Artículo

New contributions to the Early Pliocene geomagnetic field strength: Case study of southern Caucasus volcanics

Goguitchaichvili, Avto; Alva Valdivia, Luis; Morales, Juan; Caballero, Cecilia; González, José Antonio

Instituto de Geofísica, UNAM, publicado en Geofísica Internacional, y cosechado de Revistas UNAM

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Procedencia del contenido

Entidad o dependencia
Instituto de Geofísica, UNAM
Revista
Repositorio
Contacto
Revistas UNAM. Dirección General de Publicaciones y Fomento Editorial, UNAM en revistas@unam.mx

Cita

Goguitchaichvili, Avto, et al. (2000). New contributions to the Early Pliocene geomagnetic field strength: Case study of southern Caucasus volcanics. Geofísica Internacional; Vol. 39 No. 3, 2000. Recuperado de https://repositorio.unam.mx/contenidos/42598

Descripción del recurso

Autor(es)
Goguitchaichvili, Avto; Alva Valdivia, Luis; Morales, Juan; Caballero, Cecilia; González, José Antonio
Tipo
Artículo de Investigación
Área del conocimiento
Físico Matemáticas y Ciencias de la Tierra
Título
New contributions to the Early Pliocene geomagnetic field strength: Case study of southern Caucasus volcanics
Fecha
2012-05-08
Resumen
We carried out a Thellier paleointensity study on a ~ 3.8 My Pliocene lava flow succession from Georgia (southern Caucasus).Previous paleomagnetic studies on this succession revealed that eight consecutive lava flows record a reverse polarity direction atthe base of the section followed by a thick normal polarity zone of eighteen consecutive flows. 27 samples from 9 flows from bothpolarity zones were preselected for paleointensity experiments because of their low magnetic viscosity index, stable remanentmagnetization, reversible thermomagnetic curves and minor fraction of grains with a multidomain magnetic structure. Altogether,13 samples from 6 different cooling units yielded reliable paleointensity estimates with flow-mean virtual dipole moments rangingfrom 5.8 to 7.6*1022 Am2. Our results, although not numerous, are of high technical quality and comparable to other paleointensitydata recently obtained on younger lava flows. The NRM fractions used for paleointensity determination range from 28 to 65% andthe quality factors varies between 4.7 and 19.4, being normally greater than 5. The mean virtual dipole moment (VDM) obtainedin this study is slightly lower than the present day geomagnetic field strength but it is in accordance with the mean early Plioceneworldwide VDM. The results are also similar to those recently reported for the late Miocene (8-10 My), which may indicate thatgeomagnetic field strength was stable and relatively high from about 10 to 4 My. More data are needed to better understand thetransition mode between Mesozoic low and the present high geomagnetic field.
Tema
Paleomagnetismo; paleointensidad; método Thellier; Cáucaso; Plioceno.; Paleomagnetism; paleointensity; Thellier method; Caucasus; Pliocene.
Idioma
spa
ISSN
0016-7169

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