Radiometric Dating

放射性约会
  • 文章类型: Journal Article
    尽管非洲作物具有当代重要性,但其历史仍然知之甚少。整合来自西方的农作物,东部和北部非洲可能首先发生在东部非洲的大湖区;然而,人们对这些农业系统何时以及如何合并知之甚少。本文介绍了来自肯尼亚西部KakapelRockshelt的大约9000年考古序列的考古植物学分析,包含赤道东非内部最大,最广泛的古植物学记录。碳化种子上的直接放射性碳年代证明了西非作物cow豆的存在(Vignaunguiculata(L.)沃尔普)大约2300年前,与驯养牛(Bostaurus)的最早日期同步。豌豆(PisumsativumL.或PisumabhyssinicumA.Braun)和高粱(高粱双色(L.)Moench)来自东北和东部非洲手指小米(Eleusinecoracana(L.)Gaertn。)后来被合并,至少1000年前。结合来自Kakapel和周边地区的古老DNA证据,这些数据支持这样一种情景,即东非不同驯化物种的使用随着时间的推移而变化,而不是作为一个单一的包装到达和维持.调查结果强调了当地异质性在塑造撒哈拉以南非洲粮食生产传播方面的重要性。
    The histories of African crops remain poorly understood despite their contemporary importance. Integration of crops from western, eastern and northern Africa probably first occurred in the Great Lakes Region of eastern Africa; however, little is known about when and how these agricultural systems coalesced. This article presents archaeobotanical analyses from an approximately 9000-year archaeological sequence at Kakapel Rockshelter in western Kenya, comprising the largest and most extensively dated archaeobotanical record from the interior of equatorial eastern Africa. Direct radiocarbon dates on carbonized seeds document the presence of the West African crop cowpea (Vigna unguiculata (L.) Walp) approximately 2300 years ago, synchronic with the earliest date for domesticated cattle (Bos taurus). Peas (Pisum sativum L. or Pisum abyssinicum A. Braun) and sorghum (Sorghum bicolor (L.) Moench) from the northeast and eastern African finger millet (Eleusine coracana (L.) Gaertn.) are incorporated later, by at least 1000 years ago. Combined with ancient DNA evidence from Kakapel and the surrounding region, these data support a scenario in which the use of diverse domesticated species in eastern Africa changed over time rather than arriving and being maintained as a single package. Findings highlight the importance of local heterogeneity in shaping the spread of food production in sub-Saharan Africa.
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  • 文章类型: Journal Article
    东亚智人的出现是一个具有重要研究兴趣的话题。然而,保存完好的人类化石,该地区的可日期上下文极为罕见,由于地层和年代学问题,经常成为激烈辩论的主题。通天岩洞,在柳州市柳江区,中国南方是智人最重要的化石之一,尽管它的年龄一直在争论,计时日期从中更新世晚期到晚更新世早期。在这里,我们为柳江人类化石提供了新的年龄估计和修订的起源信息,它们是中国智人最完整的化石骨骼之一。人类化石和放射性碳的U系列测年和含化石沉积物上的光学刺激发光测年提供了约33,000至23,000年前(ka)的年龄。修订后的年龄估计与中国北方其他人类化石的日期一致,天元洞(~40.8-38.1ka)和周口店上洞(39.0-36.3ka),表明H.sapiens在东亚的地理上广泛存在于晚更新世,这对于更好地了解该地区的人类扩散和适应具有重要意义。
    The emergence of Homo sapiens in Eastern Asia is a topic of significant research interest. However, well-preserved human fossils in secure, dateable contexts in this region are extremely rare, and often the subject of intense debate owing to stratigraphic and geochronological problems. Tongtianyan cave, in Liujiang District of Liuzhou City, southern China is one of the most important fossils finds of H. sapiens, though its age has been debated, with chronometric dates ranging from the late Middle Pleistocene to the early Late Pleistocene. Here we provide new age estimates and revised provenience information for the Liujiang human fossils, which represent one of the most complete fossil skeletons of H. sapiens in China. U-series dating on the human fossils and radiocarbon and optically stimulated luminescence dating on the fossil-bearing sediments provided ages ranging from ~33,000 to 23,000 years ago (ka). The revised age estimates correspond with the dates of other human fossils in northern China, at Tianyuan Cave (~40.8-38.1 ka) and Zhoukoudian Upper Cave (39.0-36.3 ka), indicating the geographically widespread presence of H. sapiens across Eastern Asia in the Late Pleistocene, which is significant for better understanding human dispersals and adaptations in the region.
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  • 文章类型: Journal Article
    欧洲中旧石器时代的过渡与尼安德特人的区域消失和智人的传播有关。在欧洲东部出现智人之后,晚期尼安德特人在西欧持续了几千年。两组之间发生了局部杂交2,但并非在所有情况下3。考古证据还表明,在这种转变过程中存在几种技术复合物,使我们的理解和行为适应与特定人类群体的关联复杂化4。制造商未知的一种技术复合体是Lincombian-Ranisian-Jerzmanowician(LRJ),在欧洲西北部和中部5-8有所描述。在这里,我们提出了形态学和蛋白质组分类鉴定,在Ranis(德国)的Ilsenhöhle地点与LRJ组合直接相关的人类遗骸的线粒体DNA分析和直接放射性碳测年。这些人类遗骸是欧亚大陆最早的直接上古石器时代的智人遗骸之一。我们表明,与LRJ相关的早期智人早在欧洲西南部的尼安德特人灭绝之前就存在于欧洲中部和西北部。我们的结果加强了在此过渡时期欧洲存在的不同人群和技术复合体的拼凑概念。
    The Middle to Upper Palaeolithic transition in Europe is associated with the regional disappearance of Neanderthals and the spread of Homo sapiens. Late Neanderthals persisted in western Europe several millennia after the occurrence of H. sapiens in eastern Europe1. Local hybridization between the two groups occurred2, but not on all occasions3. Archaeological evidence also indicates the presence of several technocomplexes during this transition, complicating our understanding and the association of behavioural adaptations with specific hominin groups4. One such technocomplex for which the makers are unknown is the Lincombian-Ranisian-Jerzmanowician (LRJ), which has been described in northwestern and central Europe5-8. Here we present the morphological and proteomic taxonomic identification, mitochondrial DNA analysis and direct radiocarbon dating of human remains directly associated with an LRJ assemblage at the site Ilsenhöhle in Ranis (Germany). These human remains are among the earliest directly dated Upper Palaeolithic H. sapiens remains in Eurasia. We show that early H. sapiens associated with the LRJ were present in central and northwestern Europe long before the extinction of late Neanderthals in southwestern Europe. Our results strengthen the notion of a patchwork of distinct human populations and technocomplexes present in Europe during this transitional period.
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  • 文章类型: Journal Article
    有史以来最大的灵长类动物,也是东南亚最大的大型动物之一,Gigantopithecusblacki1在中国持续了大约200万年,直到中更新世后期灭绝t2-4。考虑到它是过去260万年来少数灭绝的亚洲类人猿之一,它的灭亡是神秘的,而其他人,包括猩猩,幸存下来,直到今天5。G.blacki消失的原因仍未解决,但可以揭示该地区灵长类动物的恢复能力和大型动物的命运6。在这里,我们应用了三个多学科分析——时机,过去的环境和行为-到中国南方的22个洞穴。我们使用了来自六种测年技术的157个辐射年龄来建立G.blacki灭亡的时间表。我们表明,从230万年前开始,环境是森林和草的马赛克,为繁荣的G.blacki种群提供理想的条件。然而,就在29.5万年前到21.5万年前的灭绝窗口之前和期间,由于季节性的增加,环境变异性增强了,这导致了植物群落的变化和开放森林环境的增加。尽管其近亲Pongoweidenreichi设法使其饮食偏好和行为适应这种变异性,G.blacki表现出慢性压力和人口减少的迹象。最终,它为适应而进行的斗争导致了居住在地球上的最伟大的灵长类动物的灭绝。
    The largest ever primate and one of the largest of the southeast Asian megafauna, Gigantopithecus blacki1, persisted in China from about 2.0 million years until the late middle Pleistocene when it became extinct2-4. Its demise is enigmatic considering that it was one of the few Asian great apes to go extinct in the last 2.6 million years, whereas others, including orangutan, survived until the present5. The cause of the disappearance of G. blacki remains unresolved but could shed light on primate resilience and the fate of megafauna in this region6. Here we applied three multidisciplinary analyses-timing, past environments and behaviour-to 22 caves in southern China. We used 157 radiometric ages from six dating techniques to establish a timeline for the demise of G. blacki. We show that from 2.3 million years ago the environment was a mosaic of forests and grasses, providing ideal conditions for thriving G. blacki populations. However, just before and during the extinction window between 295,000 and 215,000  years ago there was enhanced environmental variability from increased seasonality, which caused changes in plant communities and an increase in open forest environments. Although its close relative Pongo weidenreichi managed to adapt its dietary preferences and behaviour to this variability, G. blacki showed signs of chronic stress and dwindling populations. Ultimately its struggle to adapt led to the extinction of the greatest primate to ever inhabit the Earth.
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  • 文章类型: Journal Article
    湿地覆盖了世界的一小部分,但对全球碳(C)封存有不成比例的影响,二氧化碳和甲烷的排放,和水生C通量。然而,影响湿地碳库和通量的潜在生物地球化学过程是复杂而动态的,使湿地C的测量具有挑战性。经过几十年的研究,许多观测,实验性的,已经开发了分析方法来理解和量化湿地C的池和通量。采样方法的范围从短期到长期以及局部到景观空间尺度。这篇综述总结了量化湿地C池和通量的常用和前沿方法。我们首先定义每个主要的C池和通量,并提供其对湿地C动力学的重要性的基本原理。对于每种方法,我们阐明了测量湿地C的哪些成分及其时空代表性和制约因素。我们描述了每种方法的实际考虑,比如通常使用一种方法的地点和时间,谁可以进行测量(专业知识,培训要求),以及方法是如何进行的,包括对设备复杂性和成本的考虑。最后,我们回顾了关键的协变量和辅助测量,这些测量可以增强对结果的解释并促进模型开发。我们描述的测量土壤的协议,水,植被,和气体也与生态学等相关学科有关。提高研究数据收集和报告的质量和一致性将有助于减少全球不确定性,并制定管理战略,将湿地用作基于自然的气候解决方案。
    在线版本包含补充材料,可在10.1007/s13157-023-01722-2获得。
    Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions.
    UNASSIGNED: The online version contains supplementary material available at 10.1007/s13157-023-01722-2.
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  • 文章类型: Journal Article
    通过质谱(ZooMS)在欧洲和亚洲北部的更新世遗址上的应用,发现了重要的新人类化石,并扩大了已识别动物群的范围。然而,没有系统的,到目前为止,已经尝试在东亚旧石器时代遗址上大规模应用ZooMS。这里,我们分析了来自中国东北的金斯台洞和中国南方的玉弥洞洞的866个形态非诊断骨,从考古视野到150-10kaBP。来自两个部位的骨骼都显示出高度的胶原蛋白保存和潜在的时间相关的脱酰胺模式,尽管位于非常不同的环境环境中。在金斯泰,我们确认了31块驼骨,其中五个是放射性碳,可追溯到37-20kaBP。所有过时的标本都对应于海洋同位素第3阶段和第2阶段的较冷时期。我们认为,金斯泰有骆驼,证明野生骆驼是大型动物类群的目标,很可能是早期现代人,在整个东北亚扩张期间。ZooMS在中国的大规模应用突显了该方法的潜力,可进一步加深我们对东亚古人类学和动物考古记录的了解。
    The application of Zooarchaeology by Mass Spectrometry (ZooMS) on Pleistocene sites in Europe and northern Asia has resulted in the discovery of important new hominin fossils and has expanded the range of identified fauna. However, no systematic, large-scale application of ZooMS on Palaeolithic sites in East Asia has been attempted thus far. Here, we analyse 866 morphologically non-diagnostic bones from Jinsitai Cave in northeast China and Yumidong Cave in South China, from archaeological horizons dating to 150-10 ka BP. Bones from both sites revealed a high degree of collagen preservation and potentially time-related deamidation patterns, despite being located in very distinct environmental settings. At Jinsitai, we identified 31 camel bones, five of which were radiocarbon dated to 37-20 ka BP. All dated specimens correspond to colder periods of Marine Isotope Stages 3 and 2. We regard the presence of camels at Jinsitai as evidence of wild camels being a megafauna taxon targeted, most likely by early modern humans, during their expansion across northeast Asia. This large-scale application of ZooMS in China highlights the potential of the method for furthering our knowledge of the palaeoanthropological and zooarchaeological records of East Asia.
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  • 文章类型: Journal Article
    川洞洞穴是重要的旧石器时代晚期遗址,因为它记录了中国南方骨骼工具的早期出现。我们使用单等分试样再生剂量协议进行光学激发发光测年,以提高川东洞沉积序列的年代学精度。使用贝叶斯建模方法确定每层的年龄,该方法将光学刺激的发光年龄与已发布的AMS14C日期相结合。结果表明,第10层从56±14ka开始积累,并为序列中的所有伪影提供了年龄上限。来自第8层的骨锥工具,是该部位最早的磨骨工具,在40±7ka和30±4ka之间的沉积物中回收。第8层还显示了川东洞穴序列中现代人的外观。第4-2层,范围从15±3ka到11±1ka,包括YoungerDryas时期,里面有几个骨头锥子和一个带眼的骨头针.川洞序列从骨锥到眼骨针的转变表明,现代人类适应了中国南方不断变化的气候。我们得出的结论是,早在40±7ka时,中国南方就出现了现代人类在骨工具中的行为,在最后一次冰川高峰期间变得更加复杂,并在年轻树干期间在中国南方更广泛地传播。
    Chuandong Cave is an important Late Paleolithic site because it documents the early appearance of bone tools in southern China. We used the single-aliquot regenerative-dose protocol for optically stimulated luminescence dating to improve the precision of the chronology for the Chuandong Cave sedimentary sequence. The age of each layer was determined using a Bayesian modeling approach which combined optically stimulated luminescence ages with published AMS 14C dates. The results showed that Layer 10 began accumulating since 56 ± 14 ka and provides the upper age limit for all artifacts from the sequence. Bone awl tools from Layer 8, the earliest grinding bone tools in this site, were recovered within sediments between 40 ± 7 ka and 30 ± 4 ka. Layer 8 also indicates the appearance of modern humans in the Chuandong Cave sequence. Layers 4-2, ranging from 15 ± 3 ka until 11 ± 1 ka and including the Younger Dryas period, contain a few bone awls and an eyed bone needle. The shift from bone awls to eyed bone needles in the Chuandong Cave sequence indicates that modern humans adapted to the changing climate of southern China. We conclude that modern human behavior in bone tools appeared in southern China as early as 40 ± 7 ka, became more sophisticated during the Last Glacial Maximum, and spread more widely across southern China during the Younger Dryas.
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  • 文章类型: Journal Article
    流动游牧是西北青铜时代和铁器时代的重要生活方式,在区域社会文化发展中起着至关重要的作用,以及跨地区网络的形成。在本文中,我们分析了石人子沟F2屋的完整动物区系组合,在天山东部,结合放射性碳测年和空间分析,探讨当地动物资源开发策略及相关社会经济意义。我们的结果显示了强化的多用途山羊管理,在开发其他国内分类群的同时,牛,马和狗,是有限的。这种田园经济补充了一些狩猎。F2中空间的差异化使用表明,基本的国内任务是在结构中执行的,然而,它在景观中的地位和与战争和社交活动相关的骨骼工具的优势,这表明它不是一个普通的住宅,它也可能是沟渠内夏季营地的监视站。我们的发现对公元前一千年后期东天山地区动物资源开发策略及其与不断发展的社会经济复杂性的关系的讨论做出了重要贡献。
    Mobile pastoralism was a key lifeway in the Late Bronze and Iron Age of Northwest China and played a crucial role in the regional socio-cultural development, as well as the formation of transregional networks. In this paper we analyse the complete faunal assemblage from House F2 in Shirenzigou, on the Eastern Tianshan Mountains, in combination with radiocarbon dating and spatial analysis, to explore local animal resources exploitation strategies and related socio-economic implications. Our results show an intensive multipurpose caprine management, while the exploitation of other domestic taxa, cattle, horses and dogs, was limited. This pastoral economy was supplemented with some hunting. The differentiated use of space in F2 indicates that basic domestic tasks were carried out in the structure, however its position within the landscape and the predominance of bone tools related to warfare and socialization activities, suggests that it was not an ordinary dwelling, it may also have served as a watch post for the summer encampment within the gully. Our findings constitute an important contribution on the discussion on animal resources exploitation strategies and their relationship with evolving socio-economic complexity in the Eastern Tianshan region in the late first millennium BCE.
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  • 文章类型: Journal Article
    来自青藏高原西北部(NWTP)的冰芯包含长期的区域气候变异性记录,但是这些核心中重新冻结的融水和灰尘阻碍了强劲时间尺度的发展。这里,我们介绍了一种通过气泡中大气O2的同位素组成(δ18Oatm)来测年冰的方法,以及年度层数和放射性碳测年。我们为NWTP中Guliya冰盖的三个冰芯提供了可靠的水同位素记录(δ18Oice和d-过量)。δ18Oatm的测量,尽管在极地冰芯时间尺度中很常见,很少在低纬度的冰芯上使用,高海拔冰川由于(1)低气压,(2)常见的再冷冻熔体的存在,增加了溶解的气体,减少了可用于分析的空气量,(3)冰中微生物对分子氧(O2)的呼吸消耗,从大气值中分馏O2的δ18O。这里,我们对融化和呼吸进行校正以解决这些并发症。古利亚冰芯的水同位素记录显示了过去15,000年的气候变化,其时间与在独立年代的湖泊和speleothem记录中观察到的时间相对应,并确认在全新世之前存在古利亚冰盖。δ18Oice的千年尺度驱动因素是复杂且随时间变化的;然而,自20世纪中叶以来的Guliyaδ18Oice值是全新世以来的最高值,并且随着区域气温的增加而增加。
    Ice cores from the northwestern Tibetan Plateau (NWTP) contain long records of regional climate variability, but refrozen meltwater and dust in these cores has hampered development of robust timescales. Here, we introduce an approach to dating the ice via the isotopic composition of atmospheric O2 in air bubbles (δ18Oatm), along with annual layer counting and radiocarbon dating. We provide a robust chronology for water isotope records (δ18Oice and d-excess) from three ice cores from the Guliya ice cap in the NWTP. The measurement of δ18Oatm, although common in polar ice core timescales, has rarely been used on ice cores from low-latitude, high-altitude glaciers due to (1) low air pressure, (2) the common presence of refrozen melt that adds dissolved gases and reduces the amount of air available for analysis, and (3) the respiratory consumption of molecular oxygen (O2) by micro-organisms in the ice, which fractionates the δ18O of O2 from the atmospheric value. Here, we make corrections for melt and respiration to address these complications. The resulting records of water isotopes from the Guliya ice cores reveal climatic variations over the last 15,000 y, the timings of which correspond to those observed in independently dated lake and speleothem records and confirm that the Guliya ice cap existed before the Holocene. The millennial-scale drivers of δ18Oice are complex and temporally variable; however, Guliya δ18Oice values since the mid-20th century are the highest since the beginning of the Holocene and have increased with regional air temperature.
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  • 文章类型: Journal Article
    Ice cores from alpine glaciers are unique archives of past global and regional climate conditions. However, recovering climate records from these ice cores is often hindered by the lack of a reliable chronology, especially in the age range of 100 to 500 anni (a) for which radiometric dating has not been available so far. We report on radiometric 39Ar dating of an ice core from the Tibetan Plateau and the construction of a chronology covering the past 1,300 a using the obtained 39Ar ages. This is made possible by advances in the analysis of 39Ar using the laser-based detection method atom trap trace analysis, resulting in a twofold increase in the upper age limit of 39Ar dating. By measuring the anthropogenic 85Kr along with 39Ar we quantify and correct modern air contamination, thus removing a major systematic uncertainty of 39Ar dating. Moreover, the 85Kr data for the top part of the ice core provide information on firn processes, including the age difference between the ice and its enclosed gas. This first application of 39Ar and 85Kr to an ice core facilitates further ice cores from nonpolar glaciers to be used for recovering climate records of the Common Era, a period including pronounced anomalies such as the Little Ice Age and the Medieval Warm Period.
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