HR: 1330h
AN: GP13B-09    [Abstracts]
TI: A Sedimentary Record of the Lower Jaramillo Transition Zone
AU: * Tait, J A
EM: jenny@geophysik.uni-muenchen.de
AF: Department of Earth and Environmental Sciences, Ludwig-Maximilians Universit„t, Theresienstrasse 41, Munich, 80333 Germany
AU: Gurary, G Z
EM: palmag@online.ru
AF: Geological Institute, Russian Academy of Sciences, Pyzhevsky per. 7, Moscow, 109017 Russian Federation
AU: Trubikhin, V
EM: palmag@online.ru
AF: Geological Institute, Russian Academy of Sciences, Pyzhevsky per. 7, Moscow, 109017 Russian Federation
AU: Garbuzenko, A
EM: palmag@online.ru
AF: Geological Institute, Russian Academy of Sciences, Pyzhevsky per. 7, Moscow, 109017 Russian Federation
AU: Iglesia-Llanos, P
EM: p_iglesia@yahoo.es
AF: Geological Institute, Russian Academy of Sciences, Pyzhevsky per. 7, Moscow, 109017 Russian Federation
AU: Ataev, N M
EM: irina@cpart.org
AF: Turkemgeologiya, Magtymguly Cayloly 81, Ashgabad, Turkmenistan
AB: Biostratigraphically dated Apsheronian sediments were sampled from two parallel sections near Adjidhere, NW Turkmenistan. Demagnetisation experiments reveal well defined normal and reversed magnetisations carried by magnetite and haematite. The lower/upper parts of the sections correspond to the Matuyama/Jaramillo chrons, and corresponding mean directions coincide with the local dipole field. The central part of the composite section reveals a remarkable and complex record of the transitional field, a significant feature of which is the clustering of VGPs in the S Atlantic, between the S Pole and southern S America. This feature predominates in the earlier phases of the transition and corresponds to the cluster patch previously identified from volcanic records of different transition zones. Another striking feature is the repetition of excursion patterns, with the VGP paths repeatedly moving along preferred paths, before finally reversing in the central part of the profile. Initialy, the field instability is predominantly reversed in character. After the reversal, however, the record shows instability from a predominantly normal condition. These data will be presented and discussed
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
DE: 1535 Reversals (process, timescale, magnetostratigraphy)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2005 Joint Assembly