DOI: 10.1016/j.epsl.2018.01.004
Scopus记录号: 2-s2.0-85044723084
论文题名: Sr–Nd–Hf isotopic fingerprinting of transatlantic dust derived from North Africa
作者: Zhao W. ; Balsam W. ; Williams E. ; Long X. ; Ji J.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 486 起始页码: 23
结束页码: 31
语种: 英语
英文关键词: clay-sized fractions
; deserts
; dust
; North Africa
; Sr–Nd–Hf isotope
Scopus关键词: Arid regions
; Atmospheric movements
; Isotopes
; Clay-sized fractions
; deserts
; Geochemical fingerprints
; Hf isotope
; Isotopic composition
; Isotopic fingerprinting
; Long range transport
; North Africa
; Dust
; desert
; dust
; hafnium
; isotopic composition
; long range transport
; neodymium isotope
; particle size
; strontium isotope
; Benin [West Africa]
; Egypt
; Mali
; Morocco
; Sahara
; Togo
英文摘要: Long-range transport of African dust plays an important role in understanding dust-climate relationships including dust source areas, dust pathways and associated atmospheric and/or oceanic processes. Clay-sized Sr–Nd–Hf isotopic compositions can be used as geochemical fingerprints to constrain dust provenance and the pathways of long-range transported mineral dust. We investigated the clay-sized Sr–Nd–Hf isotopic composition of surface samples along four transects bordering the Sahara Desert. The transects are from Mali, Niger/Benin/Togo, Egypt and Morocco. Our results show that the Mali transect on the West African Craton (WAC) produces lower εNd (εNd-mean = −16.38) and εHf (εHf-mean = −9.59) values than the other three transects. The Egyptian transect exhibits the lowest 87Sr/86Sr ratios (87Sr/86Srmean = 0.709842), the highest εHf (εHf-mean = −0.34) and εNd values of the four transects. Comparison of the clay-sized Sr–Nd–Hf isotopic values from our North African samples to transatlantic African dust collected in Barbados demonstrates that the dust's provenance is primarily the western Sahel and Sahara as well as the central Sahel. Summer emission dust is derived mainly from the western Sahel and Sahara regions. The source of transatlantic dust in spring and autumn is more varied than in the summer and includes dust not only from western areas, but also south central areas. Comparison of the Sr–Nd–Hf isotopic fingerprints between the source and sink of transatlantic dust also suggests that a northwestward shift in dust source occurs from the winter, through the spring and into the summer. The isotopic data we develop here provide another tool for discriminating changes in dust archives resulting from paleoenvironmental evolution of source regions. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110021
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Key Laboratory of Earth Surface Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210046, China; School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210046, China; Department of Earth Sciences, Dartmouth College, Hanover, NH, United States; Massachusetts Institute of Technology, Cambridge, MA 02139-4307, United States; College of Geographical Science, Southwest University, Chongqing, China
Recommended Citation:
Zhao W.,Balsam W.,Williams E.,et al. Sr–Nd–Hf isotopic fingerprinting of transatlantic dust derived from North Africa[J]. Earth and Planetary Science Letters,2018-01-01,486