Concentric Circles Pattern
When minerals are formed in magma, the elements of these minerals diffuse which create concentric circles like tree rings. During this process, the minerals are made in some parts that have enough specific elements, if not they don’t form. So, concentric circle pattern is formed when the two parts are alternately repeated.
When several rings of a concentric circle pattern are formed by minerals it is calld a ‘Lisegang ring’.
If magma cools down slowly, there is enough time to grow minerals so they can have a normal shape. However, if it cools down very quickly, the time to grow is lacking, so the magma becomes overcooled, preventing minerals form growing. As a result, the radially stretched lines are formed around one point.
How was the Flowerstone in Cheongsong Created?
The flowerstone in Cheongsong created when magma cooled down very rapidly. Rapid cooling caused the minerals to also grow quickly and in that process concentric cicles and radial patterns were created by the combination of various processes as the foregoing describes.
What is the spherulitic Rhyolite(flowerstone)?
Rocks at this location have concentric circle patterns or patterns that are formed by color alternations of dark and white or straight line segments coming form the center of circle depending on the mineral arrangement. In theis manner, a spherulitic texture is formed from particles in rock. The rocks with clear spherulitic textures are called Spherulites.
Especially, we can see various spherulitic textures in the rhyolite in Cheongsong, so it is called a sperulitic rhyolite.
Rhyolite: a fine-grained igneous rock created while the magma cools down in a short tome, comsisting of lot of silica