Please use this identifier to cite or link to this item:
Authors: Kuo, Li-Wei* 
Di Felice, Fabio* 
Spagnuolo, Elena* 
Di Toro, Giulio* 
Song, Sheng-Rong* 
Aretusini, Stefano* 
Li, Haibing* 
Suppe, John* 
Si, Jialiang* 
Wen, Cheng-Yen* 
Title: Fault gouge graphitization as evidence of past seismic slip
Issue Date: 2017
Series/Report no.: /45 (2017)
DOI: 10.1130/G39295.1
Abstract: One moderate- to large-magnitude earthquake (M > 6) nucleates in Earth’s crust every three days on average, but the geological record of ancient fault slip at meters-per-second seismic velocities (as opposed to subseismic slow-slip creep) remains debated because of the lack of established fault-zone evidence of seismic slip. Here we show that the irreversible temperature-dependent transformation of carbonaceous material (CM, a constituent of many fault gouges) into graphite is a reliable tracer of seismic fault slip. We sheared CM-bearing fault rocks in the laboratory at just above subseismic and at seismic velocities under both water-rich and water-deficient conditions and modeled the temperature evolution with slip. By means of micro-Raman spectroscopy and focused-ion beam transmission electron microscopy, we detected graphite grains similar to those found in the principal slip zone of the A.D. 2008 Wenchuan (Mw 7.9) earthquake (southeast Tibet) only in experiments conducted at seismic velocities. The experimental evidence presented here suggests that high-temperature pulses associated with seismic slip induce graphitization of CM. Importantly, the occurrence of graphitized fault-zone CM may allow us to ascertain the seismogenic potential of faults in areas worldwide with incomplete historical earthquake catalogues.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
kuo_2017_graphi.pdf755.67 kBAdobe PDFView/Open
Show full item record

Page view(s)

Last Week
Last month
checked on Nov 18, 2018


checked on Nov 18, 2018

Google ScholarTM