The Xujiayao-Houjiayao site in Nihewan Basin is among the most important Paleolithic sites in China for having provided a rich collection of hominin and mammalian fossils and lithic artifacts. Based on biostratigraphical correlation and exploratory results from a variety of dating methods, the site has been widely accepted as early Upper Pleistocene in time. Two quartz samples from a lower cultural horizon give a weighted mean age of 0. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: All relevant data are within the paper and its Supporting Information files. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. While the first stone artifacts were discovered at the former locality, it is from the latter locality that an overwhelming majority of th e archaeological materials have been recovered, which include 19 hominin fossils traditionally assigned to archaic Homo sapiens , more than 30, lithic artifacts and an abundance of mammalian fossils [ 1 — 5 ]. Almost all of the publications and chronological studies have dealt with the latter locality. This explains why the site was initially named Xujiayao, but later renamed Xujiayao-Houjiayao by the State Administration of Cultural Heritage of China and simply as Houjiayao by the archaeologists in Hebei Province.
Cosmogenic nuclide dating
This proposal seeks funding for measurement of the cosmogenic radionuclides 26Al and 10Be in quartz from core and outcrop of Plio-Pleistocene sediment within and near Unaweep Canyon. The Plio-Pleistocene sediments were newly mapped in , and the core was collected in Our preliminary data indicate that Unaweep Canyon is a Paleozoic landform buried by later Paleozoic and Mesozoic sediments and then re-exhumed during the Cenozoic, a controversial claim.
Despite considerable age-dating efforts in our previous research, we have found no material in this sedimentary succession that can be dated using conventional methods.
surficial rocks and sediments can be assessed. The six most commonly used cosmogenic isotopes, 10Be, 26Al, 36Cl, 14C,. 3He and 21Ne, have allowed dating.
Only the ages of lower terraces were previously delimited by 14C. The highest elevation terraces T 8 , T 9 were sampled for cosmogenic 26AlBe burial dating to delimit the ages of previously identified faults, and possibly locate evidence of faults that may displace the terraces. Samples were collected from four locations 5 samples in each location, 20 samples total on both the north and south sides of the reservoir near previously identified faults. Session No. These faults have NE-striking, SE-dipping orientations, contain characteristic red sandy clay-filled fault gouge, and are a part of deformation zone.
Geological Society of America Abstracts with Programs. Permission is hereby granted to the author s of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information.
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Surface exposure dating
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area from cosmogenic 26Al and 10Be ratios. Stephanie Neuhuber. – Implications of inherited isotope concentrations when dating landslides with.
Assessment of vertical movements of tectonically bounded blocks is crucial for determination of geohazards in densely inhabited zones, such as the border zone of western Slovakia and eastern Austria. The structural research revealed predisposition of forming of horizontal passages in low angle to subhorizontal bedrock stratification together with low-grade metamorphic foliation.
Fluvial origin of the passages was inferred from mezoscale erosional features on the bedrock as well as from facies character of the well preserved sedimentary profile. Three analysed dating samples provided low values of isotopic concentrations, allowing us only to calculate the minimum burial age of the deposit of 1. The slow incision of the river network. In contrast are relatively high values of palaeodenudation rates inferred from isotopic concentrations. Strukturna raziskava je razkrila predispozicijo oblikovanja vodoravnih jamskih rovov pod nizkim kotom v odvisnosti od subhorozontalne stratifikacije kamnine ter tudi z nizko stopnjo metamorfne foliacije.
Na fluvialno poreklo rovov smo sklepali iz srednje velikih erozijskih oblik na njihovih stenah kot tudi iz lastnosti faciesov dobro ohranjenega sedimentnega profila. V nasprotju pa so sorazmerno visoke. Authors guarantee that the work is their own original creation and does not infringe any statutory or common-law copyright or any proprietary right of any third party.
In Situ-Produced Cosmogenic Nuclides and Quantification of Geological Processes
Nishiizumi, C. Kohl, J. Arnold, Ronald Dorn , I. Klein, D.
One particularly widely applied system compares the ratio of 26Al to 10Be in samples that have been exposed at the surface of the earth and then buried. While this ratio has been estimated before, its value is not well known and appears to vary around the world. The new data will also allow much better understanding of the uncertainty of these ages.
This work will train a graduate student in science and will improve dates of ancient human remains as well as past changes in Earth’s climate, including the coming and going of glaciers. The team will do this by making high-precision 26Al analyses of archived samples already prepared and previously analyzed for 10Be. The project will increase the broader impact of this work by disseminating the results both at meetings and in at least one peer-reviewed publication.
Additional broader impacts include training a student who will do much of the research and writing. This award reflects NSF’s statutory mission and has been deemed worthy of support through evaluation using the Foundation’s intellectual merit and broader impacts review criteria. Some full text articles may not yet be available without a charge during the embargo administrative interval.
TRAINING COURSE IN QUATERNARY GEOCHRONOLOGY
How can we date rocks? Using cosmogenic nuclides in glacial geology Sampling strategies cosmogenic nuclide dating Difficulties in cosmogenic nuclide dating Calculating an exposure age Further Reading References Comments. Geologists taking rock samples in Antarctica for cosmogenic nuclide dating. They use a hammer and chisel to sample the upper few centimetres of the rock. Cosmogenic nuclide dating can be used to determine rates of ice-sheet thinning and recession, the ages of moraines, and the age of glacially eroded bedrock surfaces.
Although 26Al/10Be dating has been widely applied (and many of the applications have been supported by NSF), the 26Al/10Be ratio at.
A Nature Research Journal. The Yiyuan hominin fossil site is one of the few localities in China where a partial skullcap and several loose teeth of Homo erectus have been discovered. Here, we report the first application of a radio-isotopic dating method to the site. The reliability of this age is supported by the zero age of modern fluvial sediment near the cave.
The results presented here, along with other recent chronological studies on Chinese Middle Pleistocene hominin sites, indicate that the time span from — ka thousand years ago is a critical period for human evolution in East Asia. Importantly, this time bracket includes several major climatic changes that would have influenced hominins, both morphologically and behaviorally.
The emergence of anatomically modern humans in eastern Asia continues to be a highly important topic within paleoanthropology 1 , 2. Recently, evidence has been presented that suggests early modern humans were present in this region as early as ka refs 3 , 4 , 5 , 6 , 7 , 8. However, the evolutionary history of the Middle Pleistocene hominin lineages preceding the appearance of Homo sapiens in eastern Asia remains controversial 9 , 10 , 11 , 12 , 13 , 14 , 15 ,
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Abstract The assumed value for the cosmogenic 26Al/10Be surface production rate ratio in quartz is an important parameter for studies.
The interaction of cosmic radiation with terrestrial matter leads to the in-situ production of cosmogenic nuclides in the exposed surface material. Accelerator mass spectrometry AMS enables us to quantitatively measure trace concentrations of in-situ produced radionuclides like 10 Be and 26 Al. This ultimately allows the determination of surface exposure ages, erosion rates and other processes of landscape evolution. The availability of a pure and well defined mineral sample is an important prerequisite for surface exposure dating.
As the samples taken in the field usually do consist of many different mineral components, a quartz separation technique has to be employed. We present a chemical mineral separation that allows the isolation of a pure quartz fraction, which is quantitatively decontaminated from the atmospheric 10 Be contamination lying on the sample. The journal is geared toward scientists who are actively engaged in research work.