TY - JOUR
T1 - Characterizing magnetofossils from first-order reversal curve (FORC) central ridge signatures
AU - Heslop, David
AU - Roberts, Andrew P.
AU - Chang, Liao
PY - 2014/6
Y1 - 2014/6
N2 - The central ridge structure of a first-order reversal curve (FORC) distribution is indicative of uniaxial noninteracting single domain magnetic particles, which provides the opportunity to identify and characterize biogenic magnetic mineral remains (magnetofossils) in sediments. Recent studies have shown that magnetofossils are widespread in the geological record and that they carry useful environmental information and contribute to paleomagnetic recording, which makes it essential to quantify how these biogenic components contribute to the magnetic properties of sediments. We present results from six sedimentary sequences whose magnetic mineral assemblages contain a significant magnetofossil contribution. Using principal component analysis, we find that the central ridge properties exhibit both intra-sequnce and inter-sequence variability that may be ascribed to external environmental factors. While samples from individual sediment sequences tend to cluster together, there is a continuum of inter-sequence behavior that appears to be related to a variety of magnetofossil properties. We demonstrate the complexity of biogenic magnetic components in sedimentary environments, but also the power and potential of FORC central ridges for understanding magnetic mixtures and unraveling environmental information. Key Points First-order reversal curve central ridges carry magnetofossil information Central ridge form varies within and between different sediment sequences Central ridge magnetofossil characterization provides environmental information
AB - The central ridge structure of a first-order reversal curve (FORC) distribution is indicative of uniaxial noninteracting single domain magnetic particles, which provides the opportunity to identify and characterize biogenic magnetic mineral remains (magnetofossils) in sediments. Recent studies have shown that magnetofossils are widespread in the geological record and that they carry useful environmental information and contribute to paleomagnetic recording, which makes it essential to quantify how these biogenic components contribute to the magnetic properties of sediments. We present results from six sedimentary sequences whose magnetic mineral assemblages contain a significant magnetofossil contribution. Using principal component analysis, we find that the central ridge properties exhibit both intra-sequnce and inter-sequence variability that may be ascribed to external environmental factors. While samples from individual sediment sequences tend to cluster together, there is a continuum of inter-sequence behavior that appears to be related to a variety of magnetofossil properties. We demonstrate the complexity of biogenic magnetic components in sedimentary environments, but also the power and potential of FORC central ridges for understanding magnetic mixtures and unraveling environmental information. Key Points First-order reversal curve central ridges carry magnetofossil information Central ridge form varies within and between different sediment sequences Central ridge magnetofossil characterization provides environmental information
KW - First-order reversal curves
KW - magnetofossils
KW - sedimentary magnetism
UR - http://www.scopus.com/inward/record.url?scp=84905197849&partnerID=8YFLogxK
U2 - 10.1002/2014GC005291
DO - 10.1002/2014GC005291
M3 - Article
SN - 1525-2027
VL - 15
SP - 2170
EP - 2179
JO - Geochemistry, Geophysics, Geosystems
JF - Geochemistry, Geophysics, Geosystems
IS - 6
ER -