2026-07-24T16:34:55Zhttps://riubu.ubu.es/oai/requestoai:riubu.ubu.es:10259/61082022-11-29T08:42:41Zcom_10259.4_2560com_10259_5086com_10259_2604col_10259.4_2561
Weak palaeointensity results over a Pliocene volcanic sequence from Lesser Caucasus (Georgia): transitional record or time averaged field?
Sánchez Moreno, Elisa María
Calvo Rathert, Manuel
Goguitchaichvili, Avto
Tauxe, Lisa .
Vashakidze, George T.
Lebedev, Vladimir A.
Palaeointensity
Magnetic field variations through time
Palaeomagnetism
A palaeointensity study has been carried out on a Pliocene sequence of 20 consecutive lava
flows where previous directional results seem to reflect anomalous behaviour of the Earth’s
magnetic field (EMF), which can be explained by a polarity transition record or non-averaged
palaeosecular variation or both. Here, we perform a total of 55 palaeointensity determinations
using the original Thellier–Thellier (TT) method and 100 with the IZZI method.We assess the
performance of our selection criteria using a set of strict threshold values applied to a set of
test data whose TRMs were acquired in known fields. Absolute palaeointensity determinations
that passed our selection criteria were obtained on four specimens with the TT method and on
41 specimens with the IZZI method. Application of reliability criteria at a site level yielded
palaeointensity results in 8 of 20 studied lava flows. We obtained median values of VADM
between 28.9 and 45.6 ZAm2 for the reverse polarity lower Apnia section, while the normal
polarity upper section displayed a single value of 54.6 ZAm2. The low palaeointensity values
before a transitional direction lava flow and the higher value after it, suggest the common
behaviour at the start of a polarity reversal and the recovery after it. However, an isolated
record of a stable EMF, where the intensity is lower than the current for the same location
(83.7 ZAm2), cannot be discarded. Consequently, this interpretation would support a weak
time-averaged field.
2021-11-05
2021-11-05
2020-03
info:eu-repo/semantics/article
1365-246X
http://hdl.handle.net/10259/6108
10.1093/gji/ggz533
eng
Geophysical Journal International. V. 220, n. 3, p. 1604–1618
https://doi.org/10.1093/gji/ggz533
info:eu-repo/grantAgreement/MINECO//CGL2012-32149/ES/VARIACION DE LA PALEOINTENSIDAD ABSOLUTA DEL CAMPO MAGNETICO TERRESTRE REGISTRADA EN ROCAS VOLCANICAS: MOMENTO DIPOLAR, TRANSICIONES DE POLARIDAD Y SUPERCRONES
info:eu-repo/grantAgreement/Junta de Castilla y León//BU066U16//Estudio arqueomagnéticos y de propiedades magnéticas en registros de fuegos antrópicos prehistóricos. Aplicaciones a la arqueología
info:eu-repo/grantAgreement/MINECO//BES-2013-064060
info:eu-repo/grantAgreement/NSF//EAR1345003
info:eu-repo/semantics/openAccess
Oxford University Press