Rapid subsidence and sedimentation from oblique slip near a bend on the North Anatolian transform fault in the Marmara Sea, Turkey
- Leonardo Seeber1,
- Marie-Helene Cormier1,
- Cecilia McHugh1,
- Omer Emre2,
- Alina Polonia3 and
- Christopher Sorlien4
- 1Queens College, C.U.N.Y., 65-30 Kissena Boulevard., Flushing, New York 11367, USA and Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA
- 2General Directorate of Mineral Research and Exploration (MTA), Ankara, Turkey
- 3Istituto Geologia Marina, Comitato Nazionale Ricerche, Via Gobetti 101, Bologna 40129 Italy
- 4Institute for Crustal Studies, University of California–Santa Barbara, Santa Barbara, California 93106, USA
Abstract
Several basins are developing near bends on strands of the North Anatolian transform fault in northwest Turkey. Oblique slip on these faults, rather than strain partitioning, accounts for trans tension and subsidence. These basins are asymmetric, and tilt and subside most rapidly at their narrow ends near the bends. The turbidite surface marking the floor of the Cinarcik Basin (eastern Marmara Sea) was mostly abandoned at a sudden drop in sedimentation, which was likely coincident with the 14 ka lake-sea transition, and is now a warped reference surface from which we can measure strain and sedimentation. Subsidence and tilt are rapid, but do not require late Quaternary changes in regime. They are linked to transcurrent motion by slip parallel to an oblique bend on the North Anatolian fault and suggest tsunamogenic vertical motion in large Marmara Sea earthquakes.
Footnotes
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- Accepted 7 June 2006.
- Received 9 January 2006.
- Revision received 19 May 2006.
- The Geological Society of America, Inc.
