HR: 0800h
AN: GP11D-0872    [Abstracts]
TI: The Time-Averaged Field at the Equator: Results from Ecuador
AU: * opdyke, N D
EM: drno@ufl.edu
AF: Department of Geological Sciences, University of Florida, 241 Williamson Hall, P.O. Box 112120, Gainesville, FL 32611-2120 United States
AU: Hall, M L
EM: volcan\_pete@yahoo.com
AF: Department of Geophysics, Escuela Politecnica Nacional, A.P. 17-01, Quito, 2759 Ecuador
AU: Mejia, V
EM: vmejia@ufl.edu
AF: Department of Geological Sciences, University of Florida, 241 Williamson Hall, P.O. Box 112120, Gainesville, FL 32611-2120 United States
AU: Huang, K
EM: knhuang@geology.ufl.edu
AF: Department of Geological Sciences, University of Florida, 241 Williamson Hall, P.O. Box 112120, Gainesville, FL 32611-2120 United States
AU: Foster, D A
EM: dafoster@ufl.edu
AF: Department of Geological Sciences, University of Florida, 241 Williamson Hall, P.O. Box 112120, Gainesville, FL 32611-2120 United States
AB: Seventy sites were collected from Pliocene to recent lavas in Ecuador at latitudes of less than 1\deg south. Lighting affected many of the sites sampled and the final data set consisted of 49 sites with \alpha$_{95}$ of 10\deg or less. Nineteen flows yielded normal (Dec = 355.8\deg, Inc = -5.8\deg,\alpha$_{95}$ = 7.1\deg) and 29 reverse (Dec = 182.5\deg, Inc = 5.7\deg,\alpha$_{95}$ = 4.9\deg) directions of magnetization. These sites pass a reversal test at a high level. The combined data give a direction of Dec = 359.8\deg, Inc -5.8\deg,\alpha$_{95}$ = 4.1\deg, which is just significantly different from the GAD field. These results are however what is expected if a 5% quadrupole component is added to the dipole field. The dispersion of the selected site mean directions is 13.2\deg which is not significantly higher than the value expected from Model "G".
DE: 1522 Paleomagnetic secular variation
DE: 1560 Time variations--secular and long term
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting