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Pseudopaleosecular variation due to remanence anisotropy in a pyroclastic flow succession
Author(s) -
Gattacceca Jerome,
Rochette Pierre
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl014697
Subject(s) - paleomagnetism , thermoremanent magnetization , geology , remanence , anisotropy , pyroclastic rock , rock magnetism , seismology , geophysics , mineralogy , magnetization , volcano , physics , magnetic field , quantum mechanics
In order to check the reliability of a paleosecular variation record in a sequence of pyroclastic rocks (Miocene, Sardinia), we measured various types of anisotropy: magnetic susceptibility (AMS), anhysteretic remanent magnetization (AARM) and thermoremanent magnetization (ATRM). The main magnetic carrier is pseudo‐single domain titanomagnetite. No general relation appears between the degrees of AMS and AARM, while the degrees of AARM and ATRM are almost identical. Measuring the AARM thus provides a fast and reliable method to correct paleomagnetic deviation in volcanic rocks. Once corrected for anisotropy deviation the apparent scatter of the paleomagnetic directions, mostly on inclination, is drastically reduced.