because the last ice age removed the top sediment layer of the soil, the kola peninsula is on the surface extremely rich in various ores and minerals, including apatites and nephelines; copper, nickel, and iron ores; mica; kyanites; ceramic materials, as well as rare-earth elements and non-ferrous ores. deposits of construction materials such as granite, quartzite, and limestone are also abundant. diatomaceous earth deposits are common near lakes and are used to produce insulation.