Abstract
Izu-Bonin forearc tectonics subsequent to Pacific Plate subduction initiation; resolving a 15 Ma hiatus enigma
American Geophysical Union Fall Meeting, Vol.2019
American Geophysical Union 2019 fall meeting
12/2019
Abstract
International Ocean Discovery Program Expedition 352 sites U1439-U1442 obtained sedimentary-volcanoclastic sequences that allow the reconstruction of the Izu-Bonin forearc tectonic evolution. The oldest recorded biostratigraphic ages of the sediment cover (late Eocene to early Oligocene) imply a hiatus of up to 15 million years between the formation of the igneous basement around 52 to 47 Ma and the onset of pelagic sedimentation. At the forearc upslope sites (U1439, U1442) extension resulted in the formation of asymmetric, fault-bounded basins. Displacement along confining normal faults is in the range of 310 meters, resulting in stretching by approximately 16%-19% at strain rates in the range of 1.58 X 10 (super -16) to 4.62 X 10 (super -16) . Downslope site U1441 is characterized by symmetric graben structures bound by conjugate normal faults. Displacement along these faults is approximately 660 m to 770 m, resulting in extension in the range of approximately 4 at strain rates of 9.66 X 10 (super -15) to 3.31 X 10 (super -15) . Incipient roll-back of the Pacific Plate approximately 15 Ma after igneous basement
Details
- Title: Subtitle
- Izu-Bonin forearc tectonics subsequent to Pacific Plate subduction initiation; resolving a 15 Ma hiatus enigma
- Creators
- Walter Kurz - University of GrazPeter MicheuzGail L ChristesonMark K ReaganJohn W ShervaisSteffen KutterolfAlastair RobertsonKurt KrennKatsuyoshi MichibayashiDennis Quandt
- Resource Type
- Abstract
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2019
- Conference
- American Geophysical Union 2019 fall meeting
- Publisher
- American Geophysical Union
- Alternative title
- AGU 2019 fall meeting
- Language
- English
- Date published
- 12/2019
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984230121102771
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