HR: 0800h
AN: T41A-0383    [Abstracts]
TI: Structural and Stratigraphic Evolution of the Corinth Rift: Providing Constraints for Early Syn- Rift Deformation Modeling
AU: * Bell, R E
EM: reb1@noc.soton.ac.uk
AF: National Oceanography Centre, Southampton, University of Southampton Waterfront Campus European Way, Southampton, SO14 3ZH, United Kingdom
AU: McNeill, L
EM: lcmn@noc.soton.ac.uk
AF: National Oceanography Centre, Southampton, University of Southampton Waterfront Campus European Way, Southampton, SO14 3ZH, United Kingdom
AU: Bull, J
EM: jmb1@noc.soton.ac.uk
AF: National Oceanography Centre, Southampton, University of Southampton Waterfront Campus European Way, Southampton, SO14 3ZH, United Kingdom
AU: Henstock, T
EM: then@noc.soton.ac.uk
AF: National Oceanography Centre, Southampton, University of Southampton Waterfront Campus European Way, Southampton, SO14 3ZH, United Kingdom
AU: Stefatos, A
EM: ast@rocksource.com
AF: Laboratory of Marine Geology and Physical Oceanography, Department of Geology, University of Patras, Patras, 265 00, Greece
AB: Observations of the style of extension and strain distribution during the initiation and early stages of rifting can be used to test predictions of syn-rift subsidence and stratigraphy generated by numerical rift models. Plausible syn- rift deformation models must consider: the role of pure shear vs. simple shear; the nature and distribution of border faults; the duration and rate of slip on these faults; and the activation and propagation of the rift system. The young, <5 Ma Gulf of Corinth rift is an ideal place to study these syn-rift processes. The EW trending rift is actively extending at a rate of up to ~15 mm/yr in a NS direction, overprinting a relatively simple pre-rift geology. Using a combination of new high resolution MCS and swath bathymetry data in the western Gulf, together with archived and published datasets we produce a comprehensive fault map for the Gulf of Corinth rift system and document spatial and temporal changes to its basin geometry. In addition to the well-studied N- dipping faults on the southern margin we observe a system of offshore S-dipping faults that define the northern boundary of the major sediment depocenter. The switching dominance of these fault systems through time and space is responsible for the complex basin geometry of the Corinth rift. A major apparently basin-wide unconformity, with an estimated age of ~0.4 Ma separates syn-rift stratigraphy into two main units. In the western part of the Gulf, pre ~0.4 Ma, the geometry of sediment packages indicates that rift geometry was controlled by S-dipping faults on the northern margin. Toward the center and eastern part of the rift, the activity of N- and S-dipping faults was more equivalent, producing a symmetrical graben morphology. Post ~0.4 Ma stratigraphy tilts and thickens southward in the central and eastern Gulf with N-dipping faults having structural control at this time. In the western Gulf S-dipping faults retain overall control and horizons dip north. Sequence stratigraphic interpretation in some parts of the rift has enabled slip rate estimation for major fault systems. Multiple fault dislocation modeling has been used in an attempt to recreate basement structure using the fault slip rate estimates as derived from stratigraphic analysis and uplifted marine terraces. The complex spatially and temporally varying style of syn-rift extension in the Corinth rift must be considered in future rift models that attempt to accurately recreate the mechanical, thermal and sedimentary histories of extensional basins.
DE: 8004 Dynamics and mechanics of faulting (8118)
DE: 8107 Continental neotectonics (8002)
DE: 8109 Continental tectonics: extensional (0905)
DE: 8169 Sedimentary basin processes
DE: 8175 Tectonics and landscape evolution
SC: Tectonophysics [T]
MN: 2007 Fall Meeting