The Rock Cycle

Properties of Rocks Physical and chemical properties are determined by HOW and WHERE the rock was formed.

Properties continued Physical characteristics reflect the chemical composition of the rock as a whole or of the minerals that make up the rock

Properties continued The rate at which rock weathers and breaks apart is determined by the chemical stability of the minerals in the rock.

Bowen’s Reaction Series As magma cools certain minerals crystallize first. As minerals form, specific elements are removed from the magma. (changing the composition of the magma) This change allows different minerals with different composition to form.

Bowen’s Reaction Series

Chemical Stability of Minerals Chemical stability- measure of the tendency of a chemical compound to maintain its original chemical composition rather than break down to form a different chemical. Stable minerals form at the lowest temperatures (conditions similar to surface) Unstable minerals form at the highest temperatures. ( conditions different than on Earth’s surface)

Physical Stability of Rocks Rocks have natural “zones of weaknesses” determined by how and where they form. Sedimentary rocks- form in layers, tend to break between the layers Metamorphic rock tend to break in layers that from from mineral alignment Massive igneous rock structures have joints which cause the rock to break into columns.