Andesite is an aphanitic (fine-grained) to porphyritic (coarse-grained) igneous rock that is intermediate in its content of silica and low in alkali metals. It has less than 20% quartz and …

2023年7月3日 · Andesite is a fine-grained, intermediate volcanic or extrusive igneous rock. Its composition lies between basalt and dacite, and it has mainly sodium-rich plagioclase and one …

2023年9月4日 · Andesite is volcanic rock named after the Andes Mountains. Intermediate in silica content, it is usually gray in color and may be fine-grained or porphyritic. Andesite is the …

Andesite is the name of a family of fine-grained, extrusive igneous rocks that are usually light to dark gray in color. They have a mineral composition that is intermediate between granite and …

andesite, any member of a large family of rocks that occur in most of the world’s volcanic areas. Andesites occur mainly as surface deposits and, to a lesser extent, as dikes and small plugs.

Andesite is an extrusive igneous rock composed primarily of plagioclase feldspar and large amounts of mafic minerals like hornblende. It has an aphanitic texture, meaning its interlocking …

2018年8月10日 · Andesite is a type of igneous rock that is formed by volcanic activity. It is usually dark grey or bown in colour. It usually exists as the solid form of volcanic lava or magma. The …

Andesite is a fine-grained volcanic rock (aphanitic texture) that forms through the rapid cooling of magma at the Earth’s surface. Its silica content ranges from 57-63%, placing it between the …

2024年2月15日 · Andesite is an igneous volcanic rock containing between about 52 and 63 weight % silica (SiO2). Andesite is the extrusive equivalent to plutonic diorite - if a dioritic …

Andesite is an extrusive volcanic rock. It is an intermediate type between basalt and rhyolite. It is fine-grained in texture and is sodium-rich plagioclase and pyroxene or hornblende. The …