Geomagnetic paleointensity dating of South China Sea sediments for the last 130 kyr

Yang, Xiaoqiang; Heller, Friedrich; Wu, N.; Yang, Jie; Su, Zhihua

doi:10.1016/j.epsl.2009.04.035

Cited by 28 publications

(11 citation statements)

References 43 publications

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“…Here, we correlate the geomagnetic RPI curves between the two cores and link them to the published reference RPI curves (Channell et al, 2009;Laj et al, 2004;Yang, Heller, Wu, et al, 2009; Figure 6) to refine and determine the chronostratigraphy of the two cores based on the age-depth model of Zhao et al (2021). Meanwhile, the susceptibility correlation between two cores is also performed (Figure S6b in Supporting Information S1).…”

Section: Stratigraphic Correlation and Chronostratigraphymentioning

confidence: 99%

“…These analyses demonstrate the different IRM values for the 30-50 mT field, which represents the stable remanence and as a normalizer effectively removes the magnetic mineral contribution from RPI records. (Channell et al, 2009) and SCS-PIS (Yang, Heller, Wu, et al, 2009) based on the accelerator mass spectrometry 14 C constraints and the δD wax age-depth model (Zhao et al, 2021).…”

Section: Rpi Reconstruction and Possible Influence Of Magnetic Proper...mentioning

confidence: 99%

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Paleosecular Variations During the Last Glacial Period From Tengchong Qinghai Lake, Yunnan Province, China

Yang

Zhang

et al. 2022

JGR Solid Earth

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In recent years, the evolution of the magnetic flux lobes in terms of location and intensity has been attributed to paleosecular variation of the geomagnetic field, reflecting outer‐core fluid convection close to the core‐mantle boundary. However, most results were based on observational data for the past 400 years supplemented by sparse archeomagnetic studies with data for approximately 3 kyr. In this paper, we construct a relative paleointensity (RPI) record and an inclination record spanning the past ∼90 kyr based on two cores from Tengchong Qinghai Lake (Yunnan Province, China), a closed crater lake that formed in the late Pleistocene. The evolution of flux lobes and the non‐dipole field can be assessed on a much longer time scale. Although the concentration and domain state of magnetic grains in the cores vary significantly, the RPI record is still representative of geomagnetic field features in the region of Yunnan Province, China. The contrasting trends in RPI with the records for eastern China since the late Holocene indicate the southeastward migration of the Siberian flux lobe. During the last glacial period, the RPI records of Tengchong Qinghai Lake and the North Atlantic Ocean show opposite trends, denoting the diverse and strong influence of the two flux lobe systems. The strong reverse flux lobe in the North Atlantic Ocean strengthened the non‐dipole field, while the weak normal flux lobe in Tengchong weakened the non‐dipole field.

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Section: Stratigraphic Correlation and Chronostratigraphymentioning

confidence: 99%

Section: Rpi Reconstruction and Possible Influence Of Magnetic Proper...mentioning

confidence: 99%

Paleosecular Variations During the Last Glacial Period From Tengchong Qinghai Lake, Yunnan Province, China

Yang

Zhang

et al. 2022

JGR Solid Earth

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“…ages, the oxygen isotope stratigraphy, and relative paleointensity (Laj et al, 2004;Yang et al, 2009; Figure 8A). We can correlate the pattern between our data and reference curves.…”

Section: Refining the Chronology Of The Profilementioning

confidence: 99%

“…The (Imbrie and McIntyre, 2006) and oxygen isotope stratigraphy of ODP1144 site (Bühring et al, 2004). (A), Calibrated AMS 14 C ages were also listed along depth; In (B), the relative paleointensity variations was comparison with the standard curve GLOPIS-75 (Laj et al, 2004) and the stacked curve of the north of South China Sea (Yang et al, 2009). Red dotted lines indicate the tied points synchronous in relative intensity and oxygen isotope.…”

Section: Nrm Directions and Relative Intensitymentioning

confidence: 99%

“…The age model of the reference ODP 1144 core was constructed on the oxygen isotopes of G. ruber and four AMS 14 C dates on G. ruber and G. sacculifer mixtures by Bühring et al (2004), which provided a reliable chronology. The reference paleointensity curve NH-PIS was presented by Yang et al (2009). The chronology of our profile was constrained by eight tied points integrating three AMS 14 C ages, suggesting that the sediments in the ∼410 cm long record the deposition of about 90 kyr.…”

Section: Refining the Chronology Of The Profilementioning

confidence: 99%

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Chemical Weathering Intensity and Terrigenous Flux in South China during the Last 90,000 Years—Evidence from Magnetic Signals in Marine Sediments

et al. 2016

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The level of chemical weathering is strongly affected by climate. We presented magnetic properties associated with element ratios from the northern part of the South China Sea to denote links between chemical weathering intensity and monsoon changes in the previous 90,000 years. The magnetic parameter IRM AF80mT /SIRM, representing the variations of high coercivity minerals in marine sediments accompanied with the Al 2 O 3 /TiO 2 and the Chemical Index of Alteration (CIA), demonstrates strong chemical and physical weathering processes during the last 84-40 kyr when intensified Asian monsoon and warm climate occurred. High susceptibility, TiO 2 content, and relatively coarser magnetic mineral grain (relatively low ARM/SIRM ratio) also suggest more terrigenous clastic flux resulting from intensified physical erosion and river transport ability. During the 40-15 kyr period, a low IRM AF80mT /SIRM as well as chemical proxies indicate weak weathering as the climate cooled and precipitation decreased.

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Variable remanence acquisition efficiency in sediments containing biogenic and detrital magnetites: Implications for relative paleointensity signal recording

Ouyang

Heslop

Roberts

et al. 2014

Geochem Geophys Geosyst

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Widespread geological preservation of biogenic magnetite makes it important to assess how such particles contribute to sedimentary paleomagnetic signals. We studied a sediment core from the South China Sea that passes the strict empirical criteria for magnetic ''uniformity'' used in relative paleointensity studies. Such assessments are based routinely on bulk magnetic parameters that often fail to enable identification of mixed magnetic mineral assemblages. Using techniques that enable component-specific magnetic mineral identification, we find that biogenic and detrital magnetites occur in approximately equal concentrations within the studied sediments. We analyzed normalized remanence signals associated with the two magnetite components to assess whether co-occurring biogenic and detrital magnetites record geomagnetic information in the same way and with the same efficiency. Paleomagnetic directions for the two components have no phase lag, which suggests that the biogenic and detrital magnetites acquired their magnetizations at equivalent times. However, we find that the biogenic magnetite is generally 2-4 times more efficient as the detrital magnetite in contributing to the natural remanent magnetization (NRM) despite their approximately equal magnetic contributions. Variations in the concentration and efficiency of remanence acquisition of the two components suggest that a significant part of the NRM is controlled by nongeomagnetic factors that will affect relative paleointensity recording. We recommend that methods suited to the detection of variable recording efficiency associated with biogenic and detrital magnetites should be used on a routine basis in relative paleointensity studies.

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Geomagnetic paleointensity dating of South China Sea sediments for the last 130 kyr

Cited by 28 publications

References 43 publications

Paleosecular Variations During the Last Glacial Period From Tengchong Qinghai Lake, Yunnan Province, China

Paleosecular Variations During the Last Glacial Period From Tengchong Qinghai Lake, Yunnan Province, China

Chemical Weathering Intensity and Terrigenous Flux in South China during the Last 90,000 Years—Evidence from Magnetic Signals in Marine Sediments

Variable remanence acquisition efficiency in sediments containing biogenic and detrital magnetites: Implications for relative paleointensity signal recording

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