Evolution of Hydromechanical Coupling from Quartz to Shale rich Faults and Implications for Slip stability

Fault rock heterogeneity has a dominant effect on frictional and fluid flow properties of faults, yet the study of how fault hydromechanical properties are coupled, evolve with fault fabric and influence slip behaviour is still in its infancy. Here, we show that the increase in shale content within a quartz-rich experimental fault promotes a fabric evolution from a load-bearing granular framework to an interconnected foliated and clay-rich network. This fabric evolution causes a significant reduction in frictional strength, a marked decrease in permeability, and enhanced frictional stability. Fault stability is enhanced by fault dilation associated to a reduction in pore fluid pressure within the low permeability, clay-rich faults. Our results indicate that fault rock fabric and associated hydromechanical properties exert a primary control on fault slip behaviour. The enhanced stability within pressurized clay-rich faults matches well with observations of aseismic slip during hydraulic stimulations of shales and models proposing dilation strengthening as a mechanism for the occurrence of slow slip events in shale rich sediments at shallow crustal levels.

this repository contains the raw data for all experiments reported in Table 1. 

Furthermore, you are able to reproduce each figure by executing the Python code in each .zip file. 

For most of the codes you will have to install rawPy that  is a specific Python package to manipulate our lab data and can be found at

https://github.com/marcoscuderi/rawPy

for any further request please do not hesitate to contact me at marco.scuderi@uniroma1.it