Diorite

 

Date: Pre-Cambrian Era (1.6 billion years old)

 

Description: Diorite is an intrusive igneous rock, meaning it is formed by magma deep in the earth before it erupts from a volcano. Though relatively rare worldwide, it is fairly abundant in the Siouxland region because of the heavy volcanic activity that was present in region during Pre-Cambrian times. The diorite samples we have are some of the oldest rocks ever found in this region. This sample was found in Lein Quarry in Sioux Falls, SD.

 

Donor Information not available.

 

On display