Tectonics and Structural Geology

Fault rocks

Features from the Field: Shear Zones and Mylonites

Samuele Papeschi, Sandra McLaren and Hannah Davies January 25, 2021

Dextral, ductile shear zones crosscut foliated schist at Cap de Creus (Catalona, Spain). Photo © Jordi Carreras

The San Andreas Fault in California, the Alpine Fault in New Zealand, or the Main Frontal Thrust in the Himalayas are some of the most famous and largest fault zones that accommodate the relative displacement between two adjacent crustal blocks. Such faults, however, represent only the shallower expression of something much bigger: a crustal shear zone. In the first 10 kilometers or so of the crus ...[Read More]

TS Must-Read – Sibson (1977) Fault Rocks and Fault Mechanism

The Must-read team December 28, 2020

The paper “Fault Rocks and Fault Mechanisms” by R. H. Sibson (1977), was one of the first studies that established major connections between the rocks that form in faults, and their conditions and mechanics during formation at crustal scale. Concretely, Sibson (1977) established: 1.) links among the textures and lithologies that develop along fault zones (fault rocks), 2.) the rheological and crus ...[Read More]