Phonolite is an uncommon shallow intrusive or extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grained) to …

2023年11月20日 · Phonolite is a type of volcanic rock that belongs to the family of igneous rocks. It is characterized by its unique mineral composition and texture, which set it apart from other …

Phonolite, any member of a group of extrusive igneous rocks (lavas) that are rich in nepheline and potash feldspar. The typical phonolite is a fine-grained, compact igneous rock that splits into …

2019年12月5日 · We know that the Tower is formed of a rare igneous rock, phonolite porphyry, and is the largest example of columnar jointing in the world. To better understand processes …

2024年6月17日 · The crystalline igneous rock that composes Devils Tower is classified as phonolite porphyry. Phonolite is a type of fine-grained igneous rock composed primarily of the …

2024年12月3日 · The geologic composition of Devils Tower is predominantly phonolite porphyry, a rare igneous rock. This unique formation is also the largest example of columnar jointing in …

The crystalline igneous rock that composes Devils Tower is classified as phonolite porphyry. Phonolite is a type of fine-grained igneous rock composed primarily of the mineral feldspar. A …

2024年5月7日 · Porphyritic phonolite or phonolite porphyry has well-formed, large leucite, nepheline, and alkali feldspar crystals in a fine-grained matrix. The larger crystals are known …

2024年5月8日 · A porphyry (plural porphyries) is an igneous rock with large, well-formed mineral grains set in a finer-grained matrix. Such rocks have two distinctive crystal sizes: large and small.

Porphyry (/ ˈpɔːrfəri / POR-fə-ree) is any of various granites or igneous rocks with coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate -rich, generally aphanitic …