• (a.) Broken in place; -- said of rocks having a broken or brecciated structure due to crushing, in contrast to those of brecciated materials brought from a distance.
Au`to·clas'tic adjective [ See Auto- ; Clastic .] (Geol.) Broken in place; -- said of rocks having a broken or brecciated structure due to crushing, in contrast to those of brecciated materials brought from a distance. 
In geology the term autoclastic describes rocks having a broken or brecciated structure due to crushing, in contrast to those of brecciated materials brought from a distance.
descriptive of a rock that has fractured in situ