Why are composite volcanoes important?
Composite volcanoes are responsible for the most catastrophic eruptions in history. So far, Mars is the only place in the solar system besides Earth known to have stratovolcanoes.
What are the characteristics of composite volcano?
Composite volcanoes have the following characteristics:
- Acidic lava, which is very viscous (sticky).
- Steep sides as the lava doesn’t flow very far before it solidifies.
- Alternate layers of ash and lava. For this reason, they’re also known as stratovolcanoes .
- Violent eruptions.
- Longer periods between eruptions.
Is the Ol Doinyo Lengai volcano still active?
In October 2010, two separate lava flows and a small lava lake were photographed in an overflight. The volcano resumed natrocarbonatite lava flow which started to fill the large crater from the 2007-2008 eruption. As of July 2013, there is a large active hornito on the western edge of the crater floor.
What kind of minerals are in Ol Doinyo Lengai lava?
Whereas most lavas are rich in silicate minerals, the lava of Ol Doinyo Lengai is a carbonatite. It is rich in the rare sodium and potassium carbonates, nyerereite and gregoryite. Due to this unusual composition, the lava erupts at relatively low temperatures of approximately 510 °C (950 °F).
Where did the steam from Ol Doinyo Lengai come from?
According to Frederick Belton’s website, geologists that had climbed Ol Doinyo Lengai on 11 February saw periodic eruptions from a small fissure, and steam emissions from an area of the crater rim next to a part that had collapsed.
Where was the first eruptive phase of Oldoinyo Lengai?
Most of the volcano appears to be constructed by a thick sequence of yellow agglomerates and tuffs, interbedded with lavas. These deposits probably represent the earliest eruptive phase of Oldoinyo Lengai. They are exposed along the southern and eastern slopes of the volcano and in the gullies nearer to the base.