Rock Magnetic Signature of Heterogeneities Across an Intraplate Basal Contact: An Example From the Northern Apennines

Abstract

Plate boundaries at shallow depth are complex and highly deformed zones showing structures from both distributed and localized deformation (Collot et al., 2011;Sibson, 2013). Depending on the heterogeneity of the rock assemblage (i.e., competent vs. incompetent materials and/or clay contents) within the shear zone and the strain rates, shearing can be localized along discrete faults during seismic slip, while aseismic slip produces a scaly fabric associated with distributed deformation (Fagereng & Sibson, 2010;Kirkpatrick et al., 2015). Deciphering the stress and strain distribution across plate boundary shear zones is critical to understand the physical processes involved in the nucleation and behavior of megathrust faults.As magnetic minerals are sensitive to stress regime and fluid-rock interactions, the investigation of the magnetic properties of rocks can be an effective tool in studying faulting processes at intraplate shear zones (Yang et al., 2020). Anisotropy of magnetic susceptibility (AMS) provides insights into the preferred orientation of mineral grains and qualitative relationships between petrofabrics and deformation intensity (

Testing and Analysis Method of Low Remanence Materials for Magnetic Shielding Device

“…It is used to determine the saturation magnetization, coercivity and remanence of rock samples to analyze the influence of seismic slip-on rock magnetism. Robustelli et al [ 18 ] measured the Thermomagnetic susceptibility curves of the sample by heating the sample to 700 °C, and then cooling it to room temperature to measure the magnetic signature along interpolate sheet zones. Lund et al [ 19 ] tested the hysteresis loop of deep-sea sediment samples through the MicroMag cycle.…”

Strain Localization: Analog Modeling and Anisotropy of Magnetic Susceptibility

“…Therefore, as noted by Borradaile (1988) “magnetic fabrics should not be used for routine methods of ‘strain analysis’ without further study” as for example, composite fabrics of sedimentary, compaction and tectonic origin can result in distinct AMS due to lithology based differences in strain partitioning (Evans et al., 2003). All together this establishes the necessity to combine magnetic studies with microstructural, mineral chemistry and geochemical characterization as the relationship between fault or SZ kinematics and dynamics can be individual (Kusbach et al., 2019; Narloch et al., 2021; Robustelli Test & Zanella, 2021; Yang et al., 2020).…”

Coseismic Frictional Heating With Concomitant Hydrothermal Fluid Circulation Revealed by Rock Magnetic Properties of Fault Rocks From the Rupture of the 2008 Wenchuan Earthquake, China

“…Therefore, the magnetic properties of fault rocks could offer valuable insights into physical and chemical processes affecting fault rocks. The available rock magnetic studies on fault rocks from seismically active zones have demonstrated that magnetic properties of fault rocks could shed lights on strain geometry, seismic frictional heating, fluid infiltration, and so on (Chou et al., 2012a, 2012b, 2020; Ferré et al., 2012, 2014, 2017; Greve et al., 2020, 2021; D. Liu et al., 2014; Robustelli Test & Zanella, 2021; Yang et al., 2012, 2018, 2019; Yang, Yang, et al., 2016; L. Zhang et al., 2018; for a review, see Yang et al., 2020).…”

“…The available rock magnetic studies on fault rocks from seismically active zones have demonstrated that magnetic properties of fault rocks could shed lights on strain geometry, seismic frictional heating, fluid infiltration, and so on (Chou et al, 2012a(Chou et al, , 2012b(Chou et al, , 2020Ferré et al, 2012Ferré et al, , 2014Ferré et al, , 2017Greve et al, 2020Greve et al, , 2021D. Liu et al, 2014;Robustelli Test & Zanella, 2021;Yang et al, 2012Yang et al, , 2018Yang et al, , 2019L. Zhang et al, 2018; for a review, see Yang et al, 2020).…”