A Holocene palaeomagnetic secular variation record from Huguangyan maar Lake, southern China.

SUMMARY A composite Holocene sediment profile ∼5 m in length, constrained by both radiocarbon dating and magnetic susceptibility based correlation, was obtained from three Livingstone piston cores collected in ∼10-m water depth in the Huguangyan (HGY) maar lake, southern China. The homogeneous silty clay indicates stable and continuous deposition. The dominant magnetic carrier is magnetite in the pseudo-single-domain grain size range and thus is suitable for recording palaeomagnetic secular variations (PSV). Results show that the HGY PSV curves can be correlated faithfully to the counterparts at a regional scale. Therefore, the PSV data is a potential tool for stratigraphic correlation and for further refining the chronological framework of lake sediment sequences from Southern China. Further comparison of the HGY PSV records with the coeval European and North American counterparts confirms the existence of strong permanent magnetic flux lobes at the core-mantle boundary. The discrepancy in amplitude and out-phase pattern among the different regional records may be ascribed to the evolution of the magnetic flux lobes. [ABSTRACT FROM AUTHOR]