Abstract:During the field work in the Jinling skarn iron deposit of Shandong Province, the authors discovered a Al-rich alkali metasomatite composed of spinel-corundum-alkali feldspar in Jinling complex on the southwestern slope of Huashan Mountain. Jinling rock body is a slightly basic-intermediate-intermediate (slightly alkaline) complex affected by late alkali metasomatite, which might be divided into gabbro diorite, biotite (amphibole) diorites, syenopegmatite and aplite dikes. In the rock body there are commonly lots of wall rock xenoliths of various sizes such as siliceous rocks with chert stripes and argillaceous hornfels,and the spinel-corundum-alkali feldspar metasomatite occurs just in the xenoliths. Being light white or dark grey in color, the metasomatite assumes massive form with local taxitic structure, and is composed of corundum (10%—25%), spinel (belonging chemically to ceylonite, (3%—7%), and anorthoclase (40%—55%) as well as small amounts of muscovite magnetite, rutile and zircon. Being genetically obviously different from complex corundum formed by metamorphism of clay deposit, it might be a metasomatic product formed through reaction between pegmatite fluids rich in late alkaline volatile components (Na2O+K2O) and xenoliths of Carboriferous strata (claystone, clayey shale or clayey hornfels) within the complex body.