DOI: 10.1016/j.quascirev.2015.10.011
Scopus记录号: 2-s2.0-84946020162
论文题名: Relative paleointensity (RPI) and oxygen isotope stratigraphy at IODP Site U1308: North Atlantic RPI stack for 1.2-2.2 Ma (NARPI-2200) and age of the Olduvai Subchron
作者: Channell J.E.T. ; Hodell D.A. ; Curtis J.H.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 131 起始页码: 1
结束页码: 19
语种: 英语
英文关键词: Age of Olduvai Subchron
; Late Pliocene
; North Atlantic
; Quaternary
; Relative paleointensity
; Stable isotopes
Scopus关键词: Calibration
; Geomagnetism
; Magnetic polarity
; Oceanography
; Oxygen
; Sedimentation
; Stratigraphy
; Age of Olduvai Subchron
; Late Pliocene
; North Atlantic
; Quaternary
; Relative paleointensity
; Stable isotopes
; Isotopes
; depositional sequence
; geochronology
; geomagnetism
; magnetic reversal
; marine isotope stage
; oxygen isotope
; paleoceanography
; Pleistocene
; Pliocene
; sedimentation rate
; stable isotope
; stratigraphic correlation
; timescale
; Atlantic Ocean
; Atlantic Ocean (North)
; Porcupine Abyssal Plain
英文摘要: Integrated Ocean Drilling Program (IODP) Site U1308 (49°53'N, 24°14'W; water depth 3871 m) provides a record of relative paleointensity (RPI) and benthic stable isotope stratigraphy back to 3.2 Ma. The record since 1.5 Ma was published previously, and here we present the interval from 1.5 Ma to 3.2 Ma (Early Pleistocene-Late Pliocene). The benthic oxygen isotope record in this interval is correlated to Marine Isotope Stage (MIS) 51 to KM2, with an apparent hiatus that removed part of the interval spanning MIS 104-G2 (2.6-2.65 Ma), at the Gauss-Matuyama boundary. The mean sedimentation rate for the 1.5-3.2 Ma period is 8.5 cm/kyr. The age model was built by correlation of the benthic oxygen isotope record to a global stack (LR04). Apart from the expected polarity reversals, three magnetic excursions are recorded: Punaruu in MIS 31/32 at 1092 ka, Gilsa in MIS 54/55 at 1584 ka, and a newly recognized excursion labeled Porcupine (after the nearby Porcupine Abyssal Plain) in MIS G6/G7 at 2737 ka. The ages of polarity reversals at Site U1308, on the LR04 time scale, are consistent with the current geomagnetic polarity timescale (GPTS) with the exception of the base of the Olduvai Subchron that occurred in MIS 73, corresponding to 1925 ka on the LR04 time scale, 25 kyr younger than in the current GPTS. The RPI record at Site U1308 is calibrated using the oxygen isotope age model, and combined with four other North Atlantic records to obtain a North Atlantic RPI stack for 1.2-2.2 Ma (NARPI-2200) that is compared with published RPI stacks: Epapis, Sint-2000 and PADM2M. For 2.2-3.2 Ma, the Site U1308 RPI record is compared with a RPI record from North Atlantic IODP Site U1314, and with the Pacific Epapis stack. The mean sedimentation rates of the North Atlantic sites in NARPI-2200 are greater (by about an order of magnitude) than most of the records incorporated in other stacks. The comparison of Epapis and NARPI-2200 yields an apparent lag for NARPI-2200 relative to Epapis, attributed the Epapis age model constructed by correlation of magnetic concentration parameters (a proxy for carbonate percentage) to a calibrated oxygen isotope record. The long RPI record from Site U1308 yields a very similar mean value for the Brunhes and Matuyama virtual axial dipole moments (7.05 × 1022 Am2), implying no polarity bias in the strength of the main geomagnetic dipole, in contrast to interpretations from Sint-2000 and PADM2M. The results strengthen the case that RPI can be used to improve global stratigraphic correlation for sites with mean sedimentation rates up to several decimeters/kyr. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59746
Appears in Collections: 过去全球变化的重建
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作者单位: Dept. Geological Sciences, University of Florida, Gainesville, FL, United States; Godwin Laboratory for Palaeoclimate Research, Dept. Earth Sciences, University of Cambridge, Cambridge, United Kingdom
Recommended Citation:
Channell J.E.T.,Hodell D.A.,Curtis J.H.. Relative paleointensity (RPI) and oxygen isotope stratigraphy at IODP Site U1308: North Atlantic RPI stack for 1.2-2.2 Ma (NARPI-2200) and age of the Olduvai Subchron[J]. Quaternary Science Reviews,2016-01-01,131