HR: 1340h
AN: GP23A-0030    [Abstracts]
TI: Magnetic Anomalies Between 35 N and 55 N in the North Atlantic: Identification and Implications
AU: * Luis, J
EM: jluis@ualg.pt
AF: J.F. Luis, University of Algarve FCMA Campus de Gambelas, Faro, 8000 Portugal
AU: Miranda, J M
EM: jmmiranda@fc.ul.pt
AF: J. M. Miranda, Centro de Geofisica da Universidade de Lisboa, Campo Grande, Ed C8., Lisboa, 1749-016 Portugal
AB: In this work we present a new approach to the detailed identification and interpretation of the magnetic isochrones 5, 6, 13, 18, 20, 22, 22, 23, 24, 25, 26, 28, 29, 30, 32, 33 and 33r on the Eurasian as well as on the American plate, between 55° N and 35° N in the North Atlantic. The identifications were based on a continuous reduction to the pole new technique. From the detailed reconstruction of magnetic isochrones and flow lines, we show that the East Azores Fracture Zone cannot be considered as homologous to the Pico Fracture Zone, implying that a significant amount of the Azores plateau was formed as an independent lithospheric band accreted to the Eurasian plate between the time of anomaly 22 (49 Ma) and ~5 (10 Ma). Based on magnetic anomalies and morphological constrains we reconstruct the previous configurations of the Azores plateau. In particular, we extend a previous study of the Mid-Atlantic Ridge (MAR) for the period 0-10 Ma to a wider time interval into a schematic evolution model for the Azores Triple Junction area. The new isochrones identifications and computation of Euler rotation poles have also implications in the movement of the ancient Iberia plate. Contrary to the currently accepted belief that its movement with respect to the Eurasia plate ended about the time of anomaly 6 (20 Ma), we found no evidences of any movement after the time of anomaly 18 (~38 Ma).
DE: 3005 Marine magnetics and paleomagnetics (1550)
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 3045 Seafloor morphology, geology, and geophysics
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005