even the rockery in the lake is reflective of all the different kind of geology in this Park.

Different layers of rock in Glacier can be dramatically different colors, and their color can tell us a great deal about their history. The process that created these striking colors centers around one element: Iron. The argillite in the park throughout its formation contained significant amounts of iron, which is a reactive metal. Much like metal on an old car, iron will oxidize (or rust) and turn reddish/orange when exposed to oxygen. The red colors in our rocks formed the same way! As the belt sea began to retreat, it exposed argillite and the iron within to oxygen, allowing for oxidation to occur.

Conversely, the green found in our rocks is a result of argillite forming without access to oxygen. Forming underwater in the belt sea, argillite starved of oxygen instead goes through a process known as reduction, with iron bonding to silica compounds. Under heat and pressure the iron-silicate minerals were converted to chlorite, a mineral which produced the green rocks found in the park today.