later locally named the ‘Levalloiso-Khargan’ and ‘Khargan’ industries. High on the Bulaq scarp face, a puzzling cluster of stone ‘alignments’ was discovered in 1931–32, with a reported, but discounted, association with ‘Levalloiso-Khargan’ artefacts. Gardner excavated some features in 1933. Members of the Kharga Oasis Prehistory Project relocated ‘Site J’ in January 2011, and verified the reported Khargan associations with the features. In 2008, the project found structural features associated with Khargan artefacts in the northern Gebel Yebsa survey area, confirming earlier finds in the southern oases of Kurkur and Dungul. Evidence there, and that found in Kharga and Dakhleh oases, is now designated as the Khargan Complex. The associated built stone features of the included cultural units appear to be unique in Late Pleistocene Africa, especially at Bulaq.

ESR (electron spin resonance) can date sites that span the whole Paleolithic, but requires accurate sedimentary dose rates, especially in caves where the internal and cosmic dose rates can approach 0 mGy/yr. This study examines the sedimentary radioactivity in the upper layers at Golema Pešt, North Macedonia. Reaching > 5.5 m deep, > 21 flatly lying, silty-sandy matrix-supported gravel layers with éboulis clasts fill the cave. In Sondage 2, Layers 0–5 contained many hearths and yielded thousands of bones and teeth, many from ungulates. In Layers 2-5a sat thousands of lithics and small tools, many made on tiny quartz crystals. Layers 2c-6 have Mousterian assemblages with denticulates, notched tools, Levallois cores and flakes. To measure the volumetrically averaged sedimentary dose rates for ungulate teeth dated by ESR from Sondage 2, 66 sediment samples were analyzed by NAA. Adding éboulis, calcined bone, and charcoal associated with the hearths lowered the sedimentary dose rates or left them unchanged. In Layer 2 at 198 cm below the cave datum, the Campanian Ignimbrite (CI) cryptotephra occurred, where it caused abnormally high sedimentary U, Th, and K concentrations and dose rates. Since the CI tephra lay 28–30 cm above AT77, a tooth dated from Layer 3, using time- and volumetrically averaging increased AT77’s sedimentary dose rate by 32%, and dropped its calculated age by 25%. Analyzing the sedimentary compositions at every 2 cm in Layers 0–2 yielded a highly detailed stratigraphy that reduced the uncertainty in the sedimentary dose rates and the ESR ages, but more detailed geochemical analyses must be completed within the lower layers in Sondage 2.

Tectonic movements among the African, Arabian, Aegean, and Anatolian Plates have deformed the eastern Mediterranean Basin. Since the late Pliocene, these movements caused transtensional opening of the NE-trending Antakya Graben. Tectonic uplift coupled with Quaternary sealevel fluctuations has produced several stacked marine terraces along the Mediterranean coasts on the Antakya Graben. Here, molluscs from terrace deposits that sit on both Graben flanks at elevations between similar to 3 and similar to 175 m were dated using standard electron spin resonance (ESR) dating. For molluscs in situ in the terraces, the ESR ages ranged from similar to 8.3 to similar to 214 ka, but most of the dated terraces contained molluscs reworked from several earlier deposits due to later tectonic movements, sealevel fluctuations, and associated sedimentary processes. By dating in sim fossils, such as Lithophaga, within or just above the basal contacts for the marine terraces, uplift rates were calculated on both sides of the Antakya Graben. North of the Asi River, the regional uplift rate ranges from similar to 0.43 +/- 0.11 mm/yr at Samandag to as high as 2.08 +/- 0.70 mm/yr at Magaracik Dump. South of the Asi River, uplift rates range from 0.81 +/- 0.14 mm/yr at the Cliffside terrace to 2.33 +/- 0.60 mm/yr at Meydan Dump I. Rather than regional movements, however, local active normal or transtensional faults, such as the Glizene, Akin, and Sinanli Faults mainly uplifted these deposits.

Receiving

Sealevel curves are best developed on tectonically stable coastlines, like San Salvador, where eolianites preserve transgressive and regressive phases associated with Quaternary high seastands, while reef facies mark the highstands. At 11 locations around San Salvador, terrestrial molluscs ( Cerion ) from the eolianites, lagoonal bivalves ( Codakia ), and corals from the highstand deposits were dated by ESR. Volumetrically averaged sedimentary dose rates were calculated from sedimentary geochemistry and time-averaged cosmic dose rates from each sample’s current and past geologic contexts. Rice Bay Formation corals dated at 3.9 ± 0.3 to 7.1 ± 0.4 ka (OIS 1). Minimum ages for the Cockburn Town Member’s regressive phase ranged from 49 ± 6 to 75 ± 8 ka, correlating with OIS 3–4. Codakia dates showed that an OIS 5a sealevel approached modern levels at 91–78 ka. In situ corals from the Cockburn Town Reef averaged from 127 ± 6 to 138 ± 10 ka, correlating well with OIS 5e. Ages from the Reef’s rubble zones hint that some coral reefs grew as early as OIS 7, but were likely reworked during OIS 5. San Salvador preserves deposits from three mid to late Quaternary highstands above, and as many as three that closely approach, modern sealevel.

The oldest known fossil hominin in southern Asia was recovered from Hathnora in the Narmada Basin, central India in the early 1980's. Its age and taxonomic affinities, however, have remained uncertain. Current estimates place its maximum age at >236ka, but not likely older than the early middle Pleistocene. The calvaria, however, could be considerably younger. We report recent fieldwork at Hathnora and associated Quaternary type-sections that has provided new geological and archaeological insights. The portion of the exposed 'Boulder Conglomerate' within the Surajkund Formation, which forms a relict terrace and has yielded the hominin fossils, contains reworked and stylistically mixed lithic artifacts and temporally mixed fauna. Three mammalian teeth stratigraphically associated with the hominin calvaria were dated by standard electron spin resonance (ESR). Assuming an early uranium uptake (EU) model for the teeth, two samples collected from the reworked surface deposit averaged 49+/-1ka (83+/-2ka, assuming linear uptake [LU]; 196+/-7ka assuming recent uptake [RU]). Another sample recovered from freshly exposed, crossbedded gravels averaged 93+/-5ka (EU), 162+/-8ka (LU) or 407+/-21ka (RU). While linear uptake models usually provide the most accurate ages for this environment and time range, the EU ages represent the minimum possible age for fossils in the deposit. Regardless, the fossils are clearly reworked and temporally mixed. Therefore, the current data constrains the minimum possible age for the calvaria to 49+/-1ka, although it could have been reworked and deposited into the Hathnora deposit any time after 160ka (given the LU uptake ages) or earlier (given the RU ages). At Hathnora, carbonaceous clay, bivalve shells, and a bovid tooth recovered from layers belonging to the overlying Baneta Formation have yielded (14)C ages of 35.66+/-2.54cal ky BP, 24.28+/-0.39cal ky BP, and 13.15+/-0.34ky BP, respectively. Additional surveys yielded numerous lithics and fossils on the surface and within the stratigraphic sequence. At the foot of the Vindhyan Hills 2km from the river, we recovered a typologically Early Acheulean assemblage comprised of asymmetrical bifaces, large cleavers with minimal working, trihedral picks, and flake tools in fresh condition. These tools may be the oldest Acheulean in the Narmada Valley. Several lithics recovered from the Dhansi Formation may represent the first unequivocal evidence for an early Pleistocene hominin presence in India. In situ invertebrate and vertebrate fossils, pollen, and spores indicate a warm, humid climate during the late middle Pleistocene. High uranium concentrations in the mammalian teeth indicate exposure to saline water, suggesting highly evaporative conditions in the past. Late Pleistocene sediment dated between 24.28+/-0.39cal ky BP and 13.15+/-340ky BP has yielded pollen and spores indicating cool, dry climatic conditions corresponding to Oxygen Isotope Stage 2 (OIS 2). An early Holocene palynological assemblage from the type locality at Baneta shows evidence for relatively dry conditions and a deciduous forest within the region. The Dhansi Formation provisionally replaces the Pilikarar Formation as the oldest Quaternary formation within the central Narmada Basin. The Baneta Formation, previously dated at 70ka to 128ka, correlates with the late Pleistocene and early Holocene. Our results highlight the need for further Quaternary geological and paleoanthropological research within the Narmada Basin, especially because dam construction threatens these deposits.

In the Tien Shan Mt., northeastern Uzbekistan, the Obi-Rakhmat rockshelter has yielded newly discovered hominid remains associated with an abundant Paleolithic industry and a rich faunal assemblage in typical cave fill sediment. Eight bovid teeth were dated by standard and isochron ESR to resolve the 50 ky discrepancy between the 14 C and 234 Th/ 234 U ages for Obi-Rakhmat. All the dentine contained high U concentrations, up to 150 ppm. External dose rates of 470– 820 μ Gy / y were calculated from volumetrically averaged sediment geochemistry for all layers and mineralogies within 30 cm of the teeth. One tooth from Layer 12.3 averaged 57 ± 2 ka assuming linear U uptake, while three from Layer 13 averaged 66 ± 2 ka , that from Layer 14.3 , 73 ± 4 ka , and three from Layer 21.2 , 87 ± 4 ka . Isochron and 230 Th/ 234 U analyses suggest that the teeth did experience linear uptake with ∼ 5 % recent secondary U remobilization. These dates indicate that the site was inhabitted during Oxygen Isotope Stages (OIS) 5a-4, as climates were generally cooling, but beginning to fluctuate more widely. Assuming a constant sedimentation rate of 22 cm/ky, the hominid remains date to ∼ 74 ka .

Although coupled 230Th/234U–ESR analyses have become routine for dating teeth, they have never been used for corals. While the ESR age depends on, and requires assumptions about, the time-averaged cosmic dose rate, D ¯ cos ( t ) , 230Th/234U dates do not. Since D ¯ cos ( t ) received by corals depends on the attenuation by any intervening material, D ¯ cos ( t ) response reflects changing water depths and sediment cover. By coupling the two methods, one can determine the age and a unique D ¯ cos , coupled ( t ) simultaneously. From a coral's water depth and sedimentary history as predicted by a given sealevel curve, one can predict D ¯ cos , sealevel ( t ) . If D ¯ cos , coupled ( t ) agrees well with D ¯ cos , sealevel ( t ) , this provides independent validation for the curve used to build D ¯ cos , sealevel ( t ) . For six corals dated at 7–128 ka from Florida Platform reef crests, the sealevel curve by Waelbroeck et al. [2002. Sea-level and deep water temperature changes derived from benthonic foraminifera isotopic records. Quat. Sci. Rev. 21, 295–305] predicted their D ¯ cos , coupled ( t ) values as well as, or better than, the SPECMAP sealevel curve. Where a whole reef can be sampled over a transect, a precise test for sealevel curves could be developed.

In 2012, bones and tusks of mammoths and remains of other large mammals scattered in a line 130 m long have been discovered in the loess deposits at the Nosak mound in the Kostolac Basin (Northeastern Serbia). Preliminary analyses indicate that remains come from Mammuthus trogontherii , Equus ferus mosbachensis and Cervidae indet. Steppe mammoth remains originate from at least four individuals, three adults, and one juvenile. They include the largest steppe mammoth tusks ever reported. The mammalian remains were mostly found disarticulated, except for few articulated skeleton elements. Individual bones and teeth were encased within thick carbonate concretions. From their composition, morphology, and manner of formation, these carbonate concretions resemble the characteristic “loess dolls” that form in loess. Bones were exposed to subaerial weathering for some time before burial. Some damage on the bones indicates biogenic agents of their fragmentation and dispersal. Animals were probably attracted to the spot by a water source in the vicinity, such as a spring or intermittent stream. The bones and teeth accumulated at a single level within the loess likely deposited in MIS 6, just above the upper of two paleosols formed during MIS 7. A sample from a mammoth molar plate has been ESR dated at 192 ± 5 ka, correlating with the very early MIS 6, near the MIS 6/7 boundary. This makes the Nosak mammoth the most recent occurrence of steppe mammoths in Europe, and the sole find dated to MIS 6.

Resume De nouvelles analyses sedimentologiques et chronologiques furent integrees afin de determiner les taux de sedimentation, l'humidite relative et les paleotemperatures dans les depots du Dernier Glaciaire (Wurmien) a Divje babe I, actuellement le site paleolithique le plus intensivement etudie en Slovenie. Des estimations de paleotemperatures et de paleoprecipitations locales furent verifiees par comparaison aux donnees paleontologiques et paleobotaniques, puis aux donnees globales de la palynologie et du δ18O. Onze couches archeologiques furent datees par 42 datations ESR independantes sur 26 dents d'ours des cavernes. De nombreux indices sedimentaires indiquent qu'il y a eu de fortes fluctuations climatiques a Divje babe lors du Pleistocene recent. Les datations ESR et les donnees sedimentologiques et biostratigraphiques des couches 2 a 23 suggerent que la sequence stratigraphique appartient principalement aux stades isotopiques 5 et 3, et en partie au stade 4. Un marqueur chronostratigraphique valide est correle avec la limite entre les stades 5 et 4. La flute, datee de l'interstade Moerschoofd-Glinde ou Oerel, est certainement plus ancienne que 46 ka. Elle fut analysee par tomographie informatisee a multisections (MSCT) et reinterpretee selon deux hypotheses : l'une propose une origine artificielle des trous, l'autre une origine naturelle. Il y a quatre trous sur la diaphyse ; au moins deux furent realises anterieurement aux alterations (grignotages) sur les extremites de la diaphyse, et des carnivores n'ont pas pu faire tous les trous, mais au maximum un. Les trous sont tres probablement artificiels, realises par combinaisons d'outils simples en os et en pierre. La majorite, et sans doute l'ensemble, des alterations causees par les carnivores sont d'origine secondaire. Des conclusions concernant l'origine des trous ne peuvent pas etre fondees sur la seule base de ces alterations, et l'hypothese de leur origine artificielle ne peut etre exclue.

On October 15, 2002, just before the national Geological Society of America GSA meetings that he rarely missed, Glenn A. Goodfriend passed away prematurely at age 51. Following a serious illness that began early in 2002, he died at George Washington University Hospital from pneumonia and other complications due to rhinocerebral mucomycosis, a systemic fungal infection. Glenn is survived by his father and stepmother, Morton and Theresa Goodfriend. A multidisciplinary scientist, Glenn studied evolutionary land snail ecology, amino acid racemization biogeochemistry, and geochronology, and applied these to problems in Quaternary stratigraphy, paleontology, zoology, geoarchaeology, paleoclimatology, and the marine sciences. A native of New Rochelle, NY, Glenn graduated with a Ph.D. in Zoology from the University of Florida in 1983. From 1983 to 1992, he worked as a PDF, research scientist, and finally senior scientist at the Weizmann Institute in Israel. From 1990 to 1998, he was a Senior Research Associate in the Geophysical Laboratory at the Carnegie Institution of Washington. From 1993 to 1995, he served as an adjunct faculty member at Johns Hopkins University. From 1998 until his death, Glenn was a Research Professor at the Earth and Environmental Sciences Department at George Washington University. Glenn published more than 70 scientific papers, many of them seminal classics, not counting the many left unfinished on his computer. As a broad scientific thinker, he collaborated on projects ranging from taphonomy to 14 C calibration. After organizing the 1998 international AAR conference, Glenn served as the lead editor on Perspectives in Amino Acid and Protein Geochemistry (Goodfriend et al., 2000). In 2002, he held almost 400 k$ in NSF grants. We will remember Glenn for his amazing ability to help others and his phenomenal attention to scientific detail. He allowed colleagues and students alike to pick his brain about lab procedures and research ideas, and he would take time from his busy schedule to troubleshoot experiments. He was indefatigable in the field and laboratory. Glenn loved good food and chocolate, as well as tasting and collecting fine wines. His cellar had several hundred bottles, from which he often treated friends to an exceptional bouquet. His many colleagues will sorely miss his scientific creativity and contributions. Like a fine wine, he was gone too soon.

Electron spin resonance (ESR) dating of the hydroxyapatite (HAP) in tooth enamel uses an ESR signal that remains stable for approximately 10 19 years at 25 °C, and is particularly useful in the time range between the maximum 14 C and the minimum 39 Ar/ 40 Ar age limits. Because the ESR dating signal results from radiation damage to samples during burial, the ESR age depends on the radioisotope concentrations, within both the sample and its surrounding sediment. Since teeth are not closed systems with respect to U uptake, however, ESR dates must measure an U uptake model by coupled 230 Th/ 234 U-ESR dating, or assume one based on paleoclimatic and geological factors. Experiments to find criteria that might be used to determine the model in teeth too old for 230 Th/ 234 U dating began using samples whose abnormal HAP ESR spectra in the X-band hinted that fossil diagenesis might be the culprit. Unlike X-band, Q-band ESR spectroscopy resolves spectral peaks better, by separating signals with very similar g values for individual study. When examining abnormal enamel spectra from well fossilized Early Pleistocene and Pliocene teeth in the Q-band, the problematic signal can be resolved as two signals, both with g ∼2.002, but one considerably broader than the other. How much broader, however, appears to be a function of age. ESR theory suggests that the broader signal results from crystal distortion, as might be expected in fossilized samples. To test this, modern tooth enamel was artificially fossilized by prolonged heating in a buffered aqueous solution. To test if the teeth had developed characteristics typical in naturally fossilized teeth, the samples were analyzed by HPLC and GC to determine their amino acid racemization (AAR) ratios. Although the Q-band spectra from artificially fossilized teeth did not entirely mimic those from natural fossilization, similar ESR signal broadening occurred and correlated with the aIle/Ile ratios from the AAR analyses. Therefore, fossil diagenesis appears to cause distorted HAP crystals, which would make teeth more likely to absorb U through microcracks in the enamel. This suggests that samples exhibiting a broad peak might have absorbed much of their U relatively recently, and that accurate ESR dating requires a recent uptake model.

Mezmaiskaya Cave has yielded more than 10,000 artifacts, thousands of very well preserved faunal remains, and hominin remains, found in seven Middle Paleolithic (Mousterian) and three Upper Paleolithic levels. A complete Neanderthal infant skeleton was preserved in anatomical juxtaposition lying on a large limestone block, overlain by the earliest Mousterian layer, Layer 3. Twenty-four skull fragments from a 1-2 year-old Neanderthal infant, showing post-mortem deformation, occurred in a pit originating in the Mousterian Layer 2 and penetrating into underlying layers 2A and 2B(1). Bone from Layer 2A was dated by AMS 14C at 35.8-36.3+/-0.5 kyr BP. Direct dating of Neanderthal bone from Layer 3 gave an age of 29 kyr, but that is now considered to be due to contamination by modern carbon. Fourteen large mammal teeth from Layers 2 through 3 have been dated by standard electron spin resonance (ESR). Low U concentrations in both the enamel and dentine ensure that ESR ages do not depend significantly on the U uptake model, but do depend strongly on the sedimentary dose rates. Assuming a sedimentary water concentration equal to 20 wt%, ESR ages for the Mousterian layers range from 36.2 to 73.0+/-5.0 ka.

The lower beds at Olduvai Gorge are well known for containing early hominid fossils and Oldowan stone tools, and their ages have been established by 40Ar/39Ar dating and paleomagnetic stratigraphy. Ages are generally less certain for the upper deposits at Olduvai Gorge because of the scarcity of datable tuffs. The youngest archaeologically significant site at Olduvai is microlithic LSA, which lies in the type section of the Naisiusiu Beds. The age for the site is controversial, with 14C dates of 17,000–17,550 (Hay, R.L., 1976 Geology of Olduvai Gorge, University of California Press, Berkeley) and >42,000 BP (Manega, P.C., 1993. Geochronology, geochemistry, and isotopic study of the Plio–Pleistocene Hominid sites and the Ngorongoro Volcanic Highland in Northern Tanzania. Unpublished Ph.D. Thesis, University of Colorado, Boulder, CO). The tuff bed in the zone with artifacts does not contain materials datable by 40Ar/39Ar, and some other dating method was needed. In the summer of 2001, five equid teeth were collected from the type Naisiusiu site. Another tooth had previously been collected. ESR ages have been determined for three teeth from the archaeological level and their ages cluster around 62±5 ka, assuming linear uranium uptake. Another tooth from a level without artifacts and believed to be significantly younger dated to 39±5 ka, again assuming LU. These dates are considerably older than previous estimates and suggest that the East African MSA/LSA transition occurred very early.

Near Hatay, the Antakya-Samandag-Cyprus Fault (ASCF), East Anatolian and Dead Sea Fault Zones, the large faults that form the edges of the African, Anatolian, Cyprus and Arabian Plates, all produce large earthquakes, which have decimated Hatay repeatedly. Near Samandag, Hatay, differential vertical displacement on the ASCF has uplifted the southeastern side relative to northwestern side, producing large fault scarps that parallel the Asi (Orontes) River. Tectonic uplift coupled with Quaternary sealevel fluctuations has produced several stacked marine terraces stranded above current sealevel. This study dated 24 mollusc samples from 10 outcrops on six marine terraces near Samandag electron spin resonance (ESR). Ages were calculated using time-averaged and volumetrically averaged external dose rates, modelled by assuming typical water depths for the individual species and sediment thicknesses estimated from geological criteria. Uplift rates were then calculated for each fault block. At all the Magaracik terraces, the dates suggest that many shells were likely reworked. On the 30 m terrace at Magaracik IV (UTM 766588-3999880), Lithophagus burrows with in situ shells cross the unconformity. One such shell dated to 62 ± 6 ka, setting the minimum possible age for the terrace. For all the Magaracik terraces at ∼30 m above mean sealevel (amsl), the youngest ages for the reworked shells, which averaged 60 ± 3 ka for six separate analyses, sets the maximum possible age for this unit. Thus, the terrace must date to 60-62 ± 3 ka, at the MIS 3/4 boundary when temperatures and sealevels were fluctuating rapidly. Older units dating to MIS 7, 6, and 5 likely were being eroded to supply some fossils found in this terrace. At Magaracik Dump (UTM 765391-4001048), ∼103 m amsl, Ostrea and other shells were found cemented in growth position to the limestone boulders outcropping there

Tooth enamel is one of the most promising materials for electron spin resonance (ESR) dating because the X-band signal is large, easy to measure, and extremely stable. The mean lifetime at ambient temperature has been measured greater than the age of the Earth! However, the X-band spectrum in fossil teeth is, in fact, a composite of two signals that can be resolved if the sample is examined in the Q-band region. The relative size of the two signals appears to be a function of degree of fossilization; older teeth have a better-defined second signal. A study of the dependence of these signals on radiation dose, microwave power, and temperature strongly suggests that both signals are located in the hydroxyapatite crystal structures. As such, then, the X-band spectrum, measured at moderate modulation amplitude, is suitable for determining the age of fossil teeth.

In electron spin resonance (ESR) dating tooth enamel, after selecting the appropriate U uptake model, the most significant uncertainty lies in the external dose rate, Dext(t), which can vary with time. Unlike standard ESR which measures the external dose rate in the modern context, Dext(t0), assuming that it reflects the actual external dose rate over the millennia, the isochron method calculates the time-averaged dose rate, D ext (t) , experienced by the tooth without such assumptions. In 45 teeth ranging from 30 ka to 4.5 Ma from 17 sites, D ext (t) determined by EU or LU isochrons only equalled Dext(t0) about 50% of the time. In several sites, geologic evidence indicates that secondary sedimentary processes have significantly altered sedimentary compositions and/or water concentrations, and hence, Dext(t), over time, accounting for 60-80% of D ext (t)–D ext (t 0 ) disagreements. Simulated isochrons suggest that at least seven teeth, whose isochrons had negative ages or D ext (t) , probably had lost U, while five, with accurate ages but very large D ext (t) , have likely experienced a second U uptake event.

At Bau de l'Aubesier, Provence, Mousterian artifacts and human teeth occur in inhomogeneous (“lumpy”) sedimentary deposits that include bone and tooth fragments and extensive burnt horizons. Electron spin resonance (ESR) isochron analyses of mammal teeth, which use multiple subsamples with different U concentrations, can measure the external dose rate experienced by the tooth regardless of reworking and sedimentary dose rate changes. Isochron analyses do depend on the U uptake model assumed, but can also identify teeth that have experienced secondary U uptake or leaching. Using 11 teeth from six archaeological layers, the isochrons demonstrate that at least three teeth have experienced secondary uptake. For eight teeth, the U uptake has apparently not followed strictly early (EU), linear (LU), or recent uptake (RU), but more closely approximates LU-RU. Comparing volumetrically averaged sedimentary geochemistry with thermoluminescent dosimetry suggests that fossil tissues in the sediment have also experienced LU-RU uptake. LU-RU uptake can explain standard ESR ages that underestimate the true fossil age. © 2001 John Wiley & Sons, Inc.

At many archaeological sites, including Bau de l'Aubesier, La Quina, and La Chaise-de-Vouthon, artefacts, teeth, and bones occur in heterogeneous (“lumpy”) sedimentary deposits that include bone and tooth fragments. Due to uranium (U) uptake by the bones and teeth in the adjacent sediment, the external dose rate experienced by teeth, bones, or the sediment itself will have changed over time. Such changes must be considered when calculating dose-dependent ages, whether thermoluminescent (TL) age for burnt flint artefacts, optically stimulated luminescent (OSL) or radioluminescent (RL) ages for sediment, or electron spin resonance (ESR) ages for the teeth therein. U uptake (or loss) in the sedimentary bone and tooth fragments can be modelled in the same manner as U uptake (or loss) in the dated teeth. Compared to dose rates derived from single bulk sedimentary geochemical analyses, volumetrically averaged sedimentary dose rates at Bau de l'Aubesier show significant differences depending on the model adopted for the U uptake in order to calculate the dosimetric contribution from the sedimentary components that had absorbed U.

At Bau de l’Aubesier, Provence, France, Mousterian artefacts and human teeth occur in inhomogeneous (“lumpy”) sedimentary deposits that include bone and tooth fragments. Due to uranium (U) uptake by the bones and teeth, the external dose rate experienced by the teeth has changed over time. Such changes must be considered when calculating thermoluminescence (TL) ages for burnt flint artefacts or electron spin resonance (ESR) ages for the teeth therein. Here, we assess the external dose rates using three methods: in situ TL dosimetry gives the modern dose rate, whereas volumetrically averaged geochemical analysis is used to estimate time-averaged dose rates that consider U uptake by U-rich sedimentary components (Blackwell and Blickstein, 2000. Quarternary International 68–71, 329–343). In ESR isochron analysis (Blackwell and Schwarcz, 1993. Applied Radiation and Isotopes 44, 243–252), multiple subsamples with variable U concentrations measure the external dose rate experienced by the tooth regardless of reworking, but do depend on the uptake model assumed. The methods each suggest significantly different dose rates. TL dosimetry for two combustion horizons measured external γ dose rates at 0.143±0.012 mGray/y in Layer IV and 0.184±0.016 mGray/y in Layer H. Geochemical analysis when volumetrically averaged to account for the influence from different sedimentary components indicates external γ dose rates ranging from as low as 0.094±0.024 mGray/y assuming RU for U-rich sedimentary components to a maximum of 0.251±0.048 mGray/y assuming EU for the U-rich components. Isochron analyses suggest more variable dose rates, ranging from a minimum of 0.009±0.040 mGray/y (LU) in the lower layers to a high of 1.103±0.160 mGray/y (EU) in Layer H1. Three isochrons indicated that the teeth had experienced U leaching or a second uptake event which would affect the accuracy of the dose rate determinations for those teeth. Other teeth may have experienced similar processes. Quaternary researchers who want reliable dates in the age ranges for ESR or TL must carefully consider both the nature of the sediment, especially U-rich bone fragments, and its geometric arrangement around the samples to be dated. Corresponding results using more than one analytic method may be required for a reasonable confidence level.

ESR dating requires that growth curves be determined by interpreting complex spectra. Spectra, however, can vary significantly in shape and field position between different samples, or occasionally between subsamples, even though the mineralogy remains the same. In some cases, this spectral variability does not affect the resulting accumulated dose calculation. In other cases, signal subtraction may be needed. However, some samples that until recently might have been considered unsuitable for dating are now shown to yield accurate and precise results because a broad interference peak is integral to the hydroxyapatite signal. By studying the spectrum at the Q-band frequency, it can be shown that the interfering signal in most cases is not a problem for dating. A second concern has been that artificially irradiating sample aliquots can introduce a short-lived component that is simply an unstable enhancement of the dating signal. The apparent accumulated dose from growth curves created immediately after irradiation is considerably greater than that after annealing, although the curve's shape remains unchanged. Annealing both the natural and artificially irradiated signal shows the dating signal's lifetime to be greater than 10 10 years.

A single radiation-sensitive ESR signal at g = 2.0018 occurs in well crystallized fossil tooth enamel, but not in modern teeth. In dating fossil teeth, the equivalent radiation dose (AΣ needed to produce the observed ESR signal is the integral, with respect to time, of the natural, environmental dose rate experienced by the tooth after its deposition. Regardless of the uranium (U) uptake history assumed, a reliable age estimate requires a good estimate for the external dose rate during the tooth's history. If teeth in a stratigraphic unit have been reworked from older units or are post-depositional intrusions, external dose rates measured in situ do not accurately reflect those experienced by the tooth. For teeth from a single unit, significant variations in the calculated ages, AΣs, enamel or dentine U concentrations all indicate mixed sample collections. Where enough subsamples can be collected from single teeth, isochron analyses negate the need for a separate external dose measurement, while calculating the sample age and the external dose rate experienced by the tooth. Failing that, modelling the sedimentary dose rates using time-averaged total external dose calculations becomes necessary. These principles are illustrated using teeth from the australopithecine sites Sterkfontein and Swartkrans, South Africa.

The radiation sensitive ESR signal at g = 2.0018 in fossil enamel can be used to date teeth absolutely, providing a suitable U uptake model can be selected, and the external dose rate, Dext can be accurately calculated. Apart from the uptake model, the most obvious uncertainty lies in Dext. With the isochron method, Dext can be derived easily during the ESR analysis. By plotting the AD vs. the total internal dose rate for teeth where multiple subsamples have been analyzed, a regression line, the isochron, can be determined for each model age calculation. Each isochron slope represents the sample age, while its y-intercept gives the total external dose, Aext. In the preliminary test, the isochron method was used to date two teeth from Bau de l'Aubesier, Provence. Both isochron calculations produced a good estimate for the total external dose, Aext. Although the external dose rate, Dext, so derived is now uptake-model dependent, this method should revolutionize ESR dating.

Barnacles have never been successfully dated by electron spin resonance (ESR). Living mainly in the intertidal zone, barnacles die when sea level changes cause their permanent exposure. Thus, dating the barnacles dates past sea level changes. From this, we can measure apparent sea level changes that occur due to ocean volume changes, crustal isostasy, and tectonics. ESR can date aragonitic mollusc shells ranging in age from 5 ka to at least 500 ka. By modifying the standard ESR method for molluscs to chemically dissolve 20 microm from off the shells, six barnacle samples from Norridgewock, Maine, and Khyex River, British Columbia, were tested for suitability for ESR dating. Due to Mn2+ interference peaks, the four Maine barnacle samples were not datable by ESR. Two barnacles from BC, which lacked Mn2+ interference, yielded a mean ESR age of 15.1 +/- 1.0 ka. These ages agree well with 14C dates on the barnacles themselves and wood in the overlying glaciomarine sediment. Although stability tests to calculate the mean dating signal lifetime and more ESR calibration tests against other barnacles of known age are needed to ensure the method's accuracy, ESR can indeed date Balanus, and thus, sea level changes.

One way to assess a new dating method's reliability is by comparing its results with those from well established, independent techniques. A controlled test of the electron spin resonance (ESR) dating method as it is currently being applied to teeth was attempted for the time range 100–250 ka, beyond that of 14 C, at the archaeological site of La Chaise-de-Vouthon (Charente, France). Although absent in modern enamel, a single ESR signal with g = 2.0018 in fossil tooth enamel hydroxyapatite increases in amplitude with increasing irradiation doses. ESR ages are derived from the ratio of the AD, the radiation dose needed to produce the observed ESR signal, relative to the natural, environmental dose rate (ED) experienced by the tooth after deposition. Since the age depends on the uranium (U) uptake history assumed, three ages are calculated assuming: (1) early U uptake (EU); (2) continuous (linear) uptake (LU); (3) recent uptake (RU). Generally, the LU age agrees best with known ages determined by other methods, although the RU model is better for some teeth. ESR dating assumes that the fossil has not suffered recrystallization or significant diagenetic alteration. In the preliminary test, three teeth were dated. In Bourgeois-Delaunay, a bovid molar associated with Palaeolithic artefacts was collected from layers dated at 101 ± 12 to 114 ± 7 ka by 230 Th 234 U dating of the over- and underlying stalagmitic floors. From Suard, two Equus teeth were collected from beneath a stalagmitic floor dating 112 ± 12 ka. ESR dating teeth significantly underestimated the true age for the teeth: the mean ESR ages range from 37 to 94 ka with standard errors of 2–6 ka, and good replicability. Although more teeth at La Chaise need to be tested to ascertain that the underestimation does not result from random variation commonly seen among teeth within one unit, the consistent underestimation suggests a fault in one of the assumptions underlying the dating method. The most obvious source of error lies in the difficulty in modelling the external γ dose. Only U leaching, not incorrectly modelled U uptake, would cause the underestimation. Diagenetic alteration may also cause anomalous fading, thermal instability, variation in k , or ESR signal suppression. More study into the effects of diagenesis alteration on enamel ESR signals is needed, as is a reevaluation of the mean signal life and α efficiency for several more enamel samples.

In any fossil site, dating the site is essential to understanding the site’s significance, because chronological data permits comparisons with materials from other sites, and ultimately enables regional settlement patterns, migration, or evolutionary rates to be determined. A dating method’s ability to date significant fossil materials directly rather than just dating associated sedimentary or rock units adds to its archaeological and paleontological utility. Electron spin resonance (ESR) dating can provide chronometric ages for vertebrate teeth throughout the Pleistocene and late Pliocene. For mollusc shells and coral, ESR’s effective dating range spans much of the Pleistocene.