The magnetic properties of the late Quaternary hemipelagic sediment from piston core BS77-15 taken in the Tyrrhenian Sea were investigated and the results compared with palaeoclimatic records. The magnetic mineralogy of the sediment was studied and the magnetic carriers were identified by their spectra of coercivity and unblocking temperature. Investigations of rock magnetic parameters such as the Natural Remanent Magnetization (NRM), the low-field magnetic susceptibility x, the frequency-dependent susceptibility xm, the acquisition of Anhysteretic Magnetization (ARM) and Isothermal Magnetization (IRM) and the Median Destructive Field (MDF) have established the downcore variations in terms of magnetic mineralogy, grain size and coercivity in the sediments. The rock magnetic parameters were compared with an alternative climatic record from the same core based on the faunal association of planktonic foraminifera. A significant correlation was found between faunal climatic record and xm. Together with the magnetic properties of the sediment this suggests that a palaeoclimatic signal is recorded by a fine-grained low-coercivity fraction of the magnetic minerals.
Magnetic properties of Pleistocene sediments from Mediterranean sea: a correlation with paleoclimatic record
LANCI, LUCA
;WEZEL, FORESE-CARLO
1995
Abstract
The magnetic properties of the late Quaternary hemipelagic sediment from piston core BS77-15 taken in the Tyrrhenian Sea were investigated and the results compared with palaeoclimatic records. The magnetic mineralogy of the sediment was studied and the magnetic carriers were identified by their spectra of coercivity and unblocking temperature. Investigations of rock magnetic parameters such as the Natural Remanent Magnetization (NRM), the low-field magnetic susceptibility x, the frequency-dependent susceptibility xm, the acquisition of Anhysteretic Magnetization (ARM) and Isothermal Magnetization (IRM) and the Median Destructive Field (MDF) have established the downcore variations in terms of magnetic mineralogy, grain size and coercivity in the sediments. The rock magnetic parameters were compared with an alternative climatic record from the same core based on the faunal association of planktonic foraminifera. A significant correlation was found between faunal climatic record and xm. Together with the magnetic properties of the sediment this suggests that a palaeoclimatic signal is recorded by a fine-grained low-coercivity fraction of the magnetic minerals.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
