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A Geophysical Investigation Of The Gulf Of Corinth, Greece
| Content Provider | Semantic Scholar |
|---|---|
| Author | Weiss, Jonathan R. |
| Copyright Year | 2004 |
| Abstract | This study provides insight into the process of continental extension and rift basin formation by focusing on the structural geometry, faulting, and sedimentation in the Gulf of Corinth, Greece. The Gulf of Corinth, opening at a rate of 11-16 mm/yr, is the second fastest opening rift on the earth today and has been the locus of 11 Mb=5.0-6.1 earthquakes in the past 30 years, making it an important location for understanding processes related to rapid continental extension. I processed and interpreted a grid of -50 multi-channel seismic profiles and multibeam bathymetry collected in the Gulf aboard RN Maurice Ewing in the summer of 2001, the first comprehensive MCS investigation of the Gulf of Corinth. Large-offset, intermediate angle (dips of 30°-50°), right-stepping en echelon to overlapping, north-dipping normal faults bound the southern Gulf margin. The faults are listric and become low-angle (dips of 19-33°) near the base of the synrift section and within the basement but are not imaged extending to depths greater than -4 km. High angle (dips >50°) normal faults occur within the central basin and on its northern margin. Some of these faults controlled the early rift basin evolution and, in the west, some remain dominant structures today. The synrift sediment thickness in the Gulf is no greater than 2.5 km, half that predicted by thick elastic plate models of rift flank uplift and footwall subsidence, which take into account sedimentation rates and changing marine levels [e.g. Armijo et al., 1996]. The thickest sediment accumulations occur near iv the center, and on the hanging walls, of the major faults. Strata typically exhibit normal drag against the faults. Additional thick sediments occur within hanging wall grabens on the crest of roll over anticlines and in the central basin. Sediment delivery to the modern depocenter at 850-880 mbsl occurs from all sides: the low-relief northern margin, the sUbsidiary Gulf of Antikyra in the east, the high-relief southern margin, and by axial channels from the shallower and narrower western basin, but primarily from the latter two. Most rivers that originate many kilometers south of the coastline on the Peloponnesus Peninsula predate the current border fault configuration, maintain their courses, and incise deep canyons on the uplifted footwalls of the active border faults and on the submarine slope. However, Heliki fault footwall uplift redirects flow of the Kratis River towards the ramp between the en echelon Heliki and Derveni faults, which do not overlap. Stratigraphic patterns on the hanging wall of the eastern tip of the Heliki fault indicate lateral and vertical fault propagation similar to subaerial faults in the Suez rift [Gawthorpe et al., 1997]. In general, processes related to faulting and sedimentation in the Gulf of Corinth are not dissimilar from other rift basins despite the unique forearc setting of the Gulf. The MCS data do not directly image lowor high-angle faults penetrating the seismogenic zone at 6-15-km-depth beneath the Gulf. However, the observations from the Gulf of Corinth presented here contribute to our overall understanding of rift basin formation and emphasize that intermediate to low angle, listric normal faults are active in the Gulf and provide further evidence that low-angle faults are important structures that accommodate rapid extension. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.soest.hawaii.edu/gg/resources/theses/MS_2004_Weiss.pdf |
| Alternate Webpage(s) | http://scholarspace.manoa.hawaii.edu/bitstream/10125/10469/1/uhm_ms_3946_r.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
