Paleoseismology of the Mount Narryer fault zone, Western Australia: A multistrand intraplate fault system
| Autor: | Paul R. Bierman, Dan Clark, James V. Hengesh, Beau B. Whitney |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Fluvial Geology Paleoseismology Slip (materials science) Fault (geology) 010502 geochemistry & geophysics 01 natural sciences Tectonics Craton Intraplate earthquake Quaternary Seismology 0105 earth and related environmental sciences |
| Zdroj: | Geological Society of America Bulletin. 128:684-704 |
| ISSN: | 1943-2674 0016-7606 |
| DOI: | 10.1130/b31313.1 |
| Popis: | Our paleoseismological study of faults and fault-related folds comprising the Mount Narryer fault zone reveals a mid- to late Quaternary history of repeated morphogenic earthquakes that have influenced the planform and course of the Murchison, Roderick, and Sanford Rivers, Western Australia. The dominant style of deformation involves folding of near-surface sediments overlying discrete basement faults. Carbon-14, optically stimulated luminescence, and in situ–produced 10 Be constrain the timing of the events and late Quaternary slip rates associated with fault propagation folds in tectonically uplifted and deformed alluvial channel deposits. A flight of five inset fluvial terraces is preserved where the Murchison River flows across the Roderick River fault. These terraces, which we infer to be coseismic, are consistent with at least four late Quaternary seismic events on the order of moment magnitude (M w ) 7.1 within the last ~240 k.y. Secondary shears expressed on the folds indicate a component of dextral strike-slip displacement. Quaternary slip rates on the underlying faults range from 0.01 to 0.07 mm yr –1 , with a total slip rate for the zone between 0.04 and 0.11 mm yr –1 . These rates are intermediate to those in the adjacent Mesozoic basin (>0.1 mm yr –1 ) and Precambrian craton ( –1 ) and so provide insight into how tectonic strain is partitioned and transferred across a craton margin. |
| Databáze: | OpenAIRE |
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