Paleosecular variation recorded by Quaternary lava flows from Guadeloupe Island.
Sci Rep
; 8(1): 10147, 2018 07 05.
Article
em En
| MEDLINE
| ID: mdl-29976984
ABSTRACT
Paleomagnetic directional data were obtained from fourteen 0 to 2 Ma old lava flows at Basse-Terre Island (Guadeloupe, French West Indies). Five reversed polarity flows are consistent with their Matuyama age between 1.6-1.5 Ma and 875-790 ka while the ages of the other nine normal polarity units tie them to the Olduvai subchron and the Brunhes Chron. These directions have been combined with previous results obtained from Basse-Terre Island. The overall mean direction (D = -1.2°, I = 31.4°, α95 = 3.3°) obtained from the 39 non-transitional flows from Basse-Terre Island is indistinguishable from the expected geocentric axial dipole value (D = 0°, I = 29.8°). The dispersion measured from the angular standard deviation of the Virtual Geomagnetic Poles (VGPs) was found to be close to, but smaller than the predictions of geomagnetic models. Together with further directions from the nearby Martinique Island, the 45 directions obtained within the Brunhes chron provide the most robust estimate of the statistical distribution of paleosecular variation (PSV) at this latitude. The sequence of directions shows episodes of high amplitude secular variation that are coeval with several geomagnetic events including the last reversal documented by five transitional directions. Finally, three lava flows have recorded a transitional behavior which could be link to two excursions, the Laguna del Sello (at ~340 ka) and the Pringle Falls (at ~210 ka) events.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
Guadalupe
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
França