DOI: 10.1016/j.epsl.2017.12.010
Scopus记录号: 2-s2.0-85038432026
论文题名: Detailed Jaramillo field reversals recorded in lake sediments from Armenia – Lower mantle influence on the magnetic field revisited
作者: Kirscher U. ; Winklhofer M. ; Hackl M. ; Bachtadse V.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 484 起始页码: 124
结束页码: 134
语种: 英语
英文关键词: Armenia
; paleomagnetism
; reversals
Scopus关键词: Geomagnetism
; Heat flux
; Magnetic fields
; Sediments
; Shear flow
; Armenia
; Core-mantle boundary
; Earth's magnetic field
; Large Low Shear Velocity Provinces (LLSVPs)
; Paleomagnetic record
; Paleomagnetic signals
; paleomagnetism
; reversals
; Magnetic polarity
; geological record
; heat flux
; lacustrine deposit
; lower mantle
; magnetic field
; magnetic reversal
; paleomagnetism
; reconstruction
; timescale
; Armenia [West Asia]
; Australia
; Pacific Ocean
; Pacific Ocean (Northwest)
; United States
英文摘要: While it is well established that the Earth's magnetic field is generated by a self sustaining dynamo that reversed its polarity at irregular intervals in the geological past, the very mechanisms causing field reversals remain obscure. Paleomagnetic reconstructions of polarity transitions have been essential for physically constraining the underlying mechanisms in terms of time scale, but thus far remain ambiguous with regard to the transitional field geometry. Here we present new paleomagnetic records from a rapidly deposited lacustrine sediment sequence with extraordinarily stable paleomagnetic signals, which has captured in unprecedented detail the bottom (reverse to normal: R–N) and top (normal to reverse: N–R) transitions of the Jaramillo subchron (at 1.072 Ma and at 0.988 Ma). The obtained virtual geomagnetic pole (VGP) path indicates an oscillatory transitional field behavior with four abrupt transequatorial precursory jumps across the Pacific. The distribution of VGP positions indicates regions of preferred occurrence. Our results are in agreement with previously proposed bands of transitional VGP occurrence over the Americas and Australia/northwest Pacific. Additionally, our VGP positions seem to avoid large low shear velocity provinces (LLSVPs) above the core mantle boundary (CMB). Thus, our data supports the idea that the transitional field geometry is controlled by heat flux heterogeneities at the CMB linked to LLSVPs. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110057
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: Earth Dynamics Research Group, ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS), The Institute for Geoscience Research (TIGeR), Department of Applied Geology, WASM, Curtin University, Perth, 6845, Australia; Department of Earth and Environmental Sciences, Geophysics, Ludwig-Maximilians University Munich, Theresienstr. 41, Munich, D-80333, Germany; Institute for Biological and Environmental Sciences IBU, University of Oldenburg, Oldenburg, D-26111, Germany; Allianz Reinsurance, Munich, Germany
Recommended Citation:
Kirscher U.,Winklhofer M.,Hackl M.,et al. Detailed Jaramillo field reversals recorded in lake sediments from Armenia – Lower mantle influence on the magnetic field revisited[J]. Earth and Planetary Science Letters,2018-01-01,484