Rich in silicon and aluminum

• Rock formation
• Upper layer of earth's crust
• Earth's crust
• Some of the upper crust is backing a Liberal
• The granite-like rocks that form the outermost layer of the earth's crust
• Part of the earth's crust

WordNet Word definitions in WordNet
n. the granite-like rocks that form the outermost layer of the earth's crust; rich in silicon and aluminum

Wikipedia Word definitions in Wikipedia
In geology , the sial refers to the composition of the upper layer of the Earth 's crust , namely rocks rich in silicates and aluminium minerals. It is sometimes equated with the continental crust because it is absent in the wide oceanic basins , but "sial" ...