Medium-grained rocks can be composed of quartz grains, feldspar grains (arkose), or rock fragments and clay (graywacke). Sandstone (Photograph by Parvinder Sethi). Medium-sized grains in clastic sedimentary rocks form sandstone. This sample is a quartz sandstone.
Bliss â¢ McCabe: Discourse Genres 135 special interests and can give lengthy descriptions ofrelevant objects such as rocks or music).â¢ We have identified the following components thatappear to be necessary for a complete proceduraldiscourse regarding how a game is played: goals,players, materials, and procedures.
Discourse community A discourse community is essentially a group of people that shares mutual interests and beliefs. âIt establishes limits and regularities...who may speak, what may be spoken, and how it is to be said; in addition [rules] prescribe what is true and false, what is reasonable and what foolish, and what is meant and what not.â (Porter, 39).