Now we shall look more closely at the geologic materials that make up the bedrock of Minnesota. The letters of the geological alphabet. If iron and magnesium are abundant together with silicon and oxygen, we call the minerals ferromagnesian silicates . These minerals are generally light-colored and less dense . Feldspar and quartz are the most common non-ferromagnesian silicates.
Carbonate minerals are the most important non-silicate mineral group for our study.
These minerals contain various chemical elements in combination with carbon and oxygen. Rocks are interrelated to one another in the rock cycle , which describes the way in which both internal and external processes on Earth operate to create and modify earth materials. Igneous rocks These rocks form by the solidification of molten rock which is called magma beneath the surface and lava above the surface. The magma is created by heat sources, either at spreading centers or in subduction zones. Hence, igneous rocks are often formed by processes operating at plate boundaries .