2022年10月26日 · The three types of lava flow are pahoehoe, a’a, and pillow lava. Most lava flow is mafic or basaltic. Pahoehoe is smooth, a’a is rough, and pillow lava is rounded and only forms under water.

On Earth, 90% of lava flows are mafic or ultramafic, with intermediate lava making up 8% of flows and felsic lava making up just 2% of flows. [37] Viscosity also determines the aspect (thickness relative to lateral extent) of flows, the speed with which flows move, and …

2025年1月19日 · Mafic (ferromagnesian, dark-coloured) lavas such as basalt characteristically form flows known by the Hawaiian names pahoehoe and aa (or a’a). Pahoehoe lava flows are characterized by smooth, gently undulating, or broadly hummocky surfaces.

2017年4月25日 · Mafic Volcanoes: volcanoes that produce mafic lava have a very low explosivity due to the how easily the lava flows and how few volatiles (such as oxygen and silicon) are present within the lava. This forms shield volcanoes, which are gently sloping large volcanoes like those in Hawaii.

Because mafic lava is low viscosity, when it erupts from a volcano it flows downslope away from the vent, gradually cooling and crystallizing. Because of the relative ease of flow, basaltic volcanoes are broad, with gentle slopes.

Mafic lava is primarily responsible for forming the Hawaiian Islands. Two common forms of mafic lava flow are known by their Hawaiian names: pahoehoe and aa. Pahoehoe lava is billowy lava that is often wrinkled and ropy in appearance.

“Mafic” is a term used to describe the densest lava flows. The word derives from a composite of the chemical symbols for Magnesium (Ma) and Iron (Fe). This magma has a low viscosity, which allows for gases to escape the volcano, and for the lava flows to erupt calmly and predictably.

LAVA FLOW TYPES Mafic lava flows have been classically divided into two categories: pa-hoehoe and aa (e.g., Dutton, 1884; Macdonald, 1953). Pahoehoe is characterized by having a smooth surface, and aa has a spinose auto-breccia surface. In more recent years, some transitional types of basaltic lava have been noted, including slab pahoehoe and ...

2021年3月8日 · Mafic or basaltic lava flows: Basaltic or mafic lava means lower viscosity, which means it is more likely to flow readily. Basalt melts at an extremely high temperature because it contains more mafic minerals like olivine and pyroxene with extremely high melting temperatures.

Mafic lava flows have been classically divided into two categories: pahoehoe and aa (e.g., Dutton, 1884; Macdonald, 1953). Pahoehoe is characterized by having a smooth surface, and aa has a spinose autobreccia surface.