A high‐resolution paleomagnetic and rock magnetic study has been carried out on sediment cores collectedin glaciomarine silty‐clay sequences from the continental shelf and slope of the southern Storfjordentrough‐mouth fan, on the northwestern Barents Sea continental margin. The Storfjorden sedimentarysystem was investigated during the SVAIS and EGLACOM cruises, when 10 gravity cores, with a variablelength from 1.03 m to 6.41 m, were retrieved. Accelerator mass spectrometry (AMS) 14C analyses on24 samples indicate that the cores span a time interval that includes the Holocene, the last deglaciation phaseand in some cores the last glacial maximum. The sediments carry a well‐defined characteristic remanentmagnetization and have a valuable potential to reconstruct the paleosecular variation (PSV) of the geomagneticfield, including relative paleointensity (RPI) variations. The paleomagnetic data allow reconstructionof past dynamics and amplitude of the geomagnetic field variations at high northern latitudes (75°–76° N).At the same time, the rock magnetic and paleomagnetic data allow a high‐resolution correlation of thesedimentary sequences and a refinement of their preliminary age models. The Holocene PSV and RPIrecords appear particularly sound, since they are consistent between cores and they can be correlated tothe closest regional stacking curves (UK PSV, FENNOSTACK and FENNORPIS) and global geomagneticmodel for the last 7 ka (CALS7k.2). The computed amplitude of secular variation is lower than thatoutlined by some geomagnetic field models, suggesting that it has been almost independent from latitudeduring the Holocene.
A Holocene paleosecular variation record from the north-western Barents Sea continental margin
Lucchi R.;Rebesco M.;Camerlenghi A.
2011-01-01
Abstract
A high‐resolution paleomagnetic and rock magnetic study has been carried out on sediment cores collectedin glaciomarine silty‐clay sequences from the continental shelf and slope of the southern Storfjordentrough‐mouth fan, on the northwestern Barents Sea continental margin. The Storfjorden sedimentarysystem was investigated during the SVAIS and EGLACOM cruises, when 10 gravity cores, with a variablelength from 1.03 m to 6.41 m, were retrieved. Accelerator mass spectrometry (AMS) 14C analyses on24 samples indicate that the cores span a time interval that includes the Holocene, the last deglaciation phaseand in some cores the last glacial maximum. The sediments carry a well‐defined characteristic remanentmagnetization and have a valuable potential to reconstruct the paleosecular variation (PSV) of the geomagneticfield, including relative paleointensity (RPI) variations. The paleomagnetic data allow reconstructionof past dynamics and amplitude of the geomagnetic field variations at high northern latitudes (75°–76° N).At the same time, the rock magnetic and paleomagnetic data allow a high‐resolution correlation of thesedimentary sequences and a refinement of their preliminary age models. The Holocene PSV and RPIrecords appear particularly sound, since they are consistent between cores and they can be correlated tothe closest regional stacking curves (UK PSV, FENNOSTACK and FENNORPIS) and global geomagneticmodel for the last 7 ka (CALS7k.2). The computed amplitude of secular variation is lower than thatoutlined by some geomagnetic field models, suggesting that it has been almost independent from latitudeduring the Holocene.File | Dimensione | Formato | |
---|---|---|---|
Sagnotti&al2011_G3.pdf
non disponibili
Tipologia:
Altro materiale allegato
Licenza:
Non specificato
Dimensione
4.07 MB
Formato
Adobe PDF
|
4.07 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.