HR: 0830h
AN: T51D-0189    [PDF]
TI: A Quantitative Analysis of Rift Processes in the Northern North Sea and Central Greece.
AU: * Bryon, J G
EM: bryon@esc.cam.ac.uk
AF: Bullard Laboratories, Madingley Rise, Madingley Road, Cambridge, CB3 0EZ United Kingdom
AU: White, N J
EM: nwhite@esc.cam.ac.uk
AF: Bullard Laboratories, Madingley Rise, Madingley Road, Cambridge, CB3 0EZ United Kingdom
AB: Actively extending sedimentary basins provide a snapshot of the way in which basins evolve. Our observations from such regions are temporally limited: we have little understanding of the long-term processes involved but an excellent understanding of the short-term motions (10$^{0}$-10$^{2}$ years). The converse is true of tectonically dead basins where the deformation has ceased and only the end product can be observed. Studies of active basin formation in central Greece have provided a quantitative understanding of the kinematics of extensional tectonics. The use of GPS, SAR interferometry and geomorphological analysis has constrained the rate of extension and fault kinematics and geometries. Central Greece has often been cited as a present-day analogue for formation of the now inactive East Shetland Basin (ESB) in the northern North Sea. A large 3D seismic dataset has been compiled giving complete coverage of the ESB, a region comparable in size to central Greece ($\sim$10,000 km$^{2}$). A quantitative comparison between Greece and the ESB will close the gap in knowledge between short-term and long-term motions. Whilst the two regions have many features in common, such as tilted fault blocks, fault segments of comparable length and similar fault geometries, there are also important differences. For example, one difference between Greece and the northern North Sea is the rate of extension. The North Sea had a peak strain rate that was an order of magnitude slower than the rate at which Greece is currently extending across the gulfs of Corinth and Evia. Another difference is that the distance between large active faults in Greece appears to be significantly longer than in the ESB. A specific example of this difference in scale is the Tern-Eider ridge, which is a horst block in the ESB that appears superficially similar to the island of Evia in Greece. However, the rigid island of Evia is significantly wider than the Tern-Eider ridge. A link between this inter-fault distance and strain rate is currently being investigated, along with an evaluation of elastic thickness in the areas concerned.
DE: 8010 Fractures and faults
DE: 8105 Continental margins and sedimentary basins
DE: 8107 Continental neotectonics
DE: 8109 Continental tectonics--extensional (0905)
SC: Tectonophysics [T]
MN: 2003 Fall Meeting