Asymmetric Brittle Deformation at the Pāpaku Fault, Hikurangi Subduction Margin, NZ, IODP Expedition 375
| Autor: | Demian M. Saffer, Maomao Wang, Katerina Petronotis, Srisharan Shreedharan, Julia K. Morgan, Leah J. LeVay, Francesca Meneghini, David D. McNamara, Heather M. Savage, Laura M. Wallace, Philip M. Barnes, Ake Fagereng |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Subduction Hikurangi Margin subduction zone Deformation (meteorology) Fault (geology) 010502 geochemistry & geophysics fault damage fracture density Hikurangi margin 01 natural sciences Geophysics Brittleness Geochemistry and Petrology Margin (machine learning) 14. Life underwater Seismology Geology 0105 earth and related environmental sciences |
| Zdroj: | Geochemistry, Geophysics, Geosystems |
| ISSN: | 1525-2027 |
| Popis: | Quantifying fault damage zones provides a window into stress distribution and rheology around faults. International Ocean Discovery Program (IODP) Expeditions 372/375 drilled an active thrust splay fault within the Hikurangi subduction margin. The fault, which is hosted in Pleistocene clastic sediments, is surrounded by brittle fractures and faults as well as ductile deformation features. We find that fracture density in the damage zone enveloping the fault is asymmetric, with the hanging wall showing greater overall fracture density and at greater distances from the fault than the footwall. Furthermore, the peak in fracture density occurs within an area of mesoscale folding and localized slip in the hanging wall rather than adjacent to the main fault zone. We attribute the asymmetry in damage to disparate deformation histories between the hanging wall and footwall, greater ductile deformation within the footwall, and/or dynamic stress asymmetry around a propagating rupture. Damage asymmetry is common at shallow depths in subduction zones and influences the mechanical and hydrological properties of the fault, such as channelized fluid flow and fault stability. Finally, we demonstrate that subduction zone faults show similar damage-displacement scaling as continental faults. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|