矽镁层 Traditional form: 矽鎂層 Pinyin (reading): xīměicéng Definitions: sima (geology) silicon and magnesium layer in earth's crust Characters: 矽 - silicon 镁 - magnesium 层 - layer, floor, story, stratum Traditional characters: 矽 - silicon 鎂 - magnesium 層 - layer, floor, story, stratum