Biomarkers heat up during earthquakes: New evidence of seismic slip in the rock record

Fluid-rock interaction recorded in black fault rocks in the Kodiak accretionary complex, Alaska

“…This temperature is at least 100°C higher than the approximately 250°C estimated background temperature of the Pasagshak Point Thrust determined by vitrinite reflectance (Rowe et al 2011) and is only achievable under conditions of coseismic frictional heating. High temperatures recorded in the BFR are consistent with recent results of biomarker thermal maturity (Savage et al 2014). In contrast to BFR, foliated and non-foliated cataclasites exhibit no high-temperature signals.…”

“…Conversely, grain-supported BFRs and clast-bearing BFRs are considered to be reworked pseudotachylytes that have mixed with surrounding cataclasites, respectively (Meneghini et al 2010). BFRs show the greatest biomarker thermal maturity, whereas that of the cataclasites decreases with distance from the BFRs (Savage et al 2014). BFRs, foliated cataclasites, and non-foliated cataclasites exhibit mutually crosscutting relationships (Additional file 1: Figure S1e) and represent repeated deformations with different strain rates, which may be related to seismic cycles (Rowe et al 2011).…”

Seismic heating signatures in the Japan Trench subduction plate-boundary fault zone: evidence from a preliminary rock magnetic ‘geothermometer’

“…Vitrinite reflectance, fission-track, and biomarkers appear particularly promising (d'Alessio et al 2003;Fulton & Harris 2012;Savage et al 2014). Sometimes an approach requires a specific lithology to be applicable: vitrinite reflectance and biomarkers require sediments that contain certain types of organic matter, and fission track requires the presence of uranium-rich inclusions in certain minerals.…”

“…Sakaguchi et al 2011), and biomarker thermal maturity (e.g. Savage et al 2014). The applicability of each of these methods is dependent on the lithology of the fault zone, and temperatures that are identifiable with most of these techniques are rather low, that is <250-300…”

Generation of billow-like wavy folds by fluidization at high temperature in Nojima fault gouge: microscopic and rock magnetic perspectives

“…In order to identify seismic slip zones and constrain the temperature rise in fault gouge during seismic slip, electron spin resonance (ESR) (Fukuchi 2003(Fukuchi , 2012, biomarkers (Savage et al 2014), vitrinite reflectance (Maekawa et al 2014), and rock magnetism investigations have been conducted. The ESR and rock magnetism studies focus on the production of ferromagnetic minerals in the slip zone due to thermal decomposition of paramagnetic minerals by frictional heating.…”