This series is designed to illustrate the sequence at which each igneous rock type crystallizes. The fastest rock types to crystallize are on the top of Bowen’s Reaction Series, and the slowest to crystallize are on the bottom. The right branch of the series is called the Continuous Reaction Series. This series becomes progressively more sodium rich. At each stage of the Discontinuous Reaction Series, which is the upper left branch on Bowen’s Reaction Series, a different silicate structure emerges.

Ultramafic Rock Type: This rock type requires the highest temperatures of crystallization. They are the first to crystallize, and are rich in calcium. Olivine and Pyroxene are some examples of utramafic rocks.

Basaltic (Mafic): These rocks don’t quite cool as quickly as the ultramafic rocks. Gabbro, Basalt, Calcium Feldspar and pyroxene are all basaltic rocks. These are also usually darker in color because there is more Magnesium and Iron

Andesitic (Intermediate): This rock type is located in the middle of Bowen’s Reaction Series and is made up of rocks such as Diorite, Andesite, Biotite Mica.

Granitic (Felsic): These rocks are highly concentrated, found at the bottom of Bowen’s Reaction Series, and are the last to cool.

Relative Dating- Rocks are placed in their proper sequence of formation.

Unconformity: break in the rock record, represents a long period of time when deposition ceased, erosion occurred and then deposition resumed. There are 3 different types of unconformities:

             1) Disconformity: the most common type of unconformity, and run parallel to the strata. Their existence can sometimes be difficult to identify because a disconformity blends in with ordinary bedding. Other times due to evident erosion a disconformity is easily identified.

             2) Angular Unconformity: These are the most distinguishable unconformity because, as the name defines, angular conformity consists of angled or folded sedimentary rock. Process: deposition occurs, folding takes place, deposition stops, folding and weathering occur and finally deposition resumes. This type of unconformity suggests a period of deformation occurred.

             3) Nonconformity: These occur when sedimentary rock comes in contact with metamorphosis and igneous rock. In order for a nonconformity to be present there must be a period of erosion and uplifting. The igneous mass then breaks through the layers of deposited sediment forming an amoebic shaped layer. If the nonconformity reaches the surfaces it is subject to weathering just as every other layer is.

Laws of Relative Dating:

1) Law of Superposition: the oldest layer is on the bottom. Each bed is order than the one above, and younger than the one below.

2) Law of Original Horizontality: layers of sediment are generally deposited in a horizontal position.

3) Law of Crosscutting Relationships: All of the layers had to be there in order for magma to cut through. This law applies to any nonconformity such as igneous bodies cutting through the strata.