Open AccessGeomagnetic Polarity Reversals in a Late Tertiary Lava Sequence from the Akaroa Volcano, New Zealand
Author(s) -
Evans A. Ll.
Publication year - 1970
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.1970.tb01774.x
Subject(s) - lava , polarity (international relations) , geology , earth's magnetic field , volcano , geomagnetic reversal , geophysics , magnetic anomaly , sequence (biology) , anomaly (physics) , geomagnetic pole , peninsula , paleomagnetism , geodesy , seismology , paleontology , magnetic field , physics , chemistry , condensed matter physics , geography , biochemistry , archaeology , quantum mechanics , cell
Summary Palaeomagnetic measurements and potassium‐argon age determinations have been performed on two sequences of lava flows from the Banks Peninsula, New Zealand. Flows from the Stoddart Formation are entirely of reversed polarity and were formed rapidly at 5.85±0.04 My ago. The Akaroa sequence, extruded over a time interval from 9.1 to 8.4 My ago, records seven reversals of the Earth's magnetic field. The geomagnetic polarity time scale constructed from these results agrees well with the time scales postulated from the interpretation of magnetic anomaly patterns over mid‐ocean ridges. The age of the polarity reversal terminating the normal period associated with Anomaly 5 is 8.67±0.13 My.