Mount Kino is a volcanic mountain located in Maine, USA. The mountain is composed of rhyolite, which is an extrusive igneous rock that is high in silica content. Rhyolite is formed when magma cools and solidifies quickly, usually due to its eruption onto the earth's surface.
The rhyolite found at Mount Kino, often referred to as “Kineo Flint”, is characterized by its fine-grained texture and light color, often ranging from white to pink or gray. This rock is also known for its abundance of phenocrysts, which are large crystals that are embedded within the fine-grained matrix. The most common phenocrysts found in Mount Kino rhyolite are quartz, feldspar, and biotite mica.
In terms of mineral composition, Mount Kino rhyolite is dominated by quartz and feldspar, which make up over 90% of the total mineral content. Other minerals present in smaller quantities include biotite mica, hornblende, and various accessory minerals such as zircon and apatite.
Geologically speaking, Mount Kino rhyolite is part of the Coastal Volcanic Belt, which stretches along the eastern seaboard of North America. This volcanic belt is characterized by its extensive outcrops of rhyolitic rocks, providing a unique opportunity to study the geology and mineralogy of this important rock type.
The Rhyolite from Mount Kineo was highly sought after by Native American Tribes that traveled vast distances to trade with the local tribes for this precious resource. (We dig into this aspect of the Moosehead Lake Region in another blog post.)
Mount Kino rhyolite is a fascinating and unique rock type with a rich mineralogy and geological history. Its fine-grained texture, abundance of phenocrysts, and distinctive mineral composition make it a popular choice for geological study and a valuable addition to any rock collection.