DOI: 10.1016/j.quascirev.2018.05.007
Scopus记录号: 2-s2.0-85047129946
论文题名: Relative paleointensity (RPI) in the latest Pleistocene (10–45 ka) and implications for deglacial atmospheric radiocarbon
作者: Channell J.E.T. ; Hodell D.A. ; Crowhurst S.J. ; Skinner L.C. ; Muscheler R.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 191 起始页码: 57
结束页码: 72
语种: 英语
英文关键词: Atmospheric radiocarbon
; Carbon cycle
; Ice-core 10Be
; Latest Quaternary
; Relative geomagnetic paleointensity
; SW Iberian margin
; “Mystery interval”
Scopus关键词: Atmospheric chemistry
; Beryllium compounds
; Coercive force
; Drops
; Geomagnetism
; Glacial geology
; Hematite
; Magnetite
; Magnetization
; Natural resources management
; Reflection
; Carbon cycles
; Ice core
; Latest Quaternary
; Paleointensity
; SW Iberian margin
; Ice
英文摘要: We report magnetic properties and relative paleointensity (RPI) proxies from a suite of 10 conventional piston cores and Kasten cores from the SW Iberian Margin collected during cruise JC089 of the RSS James Cook in August 2013. Mean sedimentation rates are in the 10–20 cm/kyr range. Age models were acquired by correlation of Ca/Ti and Zr/Sr XRF core-scanning data to L* reflectance from the Cariaco Basin that is, in turn, tied to the Greenland ice-core chronology. The natural remanent magnetization (NRM) is represented by a single magnetization component carried by a low-coercivity mineral (magnetite), although reflectance and bulk magnetic properties indicate the presence of a high-coercivity (hematitic) magnetic phase, possibly from eolian dust. The presence of fine-grained hematite means that the sediments are not ideal for RPI studies, however the detrital hematite does not appear to contribute to the NRM or anhysteretic remanent magnetization (ARM). In order to test the usefulness of the RPI data, we construct a stack of 12 RPI records from the SW Iberian Margin for the 0–45 ka interval and compare it with a stack of 12 globally distributed marine and lake records, chosen on the basis of mean sedimentation rates (>15 cm/kyr) and superior age models. The two stacks are similar, but different from published RPI stacks, particularly for the 10–30 ka interval, and imply a virtual axial dipole moment (VADM) high at ∼15–18 ka followed by a drop in field strength from ∼15 to 13 ka. A revised VADM estimate calculated from Greenland 10Be ice-core flux using a contemporary age model is remarkably consistent with the new overall RPI stack, based on Iberian Margin and global RPI records. The elevated atmospheric 14C levels of the last ice age cannot, however, be fully explained by this RPI stack although relative changes such as the long-term drop in atmospheric 14C from 30 to 15 ka are reproduced, supporting the hypothesis of a combined influence of production rate and ocean ventilation on 14C during the last ice age. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112157
Appears in Collections: 气候减缓与适应
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作者单位: Department of Geological Sciences, University of Florida, 241 Williamson Hall, POB 112120, Gainesville, FL 32611, United States; Godwin Laboratory for Palaeoclimate Research, Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, United Kingdom; Department of Geology, Quaternary Sciences, Lund University, Sölvegatan 12, Lund, SE-223 62, Sweden
Recommended Citation:
Channell J.E.T.,Hodell D.A.,Crowhurst S.J.,et al. Relative paleointensity (RPI) in the latest Pleistocene (10–45 ka) and implications for deglacial atmospheric radiocarbon[J]. Quaternary Science Reviews,2018-01-01,191