scholarly journals Relative paleointensity of the geomagnetic field over the last 21,000 years BP from sediment cores, Lake El Trébol (Patagonia, Argentina)

2006 ◽  
Vol 58 (10) ◽  
pp. 1323-1332 ◽  
Author(s):  
C. S. G. Gogorza ◽  
M. A. Irurzun ◽  
M. A. E. Chaparro ◽  
J. M. Lirio ◽  
H. Nunez ◽  
...  
2020 ◽  
Author(s):  
Jiabo Liu ◽  
Norbert Nowaczyk ◽  
Xufeng Zheng ◽  
Qinsong Liu ◽  
Helge Arz

<p>Paleomagnetic records reconstructed from globally distributed marine sediments have greatly improved our understanding of long-term paleosecular variations and geomagnetic excursions. Nevertheless, questions regarding to the development of the geomagnetic field anomaly in the Southern Atlantic Ocean and the asymmetric geomagnetic field between Northern and Southern Hemispheres are not yet satisfactorily resolved. Paleomagnetic data, particularly from the Southern Hemisphere, is needed to better define the global geomagnetic field configurations spanning paleosecular variations and excursions. In this study, three sediment cores (PS97-085, PS97-84, PS97-079) recovered from the Drake Passage, Southern Ocean were subjected to detailed rock magnetic and paleomagnetic investigations. Preliminary age models were obtained by correlating their magnetic susceptibility to the ẟ<sup>18</sup>O master record from Dome C, Antarctica. In addition, rock magnetic records of the studied PS97 cores were further correlated to that of core PS67/197-1 with AMS <sup>14</sup>C age constraints. The results from PS97 cores are thus continuously covering the past about 110 ka. Rock magnetic results indicate titanomagnetite is the dominant magnetic carrier in the studied PS97 cores. Relative paleointensities (RPI) derived from these PS97 cores are comparable with the regional relative paleointensity records and the South Atlantic paleointensity stack (SAPIS). Additionally, anomalous inclinations at about 41 ka and 35 ka, observed in core PS97-085, are coeval with the Laschamps and the Mono Lake excursions, respectively. This study provides new paleomagnetic records from the Southern Ocean, though further age constrains are needed to consolidate the paleomagnetic interpretations. The up to now obtained paleomagnetic records, together with previous studies from the Southern Ocean, are aiming to clarify the asymmetric pattern of non-dipole geomagnetic field between Northern and Southern Hemispheres.</p>


1997 ◽  
Vol 152 (1-4) ◽  
pp. 11-23 ◽  
Author(s):  
Andrew P. Roberts ◽  
Benoı̂t Lehman ◽  
Robin J. Weeks ◽  
Kenneth L. Verosub ◽  
Carlo Laj

2008 ◽  
Vol 45 (11) ◽  
pp. 1265-1281 ◽  
Author(s):  
Francesco Barletta ◽  
Guillaume St-Onge ◽  
James E.T. Channell ◽  
André Rochon ◽  
Leonid Polyak ◽  
...  

Two piston cores recovered from the Chukchi and the Beaufort seas document Arctic Holocene geomagnetic field behaviour and highlight the potential of secular variation and relative paleointensity as a regional chronostratigraphic tool. Several centennial- to millennial-scale Holocene declination and inclination features can be correlated in both cores, with other high-resolution western North American lacustrine and volcanic paleomagnetic records and with records of changes in Earth’s dipole moment, supporting the geomagnetic origin of these features and implying that they are associated with changes in Earth’s dipole moment.


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