The Relationships Between Regional Quaternary Uplift, Deformation Across Active Normal Faults, and Historical Seismicity in the Upper Plate of Subduction Zones: The Capo D'Orlando Fault, NE Sicily. Issue 5 (5th May 2018)

• Record Type: Journal Article
• Authors: Meschis, M.; Roberts, G. P.; Robertson, J.; Briant, R. M.
• Is Part Of: Tectonics. Volume 37:Issue 5(2018)
• Page Start: 1231
• Page End: 1255
• Publication Date: 2018-05-05
• Subjects: Quaternary -- palaeoshorelines -- uplift‐rate -- normal‐faulting -- synchronous correlation method -- sea‐level changes; Geology, Structural -- Periodicals; 551.8
• DOI: 10.1029/2017TC004705
• Languages: English
• ISSNs: 0278-7407

Abstract

Abstract: In order to investigate the deformation within the upper plate of the Calabrian subduction zone, we have mapped and modeled a sequence of Late Quaternary paleoshorelines tectonically deformed by the Capo D'Orlando normal fault, NE Sicily, which forms part of the actively deforming Calabrian Arc. In addition to the 1908 Messina Strait earthquake ( M w 7.1), this region has experienced damaging earthquakes, possibly on the Capo D'Orlando Fault; however, it is not considered by some to be a potential seismogenic source. Uplifted Quaternary paleoshorelines are preserved on the hangingwall of the Capo D'Orlando Fault, indicating that hangingwall subsidence is counteracted by regional uplift, likely because of deformation associated with subduction/collision. We attempt to constrain the relationship between regional uplift, crustal extensional processes, and historical seismicity, and we quantify both the normal and regional deformation signals. We report uplift variations along the strike of the fault and use a synchronous correlation technique to assign ages to paleoshorelines, facilitating calculation of uplift rates and the fault throw rate. Uplift rates in the hangingwall increase from 0.4 mm/year in the center of the fault to 0.89 mm/year beyond its SW fault tip, suggesting 0.5 mm/year of fault‐related subsidence, which implies a throw rate of 0.63 ± 0.02 mm/year, and significant seismic hazard. Overall, we emphasize that upper plate extension and related vertical motions complicate the process of deriving information on the subduction/collision process, such as coupling and slip distribution on the subduction interface, parameters that are commonly inferred for other subduction zones without considering upper plate deformation. Key Points: Late Quaternary paleoshorelines have been tectonically deformed by the Capo D'Orlando Fault (NE Sicily), implying that this fault is active Refining paleoshoreline ages unveils a constant uplift rate through time, implying new fault slip rate and Earthquake Recurrence Interval A worldwide review of slip distribution calculations on subduction interfaces is suggested considering upper plate crustal deformation