Granite may have more alkali feldspar, whereas a granite derived from partial melting of metaigneous rocks may be richer in plagioclase. It is on this basis that the modern "alphabet" classification schemes are based. The letter-based Chappell & White classification system was proposed initially to divide granites into I-type (igneous source) granite and S-type (sedimentary sources). Both types are produced by partial melting of crustal rocks, either metaigneous rocks or metasedimentary rocks. M-type granite was later proposed to cover those granites that were clearly sourced from crystallized mafic magmas, generally sourced from the mantle. However, this proposal has been rejected by
California Coastal Comm'n v. Granite Rock Co. still owns the land. California Coastal Comm'n v. Granite Rock Co. California Coastal Comm'n v. Granite Rock Co., 480 U.S. 572 (1987), is a United States Supreme Court case addressing the question of whether United States Forest Service regulations, federal land use statutes and regulations, or the Coastal Zone Management Act of 1972, preempt the California Coastal Commission's imposition of a permit requirement on operation of an unpatented mining claim in a national forest. The court ruled that even if federal land is not included in the Coastal Zone Management Act's interpretation of "coastal zone," the act does not automatically