More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System.

2010年5月6日 · There are three types of basalt lava flows: pillow, pahoehoe, and a'a. Pillow lava. Pillow lavas are volumetrically the most abundant type because they are erupted at mid-ocean ridges and because they make up the submarine portion of seamounts and large intraplate volcanoes, like the Hawaii-Emperor seamount chain.

Basaltic lava flows, particularly pāhoehoe flows, may have a variety of surface features including hornitos, levees, tumuli, pressure ridges, and squeeze-ups. Highly vesiculated region near the top of a basaltic lava flow in Craters of the Moon National Monument.

Basaltic lava flows may travel many miles (kms) from their vents, and up to hundreds of miles (kms) in the case of extremely large lava flows known as flood basalts. Lavas that contain more silica are more viscous than basaltic ones.

2024年1月28日 · Mid-ocean ridges create most basaltic rocks and new oceanic crust and are dominated by pillow lava, with some having sheet flow and lobate lava. Examples are the East Pacific Rise, Mid-Atlantic Ridge, and Gakkel Ridge.

2023年4月18日 · Columnar jointing is most commonly found in basaltic lava flows, but it also occurs in lava flows of other compositions, pyroclastic flow deposits (ignimbrites), in some lava domes, volcanic necks, and even in some shallow intrusions.

2024年10月10日 · Basaltic lava, a prevalent volcanic rock on Earth, significantly influences the planet’s surface. Known for its fluidity and relatively low viscosity, basaltic lava contributes to forming new landmasses and shaping geological features. Understanding basaltic lava involves exploring its forms, chemical makeup, and formation processes.

Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form in small intrusive bodies, such as an igneous dike or a thin sill. It …

Basalt is a hard, black volcanic rock with less than about 52 weight percent silica (SiO2). Because of basalt's low silica content, it has a low viscosity (resistance to flow). Therefore, basaltic lava can flow quickly and easily move >20 km from a vent.

Basaltic lava flows erupt primarily from shield volcanoes, fissure systems, scoria cones, and spatter cones. These fluid lava flows can be subdivided into two end-member structural types, based primarily on the nature of lava flow surfaces: Pahoehoe Lava-- Surfaces are smooth, billowy, or ropy.