[3] In the broad sense[2][4] of the term, volcaniclastics includes pyroclastic rocks such as the Bandelier Tuff;[5] cinder cones and other tephra deposits; the basal and capping breccia that characterize ʻaʻā lava flows; and lahars and debris flows of volcanic origin.
[2] Volcaniclastics are composed of a range of pyroclastic detritus mixed with epiclastic sediments and formed in variable depositional environments.
[1] Autoclastic volcanic material is produced by processes active during movement of solid or semisolid lava.
[11][15][16] The Espinaso Formation of New Mexico is an example of a rock unit that is composed of a complex mixture of pyroclastic and volcanic epiclastic material and so is described simply as volcaniclastic.
[18] Mixed pyroclastic-epiclastic deposits may be classified by average clast size and percentage of pyroclastic material.