Open AccessEvidence for a variable paleomagnetic lock‐in depth in the Holocene sequence from the Salerno Gulf (Italy): Implications for “high‐resolution” paleomagnetic dating
Author(s) -
Sagnotti Leonardo,
Budillon Francesca,
DinarèsTurell Jaume,
Iorio Marina,
Macrì Patrizia
Publication year - 2005
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2005gc001043
Subject(s) - paleomagnetism , geology , paleontology , sedimentary rock , magnetostratigraphy , earth's magnetic field , sequence (biology) , rock magnetism , radiocarbon dating , geophysics , remanence , magnetization , magnetic field , biology , genetics , physics , quantum mechanics
We report on a paleomagnetic and rock magnetic study of two adjacent marine gravity cores from the Salerno Gulf (Italy), with measurements carried out on u‐channel samples at 1‐cm spacing. The cores recover a sedimentary sequence spanning, in the overlapping part, the last ∼6000 years and include a thick (∼1 m) pumice layer produced during the Somma‐Vesuvius eruption of 79 A.D. Rock magnetic and lithostratigraphic data provide several tie‐points for a detailed correlation between the two cores. Paleomagnetic data allow the determination of a well‐defined characteristic remanent magnetization, with very similar stratigraphic trends and distinct features that can also be unambiguously correlated between the cores. However, the comparison of the various data sets points out that the paleomagnetic lock‐in depth in the two adjacent cores varies through the stratigraphic succession. We discuss the implication of such results for assessing the potential of high‐resolution paleomagnetic studies in dating sedimentary sequences on the basis of paleosecular variation of the geomagnetic field. In the studied case, the relative difference in the lock‐in depth in the two cores causes “spreading” of the assigned paleomagnetic ages at a century scale.