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| Yamazaki, Toshitsugu; Kanamatsu, Toshiya. |
| A paleomagnetic study was conducted on a sediment core KR0310-PC1 taken from the central North Pacific in order to obtain a relative paleointensity record in the Matuyama chron from this region. The core reached to about 1.6 Ma. The age control is based on the correlation of the S ratio (S-0.1T) variations with a global oxygen-isotope stack. Isothermal remanent magnetization (IRM) was used as the normalizer of the relative paleointensity estimation; anhysteretic remanent magnetization (ARM) was not adopted because ARM is sensitive to magnetostatic interaction among magnetic particles, which is evidenced in these sediments by an inverse correlation between the ratio of ARM to saturation IRM (SIRM) and SIRM without significant magnetic grain-size changes.... |
| Tipo: Text |
Palavras-chave: Paleomagnetism; Paleointensity; North Pacific; Orbital modulation; Normalizer; Magnetostatic interaction. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34631/32963.pdf |
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| Stoner, Joseph S.; Channell, James E. T.; Mazaud, Alain; Strano, Sarah E.; Xuan, Chuang. |
| Paleomagnetic analysis and radiocarbon dating of an expanded Holocene deep-sea sediment sequence recovered by Integrated Ocean Drilling Program (IODP) Expedition 303 from Labrador Sea Site U1305 (Lat.: 57 degrees 28.5 N, Long.: 48 degrees 31.8 W, water depth 3459 m) provides insights into mechanisms that drive both paleomagnetic secular variation (PSV) and magnetization acquisition in deep-sea sediments. Seventeen radiocarbon dates on planktonic foraminifera define postglacial (ca. 8 ka) sedimentation rates as ranging from 35 to > 90 cm/kyr. Alternating field (AF) demagnetization of u-channel samples show that these homogeneous sediments preserve a strong, stable, and consistently well-defined component magnetization. Normalized remanence records pass... |
| Tipo: Text |
Palavras-chave: Paleomagnetism; North Atlantic; Paleointensity. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37480/36500.pdf |
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| Zimmerman, Susan H.; Hemming, Sidney R.; Kent, Dennis V.; Searle, Stephanie Y.. |
| Lakes are highly sensitive recorders of climate processes, but are extremely difficult to correlate precisely to ice-core and marine records, especially in the absence of reliable radiocarbon dates. Relative paleointensity (RPI) of Earth's magnetic field is an independent method of correlating high-resolution climate records, and can be applied to both marine and terrestrial sediments, as well as (inversely) correlated to the cosmogenic nuclide records preserved in ice cores. Here we present the correlation of an RPI record from Mono Lake, California to GLOPIS, the Global PaleoIntensity Stack, which increases the age estimation of the basal Mono Lake sediments by > 20000 yr (20 kyr), from similar to 40 ka (kyr before present) to 67 ka. The Mono Lake... |
| Tipo: Text |
Palavras-chave: Paleointensity; GLOPIS; Argon; Great Basin; Mono Lake excursion; Laschamp. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34500/33454.pdf |
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| Valet, Jean-pierre; Moreno, Eva; Bassinot, Franck; Johannes, Lola; Dewilde, Fabien; Bastos, Tiago; Lefort, Apolline; Venec-peyre, Marie-therese. |
| High resolution measurements of climatic and magnetic parameters have been performed on two cores from the eastern China Sea and the western Caroline Basin. On both cores, magnetic parameters show a strong imprint of climatic changes but the absence of relationship between the inclination and the bulk density indicates that the directional changes do not depend on lithology. A weak 100 ka cycle is present in the China sea inclination variations, but this period is not in phase with the orbital eccentricity and thus not relevant. All normalization parameters yielded similar estimates of relative paleointensity (RPI), but we have noticed the persistence of climatic components in the signal. Principal Component Analysis (PCA) applied to different parameters... |
| Tipo: Text |
Palavras-chave: Magnetization; Paleointensity; Paleomagnetism; Sediments. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00227/33818/32481.pdf |
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| Evans, Helen F.; Channell, James E. T.; Stoner, Joseph S.; Hillaire-marcel, Claude; Wright, James D.; Neitzke, Lauren C.; Mountain, Gregory S.. |
| Four piston cores collected in 1999 and 2002 from the Eirik Drift (southern Labrador Sea, off SE Greenland) provide paleomagnetic, environmental magnetic, and oxygen isotope records back to marine isotope stage 11. Age models for the cores are based on a combination of planktonic oxygen isotope data, relative geomagnetic paleointensity proxies, and the identification of geomagnetic excursions (Laschamp and Iceland Basin). Environmental magnetic data delineate two distinct detrital signals, interpreted to reflect the behavior of the surrounding ice sheets (Greenland and Laurentide) to orbital-and millennial-scale climate forcing. Broad decimeter-scale intervals of increased magnetic concentration and grain size occur during the early part of interglacial... |
| Tipo: Text |
Palavras-chave: Paleointensity. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34625/32978.pdf |
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| Okada, Makoto; Suganuma, Yusuke; Haneda, Yuki; Kazaoka, Osamu. |
| The youngest geomagnetic polarity reversal, the Matuyama-Brunhes (M-B) boundary, provides an important plane of data for sediments, ice cores, and lavas. The geomagnetic field intensity and directional changes that occurred during the reversal also provide important information for understanding the dynamics of the Earth's outer core, which generates the magnetic field. However, the reversal process is relatively rapid in terms of the geological timescale; therefore, adequate temporal resolution of the geomagnetic field record is essential for addressing these topics. Here, we report a new high-resolution paleomagnetic record from a continuous marine succession in the Chiba composite section of the Kokumoto Formation of the Kazusa Group, Japan, that... |
| Tipo: Text |
Palavras-chave: Paleomagnetism; Magnetostratigraphy; Matuyama-Brunhes boundary; Paleointensity; Marine isotope stage (MIS) 19; Chiba composite section. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53174/55181.pdf |
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| Yamazaki, T; Oda, H. |
| We have conducted a paleomagnetic study of six sediment cores taken from the equatorial Pacific, three from the West Caroline Basin and three from the Manihiki Plateau, in order to make a relative paleointensity stack during the Matuyama and late Gauss Chrons. The age of the bottom of the cores ranges from 1.2 to 3.0 Ma. The sediments show little downcore changes in the proxies of magnetic grain size and mineralogy and are hence suitable for estimating relative paleointensity. The age of the cores is controlled by correlating variations in magnetic concentration ( magnetic susceptibility and/or anhysteretic remanent magnetization (ARM)) to target oxygen-isotope (delta(18)O) curves. All cores from the Manihiki Plateau show an upward decrease of the natural... |
| Tipo: Text |
Palavras-chave: Equatorial Pacific; Excursion; Orbital modulation; Paleointensity; Paleomagnetism. |
| Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00232/34285/32650.pdf |
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| Carcaillet, Jt; Bourles, Dl; Thouveny, N. |
| A synthesis of authigenic Be-10/Be-9 ratio records constructed from sedimentary sequences deposited over the last 300 ka in the North East Atlantic and over the 500 - 1300 ka BP interval in the West Equatorial Pacific Ocean is compared with proxies of the geomagnetic moment variations over the same time intervals. These proxies consist in (1) relative paleointensity records obtained from the same sediments, (2) a seafloor magnetization record derived form magnetic anomalies, and (3) an absolute Virtual Dipole Moment (VDM) record constructed from an updated database of absolute paleointensities. The authigenic Be-10/Be-9 ratio records document the occurrence of the paleomagnetic events (excursions and reversals) reported for these time intervals by... |
| Tipo: Text |
Palavras-chave: Cosmogenic nuclide production rate; Beryllium; Paleointensity; Geomagnetic moment. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00229/34014/32371.pdf |
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