Arid
DOI10.1016/j.quageo.2018.08.002
Coupling cosmogenic nuclides and luminescence dating into a unified accumulation model of aeolian landforms age and dynamics: The case study of the Kalahari Erg
Vainer, Shlomy; Ben Dor, Yoav; Matmon, Ari
通讯作者Vainer, Shlomy
来源期刊QUATERNARY GEOCHRONOLOGY
ISSN1871-1014
EISSN1878-0350
出版年2018
卷号48页码:133-144
英文摘要

Sand deposits cover extensive areas both in the northern and southern hemispheres and the timing and chronology and processes that govern their dynamics are of major interest. Luminescence-based dating methods, are used to date episodic aeolian events but are restricted to late Quaternary deposits, and only reveal the last cycle of sediment burial and not the time of sand existence in the landscape. Burial ages modelled from cosmogenic nuclides reach further back in time, but are usually inferred as minimal deposition ages. It is apparent that standard dating methods, when applied individually, have limited applicability for determining both the age and the processes that form aeolian deposits. This study presents an approach that integrates luminescence dating and cosmogenic burial dating into a stochastic model developed to reproduce sand formation and migration. The model is based on a process in which quartz grains are vertically displaced through a sand column simulating dune migration across the landscape. A range of vertical displacement rates is compiled from published luminescence ages of dated dune fields of varied settings throughout the world. Using these vertical movement rates, sand is recycled up and down a depth profile coupled with a step-wise calculations of cosmogenic nuclides accumulation and decay, alongside OSL signal accumulation. When the modelled sand grains are buried, their luminescence signal grows while Al-26 and Be-10 decay or accumulate as a function of their respective radioactive decay and production rate, which is governed by cosmic rays attenuation. When sand is exposed at the surface, the luminescence signal is reset and cosmogenic nuclide production is maximized. Each simulation is terminated when the modelled concentrations of Al-26 and Be-10 reach measured concentrations in actual sand samples. Luminescence data therefore provide the time since last exposure at the surface (i.e. the last depositional cycle), whereas the cosmogenic nuclides provide a long-term estimate of sand residence in the landscape reflecting also weathering and erosion of the source bedrock. The southern Kalahari dune field at Mamatwan, South Africa, is used as a case study to test the presented approach. Model results show that optically stimulated luminescence ages which range between 1 and 10 Ka, only reflect the last cycle of sand migration, while cosmogenic nuclides minimal burial ages are greater than 1 Ma. Furthermore, the simulation results indicate two peaks at 1.5-2.2 Ma and at 4.2-5.2 Ma, suggesting two main phases of sand introduction to the Kalahari during the Pliocene and Pleistocene. Finally, the modelled ages are concurrent with regional environmental and climatic events. The model presented in this study provides a powerful tool for estimating the emergence of sand in a given landscape, and also for understanding the dynamic evolution of any dune field and the mechanisms behind dune migration.


类型Article
语种英语
国家Israel
收录类别SCI-E ; SSCI
WOS记录号WOS:000453621600014
WOS关键词NAMIB SAND SEA ; IN-SITU ; SOUTHWESTERN KALAHARI ; BENGUELA CURRENT ; WONDERWERK CAVE ; DESERT ; SEDIMENTS ; AFRICA ; AL-26 ; BE-10
WOS类目Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向Physical Geography ; Geology
来源机构Hebrew University of Jerusalem
资源类型期刊论文
条目标识符http://119.78.100.177/qdio/handle/2XILL650/212425
作者单位Hebrew Univ Jerusalem, Fredy & Nadine Herrmann Inst Earth Sci, Edmond J Safra Campus Givat Ram, IL-91904 Jerusalem, Israel
推荐引用方式
GB/T 7714
Vainer, Shlomy,Ben Dor, Yoav,Matmon, Ari. Coupling cosmogenic nuclides and luminescence dating into a unified accumulation model of aeolian landforms age and dynamics: The case study of the Kalahari Erg[J]. Hebrew University of Jerusalem,2018,48:133-144.
APA Vainer, Shlomy,Ben Dor, Yoav,&Matmon, Ari.(2018).Coupling cosmogenic nuclides and luminescence dating into a unified accumulation model of aeolian landforms age and dynamics: The case study of the Kalahari Erg.QUATERNARY GEOCHRONOLOGY,48,133-144.
MLA Vainer, Shlomy,et al."Coupling cosmogenic nuclides and luminescence dating into a unified accumulation model of aeolian landforms age and dynamics: The case study of the Kalahari Erg".QUATERNARY GEOCHRONOLOGY 48(2018):133-144.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[Vainer, Shlomy]的文章
[Ben Dor, Yoav]的文章
[Matmon, Ari]的文章
百度学术
百度学术中相似的文章
[Vainer, Shlomy]的文章
[Ben Dor, Yoav]的文章
[Matmon, Ari]的文章
必应学术
必应学术中相似的文章
[Vainer, Shlomy]的文章
[Ben Dor, Yoav]的文章
[Matmon, Ari]的文章
相关权益政策
暂无数据
收藏/分享

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。