Open AccessPalaeomagnetic record in Late Pleistocene and Holocene dry lake deposits at Tlapacoya, Mexico
Author(s) -
Liddicoat J. C.,
Coe R. S.,
Lambert P. W.,
Valastro S.
Publication year - 1979
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.1979.tb06772.x
Subject(s) - geology , excursion , earth's magnetic field , paleomagnetism , pleistocene , paleontology , shore , holocene , polarity (international relations) , quaternary , geophysics , oceanography , magnetic field , physics , genetics , quantum mechanics , biology , political science , law , cell
Summary. A palaeomagnetic investigation of Carbon‐14‐dated marsh and near‐shore lacustrine sediments deposited between about 25000–5000 yr bp at Tlapacoya, Mexico, reveals normal polarity of the geomagnetic field in all samples measured. At one site, anomalous palaeomagnetic directions in a mud unit dated about 14500 yr bp raised the possibility of a geomagnetic excursion, but subsequent work at six additional sites in the unit revealed no abnormal directions. Thus the anomalous directions are most likely not a true reflection of geomagnetic field behaviour, although no specific alternative explanation is entirely convincing. The preliminary Tlapacoya data of anomalous directions have been cited by others as positive evidence for an excursion. We strongly recommend it no longer be considered as such.