megacrystic
Megacrystic is a type of igneous rock that contains one or more large minerals, known as megacrysts, which are typically larger than 5 centimeters in diameter. These megacrysts can be composed of a variety of minerals, including quartz, feldspar, or mafic minerals such as pyroxene and garnet.
Megacrysts typically form in subvolcanic or shallow intrusions, where magma has cooled slowly beneath the Earth's
The origins of megacrysts are often disputed among geologists. Some believe they form as a result of
Petrologists often use megacrysts as an indicator of the geochemical history of the magma. The composition
Megacrystic rocks are not commonly formed and can be found in limited areas around the world, primarily