Question

A clastic rock composed of sand-sized grains derived from the physical weathering of granite and containing a sizable proportion of feldspar is termed ________.

Answer 1

A clastic rock composed of sand-sized grains derived from the physical weathering of granite and containing a sizable proportion of feldspar is termed as arkose.  It is a sedimentary rock that has a composition of at least 25% feldspar. It is a type of sandstone that has a coarse texture and is commonly in gray or pink in color. The most important minerals in arkose are feldspar and quartz. And, it is quartz that is dominant in composition. This rock is formed from weathering of metamorphic or igneous rock that are rich in feldspar. They are to be quickly deposited into cold environments so as to avoid chemical weathering.