Abstract
The strain rates associated with the production of various microstructures in naturally deformed quartzites can be estimated by comparing them with experimentally produced equivalents. Fast, medium and slow strain rate ranges can be distinguished with values, at 350°C, of greater than 10 −3 sec −1 , between 10 −4 to 10 −9 sec −1 , and less than 10 −9 respectively. The strain rate producing normal tectonite textures is estimated at 3 × 10 −14 sec −1 at 350°C.