The role of dilation and cementation in the formation of cataclasite in low temperature deformation of well cemented quartz-rich rocks

In fault zones, where cataclasite is well developed and shearing is unequivocal, the fine-grained quartz matrix representing up to 50% of the fault rock volume has characteristics similar to those in the tabular bands. We interpret these volumes to be in many cases a result of cement precipitation rather than as a product of comminution. If correct, then the brittle deformation of well cemented, quartz-rich rocks deformed at low temperatures involves much more dilation and cementation than previously recognized.