A new study of samples from these more leisurely fault sections has revealed that tiny particles of clay [less than 100 nanometers thick] keep these sections lubricated and less likely to violently shake.
… Some have speculated that fluids facilitate slippage, while others have focused on serpentine ” a greenish material that can chemically react to form talc (the mineral that in loose form is commonly known as talcum powder).
But geologist Ben van der Pluijm and colleagues at the University of Michigan and Germany’s Ernst-Moritz-Arndt Universität Institut für Geographie und Geologie found that neither of these was the explanation.
Cool. Nanocoating as lubricant.
Also cool: SAFOD or the San Andreas Fault Observatory at Depth.
Came very close to attending graduate school at Michigan to work with van der Pluijm, co-author with my undergraduate advisor, Stephen Marshak, of Earth Structure – An Introduction to Structural Geology and Tectonics. Good thing I didn’t or I’d have been a … no, don’t say it … Wolverine.
