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.
Generally, membership in a discourse community requires a certain level of expertise in the common goal; the more expert one is considered, the more influence one has over the preferred discursive practices.