Clay Gouges in the San Andreas Fault System and their Possible Implications

Clay mineral formation and fabric development in the DFDP-1B borehole, central Alpine Fault, New Zealand

“…Similar smectite clay minerals were detected in other continental transform zones including, for example, the San Andreas Fault in Parkfield, California Schleicher et al 2006;Schleicher et al 2010), where they can form a network of clay coatings on rock surfaces due to local infiltration of fluids during creep. In addition, Wu et al (1975) observed smectite in fault gouge at the northern and central section of the San Andreas Fault Zone and along the Calaveras and Hayward faults, while Chester et al (1993) showed that cataclastic and fluid-assisted processes in the cores of the Punchbowl and the San Gabriel faults are due to pervasive syntectonic alteration of the host rock minerals to zeolites and clays.…”

“…Fault gouge composition and clay formation Low-temperature solution transfer during and/or after transient conditions of fault movement often leads to the alteration of the faulted rock and the formation of clay minerals (Wu et al 1975;Evans & Chester 1995;Morrow et al 2001;Kitagawa et al 2007;Schleicher et al 2009). The mineralogic composition of fault gouge is therefore a strong indication of the conditions that prevailed during fault rock formation.…”

“…Wu et al 1975;Saffer & Marone 2003;Collettini et al 2009). Along the surface exposures of the Alpine Fault in the South Island of New Zealand, the significance of clay minerals has been previously documented at Gaunt Creek.…”

Structure and dynamics of water on muscovite mica surfaces

“…Phyllosilicates (i.e. clay minerals and mica) are ubiquitous in natural fault zones (Wu et al, 1975;Rutter et al, 1986;Chester et al, 1993;Wintsch et al, 1995;Uda et al, 2001;Otsuki et al, 2005) and these layer-structure minerals lead to the low frictional strength of the fault zones (Shimamoto and Logan, 1981;Logan and Rauenzahn, 1987;Morrow et al, 1992). One of the reasons for the low frictional strength of phyllosilicates-bearing fault would be due to the lubrication of adsorbed and interlayer water molecules on these phyllosilicate minerals (Morrow et al, 2000).…”

Structure and dynamics of water on Li+-, Na+-, K+-, Cs+-, H3O+-exchanged muscovite surfaces: A molecular dynamics study

“…The deformation of rocks in the Earth's crust is often localized within fault zones as continued slip, and slip behavior strongly depends on the frictional strength of these fault zones. Phyllosilicates (i.e., clay minerals and mica) are ubiquitous in natural fault zones (Wu et al, 1975;Rutter et al, 1986;Chester et al, 1993;Wintsch et al, 1995;Uda et al, 2001;Otsuki et al, 2005) and these layer-structure minerals lead to the low frictional strength of the fault zones (Shimamoto and Logan, 1981;Logan and Rauenzahn, 1987;Morrow et al, 1992). One of the reasons for the low frictional strength of a phyllosilicate-bearing fault is the lubrication provided by adsorbed and interlayer water molecules on these phyllosilicate minerals (Morrow et al, 2000).…”