Open AccessGeomagnetic excursion in the late Cretaceous
Author(s) -
Steiner Maureen B.
Publication year - 1983
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1983.tb03803.x
Subject(s) - excursion , geology , geomagnetic reversal , earth's magnetic field , paleontology , paleomagnetism , magnetostratigraphy , cretaceous , geomagnetic pole , sedimentary rock , seafloor spreading , geophysics , apparent polar wander , seismology , magnetic field , physics , quantum mechanics , political science , law
Summary. Two sedimentary cores from the western Pacific display a palaeo‐magnetic record of the late Cretaceous long normal interval and the boundary reversed interval corresponding to seafloor spreading anomalies 33–34. Near the young end of this reversed interval, a systematic excursion of inclinations is observed in both cores. Samples are very stable to both alternating field and thermal demagnetization. Blocking temperatures and Curie points suggest that the remanence is carried primarily by magnetite, but with an additional contribution from hematite. Approximate sedimentation rates derived from biostratigraphy suggest that the excursion had a duration of between 46 000 and 54 000yr and occurred about 236000–303000 yr before the succeeding polarity reversal. The excursion, thus, may represent an aborted geomagnetic field reversal.