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1.
Proc Natl Acad Sci U S A ; 117(52): 32982-32988, 2020 12 29.
Artículo en Inglés | MEDLINE | ID: mdl-33318206

RESUMEN

The Aral Sea basin in Central Asia and its major rivers, the Amu Darya and Syr Darya, were the center of advanced river civilizations, and a principal hub of the Silk Roads over a period of more than 2,000 y. The region's decline has been traditionally attributed to the devastating Mongol invasion of the early-13th century CE. However, the role of changing hydroclimatic conditions on the development of these culturally influential potamic societies has not been the subject of modern geoarchaeological investigations. In this paper we report the findings of an interdisciplinary investigation of archaeological sites and associated irrigation canals of the Otrar oasis, a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage site located at the confluence of the Syr Darya and Arys rivers in southern Kazakhstan. This includes radiometric dating of irrigation canal abandonment and an investigation of Arys river channel dynamics. Major phases of fluvial aggradation, between the seventh and early ninth century CE and between 1350 and 1550 CE coincide with economic flourishing of the oasis, facilitated by wet climatic conditions and higher river flows that favored floodwater farming. Periods of abandonment of the irrigation network and cultural decline primarily correlate with fluvial entrenchment during periods of drought, instead of being related to destructive invasions. Therefore, it seems the great rivers of Central Asia were not just static "stage sets" for some of the turning points of world history, but in many instances, inadvertently or directly shaped the final outcomes and legacies of imperial ambitions in the region.

2.
J Hum Evol ; 135: 102646, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31450172

RESUMEN

The Initial Upper Paleolithic (IUP) temporally overlaps with the range expansion of Homo sapiens populations in various parts of Eurasia and is often considered a key archaeological phase for investigating behavioral changes from the Middle Paleolithic. This paper reports upon new data from IUP occupations at Wadi Aghar, a rock shelter site in the southern Levant. In combining the results of radiometric dates and lithic analyses, we clarify the chronological and cultural position of Wadi Aghar assemblages in the Levantine IUP. As for the records about mobility, on-site activities, and resource procurement behaviors, we present analyses of lithic use-wear, tool-type composition, soil micromorphology, and marine shells. The lithic analyses and the optically stimulated luminescence (and subsidiary radiocarbon) dating of the Wadi Aghar materials suggest their chronocultural position in the IUP (45-40 ka for Layers C-D1; 39-36 ka for Layer B; possibly 50 ka for Layer D2), providing the southernmost location for the IUP in Eurasia. In the Levant, Wadi Aghar represents one of the few IUP sites in the inland areas. The results also indicate that the timing and technological sequences from the IUP to the following bladelet industries differed between the inland and coastal zones, likely reflecting geographically variable adaptive behaviors and/or cultural transmissions. One of the behavioral characteristics of IUP foragers at Wadi Aghar is the procurement of remote resources, represented by the transportation of marine shells from the Red Sea: Canarium fusiforme and Canarium cf. mutabile. Whether it was a direct procurement with increased mobility or a result of intergroup exchanges, it was not part of behavioral repertoires during the late MP in the same area. This can be understood as the expansion of resource procurement range, functioning as additional buffers from risk in the semiarid environments in the inland Levant.


Asunto(s)
Fósiles , Tecnología , Exoesqueleto , Animales , Arqueología , Humanos , Jordania
3.
Proc Natl Acad Sci U S A ; 111(16): 5848-53, 2014 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-24711426

RESUMEN

Mammalian extinction worldwide during the Late Pleistocene has been a major focus for Quaternary biochronology and paleoecology. These extinctions have been variably attributed to the impacts of climate change and human interference. However, until relatively recently, research has been largely restricted to the Americas, Europe, and Australasia. We present the oldest Middle-Late Pleistocene stratified and numerically dated faunal succession for the Indian subcontinent from the Billasurgam cave complex. Our data demonstrate continuity of 20 of 21 identified mammalian taxa from at least 100,000 y ago to the present, and in some cases up to 200,000 y ago. Comparison of this fossil record to contemporary faunal ranges indicates some geographical redistribution of mammalian taxa within India. We suggest that, although local extirpations occurred, the majority of taxa survived or adapted to substantial ecological pressures in fragmented habitats. Comparison of the Indian record with faunal records from Southeast and Southwest Asia demonstrates the importance of interconnected mosaic habitats to long-term faunal persistence across the Asian tropics. The data presented here have implications for mammalian conservation in India today, where increasing ecological circumscription may leave certain taxa increasingly endangered in the most densely populated region of the world.


Asunto(s)
Mamíferos/fisiología , Animales , Geografía , Sedimentos Geológicos/química , Humanos , India , Luminiscencia , Paleontología
4.
J Hum Evol ; 66: 1-17, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24210611

RESUMEN

We report the discovery of a new type of hominin site in the Levant, inhabited during MIS 6-5. The site, found within a karst depression at Nesher Ramla, Israel, provides novel evidence for Middle Paleolithic lifeways in an environmental and depositional setting that is previously undocumented in the southern Levant. The carbonate bedrock in the area is characterized by surface depressions formed by gravitational sagging of the rock into underlying karst voids. In one such depression, an 8 m thick sequence comprising rich and well-preserved lithic and faunal assemblages, combustion features, hundreds of manuports and ochre was discovered. Here we focus on the geological and environmental setting and present optically stimulated luminescence (OSL) ages for the 8 m sequence, aiming to place the site within a firm chronological framework and determine its significance for a more complete reconstruction of cultural developments in the Levantine Middle Paleolithic. To that end, preliminary results of the lithic and faunal studies are also presented.


Asunto(s)
Arqueología , Cultura , Fósiles , Hombre de Neandertal/fisiología , Vertebrados/clasificación , Animales , Israel , Mediciones Luminiscentes
5.
J Hum Evol ; 77: 187-95, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25456825

RESUMEN

Excavation of Toca do Serrote das Moendas, in Piauí state, Brazil revealed a great quantity of fossil wild fauna associated with human remains. In particular, fossils of a cervid (Blastocerus dichotomus) were found, an animal frequently pictured in ancient rock wall paintings. In a well-defined stratum, two loose teeth of this species were found in close proximity to human bones. The teeth were independently dated by electron spin resonance (ESR) in two laboratories. The ages obtained for the teeth were 29 ± 3 ka (thousands of years) and 24 ± 1 ka. The concretion layer capping this stratum was dated by optically stimulated luminescence (OSL) of the quartz grains to 21 ± 3 ka. As these values were derived independently in three different laboratories, using different methods and equipment, these results are compelling evidence of early habitation in this area.


Asunto(s)
Cuevas , Fósiles , Datación Radiométrica/métodos , Diente/química , Brasil , Espectroscopía de Resonancia por Spin del Electrón , Humanos , Paleontología
6.
J Hum Evol ; 75: 16-27, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25016565

RESUMEN

The timing of the end of the Middle Palaeolithic and the disappearance of Neanderthals continue to be strongly debated. Current chronometric evidence from different European sites pushes the end of the Middle Palaeolithic throughout the continent back to around 42 thousand years ago (ka). This has called into question some of the dates from the Iberian Peninsula, previously considered as one of the last refuge zones of the Neanderthals. Evidence of Neanderthal occupation in Iberia after 42 ka is now very scarce and open to debate on chronological and technological grounds. Here we report thermoluminescence (TL) and optically stimulated luminescence (OSL) dates from El Salt, a Middle Palaeolithic site in Alicante, Spain, the archaeological sequence of which shows a transition from recurrent to sporadic human occupation culminating in the abandonment of the site. The new dates place this sequence within MIS 3, between ca. 60 and 45 ka. An abrupt sedimentary change towards the top of the sequence suggests a strong aridification episode coinciding with the last Neanderthal occupation of the site. These results are in agreement with current chronometric data from other sites in the Iberian Peninsula and point towards possible breakdown and disappearance of the Neanderthal local population around the time of the Heinrich 5 event. Iberian sites with recent dates (<40 ka) attributed to the Middle Palaeolithic should be revised in the light of these data.


Asunto(s)
Fósiles , Hombre de Neandertal/fisiología , Comportamiento del Uso de la Herramienta , Animales , Arqueología , Datación Radiométrica , España , Tecnología
7.
Data Brief ; 55: 110702, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39076830

RESUMEN

This dataset offers valuable insights into the luminescence saturation behaviour of 63-90 µm quartz grains sourced from the Carpathian Basin, as examined under controlled laboratory conditions. Its significance lies not only in shedding light on the luminescence properties specific to this region but also in facilitating comparative analyses with quartz samples from other geographic areas. Moreover, the dataset contributes novel findings to the ongoing investigations concerning the upper dating limit of quartz grains, which holds implications for refining luminescence dating methodologies. Grounded in the framework of several previous studies which underscore the challenges associated with utilizing quartz from certain regions for precise dose measurements, the dataset addresses the crucial aspect of setting upper dose limits for accurate luminescence dating. Consequently, the study conducts a series of tests to assess the proximity of natural sensitivity-corrected luminescence signals to laboratory saturation levels, particularly focusing on quartz samples from the Kisiljevo loess-palaeosol sequence. The dataset includes data from OSL saturation experiments conducted on sample 23019, along with associated calculations encompassing all 19 collected samples. This comprehensive dataset serves as a valuable resource for researchers and practitioners engaged in luminescence dating studies, offering detailed insights into saturation behaviours and dose-response characteristics of quartz grains from the Carpathian Basin. Beyond its immediate research implications, the dataset holds significant potential for reuse in various contexts. Researchers exploring luminescence properties of geological materials, particularly quartz grains, can leverage this dataset to compare saturation behaviours across different regions, thus enriching our understanding of luminescence dating methodologies on a broader scale. Additionally, the dataset could inform future studies on refining dose limits and calibration protocols, ultimately enhancing the accuracy and reliability of luminescence dating techniques. In summary, this dataset not only advances our understanding of luminescence saturation behaviours in quartz grains from the Carpathian Basin but also fosters collaborative research efforts aimed at refining luminescence dating methodologies and addressing broader questions in geochronology and palaeoenvironmental studies.

8.
Sci Total Environ ; 857(Pt 2): 159481, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36265626

RESUMEN

Through extensive field investigation in the Zoige Basin of the eastern Tibetan Plateau, a typical sedimentary profile was found on the front scarp of the second terrace of Maqu reach of the Yellow River at the outlet of the Zoige Basin. This profile contains the stratigraphic sequence of paleolake facies and paleo-riverbed floodplain facies. Field observation and the analysis of particle size characteristics and optically stimulated luminescence dating showed the following results: (1) The profile includes a pale blue-grey paleolake deposit, which formed in a deep-water anoxic environment. This deposit was overlain by a mottled pebble layer with pale yellow-orange lenticular sand, which represents typical paleo-riverbed floodplain deposits, indicating a strong hydrodynamic process. The typical unconformity contact relationship between the two deposits shows that the profile recorded the sedimentary information of the transformation of the Zoige paleolake environment into the Yellow River paleo-river environment, which provides powerful sedimentary evidence for the Yellow River dissecting the Zoige paleolake. (2) The optically stimulated luminescence dating results showed the Zoige paleolake was dissected by the Yellow River at 37 ka BP, resulting in the discharge of lake water. At 35 ka BP, the lake water gradually became shallow and disappeared, and the Yellow River subsequently connected the water system of the Zoige Basin. (3) The East Kunlun fault induced strong tectonic movement in the late Pleistocene, and the Tibetan Plateau had a warm and humid climate at 37 ka BP. Under these conditions, the headward erosion of the Yellow River was aggravated in the faulted wide valley grassland between the Anyemaqen mountains and Xiqing mountains, and the Zoige paleolake was dissected by the Yellow River from west to east in the Maqu bottleneck reach. The results of this study have important scientific significance for in-depth understanding of the evolution of river-lake water systems and the formation of the Yellow River source water system in the eastern Tibetan Plateau.


Asunto(s)
Lagos , Ríos , Humanos , Tibet , Facies , China , Agua
9.
J Quat Sci ; 37(2): 142-180, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35874300

RESUMEN

The article presents evidence about the Middle Palaeolithic and Middle to Upper Palaeolithic transition interval in the karst area of the Danube Gorges in the Lower Danube Basin. We review the extant data and present new evidence from two recently investigated sites found on the Serbian side of the Danube River - Tabula Traiana and Dubocka-Kozja caves. The two sites have yielded layers dating to both the Middle and Upper Palaeolithic and have been investigated by the application of modern standards of excavation and recovery along with a suite of state-of-the-art analytical procedures. The presentation focuses on micromorphological analyses of the caves' sediments, characterisation of cryptotephra, a suite of new radiometric dates (accelerator mass spectrometry and optically stimulated luminescence) as well as proteomics (zooarchaeology by mass spectrometry) and stable isotope data in discerning patterns of human occupation of these locales over the long term.

10.
J Quat Sci ; 36(4): 570-585, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34239219

RESUMEN

A detailed study is presented of a 15.3-m-thick Pleistocene coastal terrace located on the Cantabrian coast (northern Spain). Stratigraphic, sedimentological, topographic and micropalaeontological information is combined with a chronology based on luminescence dating to characterize the deposits. The sedimentary succession records: (i) a basal transgressive system, consisting of a wave-cut surface covered by a lower layer of beach gravels and upper beach pebbly sands; and (ii) a thicker upper highstand system (aggrading), comprising medium to very fine aeolian sands interbedded with thin palustrine muds. Luminescence dating involved a detailed sampling strategy (36 samples and two modern analogues) and the use of both quartz optically stimulated luminescence (OSL) and feldspar post-infrared infrared stimulated luminescence single aliquot regeneration protocols; feldspar results were used to confirm the completeness of bleaching of the quartz OSL signal. The quartz OSL luminescence age-depth relationship shows significant dispersion, but nevertheless two rapid phases of deposition can be clearly identified: one at ~130 ka [Marine Oxygen Isotope Stage (MIS) 5] and one at ~100 ka (MIS 5c). The top of the succession is dated to ~70 ka. The MIS 5e marine maximum flooding surface is identified at an elevation of 6.85 m above mean seal level. This elevation provides evidence of a regional sea-level highstand for this sector of the Cantabrian coast.

11.
Methods Protoc ; 3(1)2020 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-31947608

RESUMEN

Compared to quartz, the infrared stimulated luminescence (IRSL) of K-feldspar saturates at higher dose, which has great potential for extending the dating limit. However, dating applications with K-feldspar has been hampered due to anomalous fading of the IRSL signal. The post-IR IRSL (pIRIR) signal of K-feldspar stimulated at a higher temperature after a prior low-temperature IR stimulation has significantly lower fading rate. Different dating protocols have been proposed with the pIRIR signals and successful dating applications have been made. In this study, we review the development of various pIRIR dating protocols, and compare their performance in estimating the equivalent dose (De). Standard growth curves (SGCs) of the pIRIR signals of K-feldspar are introduced. Single-grain K-feldspar pIRIR dating is presented and the existing problems are discussed.

12.
Sci Total Environ ; 649: 264-283, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30173034

RESUMEN

Organic-poor, permeable quartz sands are often present at land-sea transition zones in coastal regions. Yet, the biogeochemical cycles of carbon, sulfur, and iron are not well studied here. The aim of this work was, therefore, to improve our understanding regarding the chemical processes in these prominent coastal sediments. A 10 m core was collected at a dune base of the barrier island Spiekeroog, Germany, for this purpose. Additionally, groundwater was sampled from a multi-level well for one year to record seasonal hydrochemical variations. Methods included the analyses of geochemical (total carbon, total inorganic carbon, reactive iron, total sulfur, reduced inorganic sulfur) and hydrochemical parameters (field parameters, major ions, DOC, and molecular compositions of DOM), as well as stable sulfur isotopes (δ34S-sulfate, -sulfide, -total reduced inorganic sulfur). Moreover, optically stimulated luminescence (OSL) dating was applied. Results show that the core sediments are very young (<500 a) and were rapidly deposited. They are characterized by remarkably low contents of organic carbon (<0.1% dw.), reactive iron (~10 mmol/kg), and iron sulfides (<3 mmol/kg). Groundwater salinities were low in the top core sediments and increased at depth during most times of the year. However, the sampling site is subject to (seasonally) varying salinities, which could be linked to the biogeochemical cycles. For instance, the infiltration of seawater-derived labile DOM during inundation events drives microbial respiration besides sedimentary organic matter. Oxygen and nitrate were the dominant electron acceptors for the decomposition of organic matter in near-surface groundwater, while sulfate reduction was constrained to the lower brackish sediments. Here, authigenic pyrite formation was inferred based on the detection of dissolved sulfide, intact pyrite framboids, and matching stable sulfur isotope signatures of dissolved and solid sulfides. We concluded that the extremely low organic carbon contents limit pyrite formation in the organic-poor, permeable quartz sands.

13.
Data Brief ; 25: 104267, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31388521

RESUMEN

This Data in Brief paper contains data (including images) from Quaternary sedimentary successions investigated along the Bol'shaya Balakhnya River and the Luktakh-Upper Taimyra-Logata river system on southern Taimyr Peninsula, NW Siberia (Russia). Marine foraminifera and mollusc fauna composition, extracted from sediment samples, is presented. The chronology (time of deposition) of the sediment successions is reconstructed from three dating methods; (i) radiocarbon dating of organic detritus (from lacustrine/fluvial sediment) and molluscs (marine sediment) as finite ages (usually <42 000 years) or as non-finite ages (>42 000-48 000 years) on samples/sediments beyond the radiocarbon dating limit; (ii) Electron Spin Resonance (ESR) dating on marine molluscs (up to ages >400 000 years); (iii) Optically Stimulated Luminescence (OSL) dating, usually effective up to 100-150 0000 years. Terrestrial Cosmogenic Nuclide (TCN) exposure dating has been applied to boulders resting on top of moraine ridges (Ice Marginal Zones). See (Möller et al., 2019) (doi.org/10.1016/j.earscirev.2019.04.004) for interpretation and discussion of all data.

14.
Methods Protoc ; 2(4)2019 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-31817635

RESUMEN

The impetus behind this study is to understand the sedimentological dynamics of very young fluvial systems in the Amazon River catchment and relate these to land use change and modern analogue studies of tidal rhythmites in the geologic record. Initial quartz optically stimulated luminescence (OSL) dating feasibility studies have concentrated on spit and bar deposits in the Rio Tapajós. Many of these features have an appearance of freshly deposited pristine sand, and these observations and information from anecdotal evidence and LandSat imagery suggest an apparent decadal stability. The characteristics of OSL from small (~5 cm) sub-samples from ~65 cm by ~2 cm diameter vertical cores are quite remarkable. Signals from medium-sized aliquots (5 mm diameter) exhibit very high specific luminescence sensitivity, have excellent dose recovery and recycling, essentially independent of preheat, and show minimal heat transfer even at the highest preheats. These characteristics enable measurement of very small signals with reasonable precision and, using modified single-aliquot regenerative-dose (SAR) approaches, equivalent doses as low as ~4 mGy can be obtained. Significant recuperation is observed for samples from two of the study sites and, in these instances, either the acceptance threshold was increased or growth curves were forced through the origin; recuperation is considered most likely to be a measurement artefact given the very small size of natural signals. Dose rates calculated from combined inductively coupled plasma mass spectrometry/inductively coupled plasma optical emission spectrometry (ICP-MS/ICP-OES) and high-resolution gamma spectrometry range from ~0.3 to 0.5 mGya-1, and OSL ages for features so far investigated range from 13 to 34 years to several 100 years. Sampled sands are rich in quartz and yields of 212-250 µm or 250-310 µm grains indicate high-resolution sampling at 1-2 cm intervals is possible. Despite the use of medium-sized aliquots to ensure the recovery of very dim natural OSL signals, these results demonstrate the potential of OSL for studying very young active fluvial processes in these settings.

15.
Mar Pollut Bull ; 131(Pt A): 530-546, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29886980

RESUMEN

Sediment runoff has been cited as a major contributor to the declining health of the Great Barrier Reef (GBR), however, climate and land use drivers have not been jointly evaluated. This study used alluvial archives from fluvial benches in two tributaries of the Upper Burdekin catchment together with the best available land use history and climate proxy records to provide insights into the timing of depositional events in this region over the past 500 years. This study suggests that mining and the increased runoff variability in the latter half of the nineteenth century are the likely sources of the original excess sediment that was used to build the bench features in these catchments. Grazing also contributed to increased bench sedimentation prior to 1900, however, the contribution of grazing was likely more significant in the second half of the 20th century, and continues to be a dominant land use contributor today.


Asunto(s)
Agricultura/historia , Ambiente , Sedimentos Geológicos/análisis , Minería/historia , Australia , Arrecifes de Coral , Sedimentos Geológicos/química , Historia del Siglo XIX , Historia del Siglo XX , Mediciones Luminiscentes , Tamaño de la Partícula , Clima Tropical
16.
Azania ; 48(4): 455-472, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25400300

RESUMEN

This paper proposes a new chronology for the burial complex at Jebel Moya, south-central Sudan. It reassesses the body of evidence from Sir Henry Wellcome's original 1911-1914 excavations in order to place the site within a firm chronological framework by: (a) applying an attribute-based approach to discern discrete pottery assemblages; and (b) applying initial OSL dates to facilitate the reliable dating of this site for the first time. Jebel Moya is re-interpreted as a burial complex situated on the southern periphery of the late Meroitic state, and its potential to serve as a chronological and cultural reference point for future studies in south-central and southern Sudan is outlined.


Cet article propose une nouvelle chronologie pour Jebel Moya, site funéraire du centre-sud du Soudan. Les données provenant des fouilles qui y furent menées par Sir Henry Wellcome en 1911­14 sont réexaminées afin de placer le site dans une trame chronologique ferme, en employant une analyse par attributs pour définir des assemblages distincts de céramique, et en mettant en œuvre des datation OSL pour faciliter la première datation fiable du site. Nous réinterprétons Jebel Moya comme un site funéraire à la périphérie sud de l'état Méroitique tardif, et nous soulignons le potentiel du site pour servir de référence chronologique et culturelle à de futures études dans le sud et le centre-sud du Soudan.

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