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What type of rock is basaltic flows?
igneous rock
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.
What type of magma is basaltic?
Viscosity of Magmas
| Summary Table | ||
|---|---|---|
| Magma Type | Solidified Rock | Chemical Composition |
| Basaltic | Basalt | 45-55 SiO2 %, high in Fe, Mg, Ca, low in K, Na |
| Andesitic | Andesite | 55-65 SiO2 %, intermediate in Fe, Mg, Ca, Na, K |
| Rhyolitic | Rhyolite | 65-75 SiO2 %, low in Fe, Mg, Ca, high in K, Na. |
What are basaltic lavas?
Basaltic lava, or mafic lava, is molten rock enriched in iron and magnesium and depleted in silica. Basaltic magmas are formed by exceeding the melting point of the mantle either by adding heat, changing its composition, or decreasing its pressure.
What is a dark rock formed from lava?
Basalt is a dark-colored igneous rock. Granite and Basalt are widely used for the construction of roads and buildings. Extrusive igneous rocks form when lava reaches the Earth’s surface a volcano and cools quickly. Most extrusive (volcanic) rocks have small crystals.
Why are basaltic rocks dark?
Basalt is usually dark grey to black in colour, due to its high content of augite or other dark-coloured pyroxene minerals, but can exhibit a wide range of shading. The physical properties of basalt reflect its relatively low silica content and typically high iron and magnesium content.
Is basaltic an explosive lava?
Basaltic eruptions are the most common form of volcanism on Earth and planetary bodies. The low viscosity of basaltic magmas inhibits fragmentation, which favours effusive and lava-fountaining activity, yet highly explosive, hazardous basaltic eruptions occur.
What are basaltic rocks made up of?
Basalts are common aphanitic igneous extrusive (volcanic) rocks. Basalts are composed of minute grains of plagioclase feldspar (generally labradorite), pyroxene, olivine, biotite, hornblende and <20% quartz.
What is a basaltic eruption?
How vesicular basalt is formed?
Vesicular basalt is formed when magma erupts from a volcano in the form of lava and it quickly hardens. This makes it an extrusive igneous rock….
What type of rock is a basalt?
This is a basalt, a dark coloured volcanic rock formed from a magma of basic composition erupted on the Earth’s surface. Magmas generally contain dissolved gas, which can form bubbles in the magma as the pressure is released on eruption. These bubbles can get trapped in the solidified rock.
What type of rock is amygdaloidal basalt?
Amygdaloidal basalt. This is a basalt, a dark coloured volcanic rock formed from a magma of basic composition erupted on the Earth’s surface.
Do all basalt rocks have gas bubbles?
Some have vesicles (gas bubbles); some do not. Some are gray, others are reddish or even greenish. Basalt is one of the most common rock types on Earth. Except for the coral, nearly all of the rocks of Hawaii are basalts. Much of Oregon and Idaho is covered with basalt.
What is the composition of basaltic lava?
Basalt Volcanic rock (or lava) that characteristically is dark in color (gray to black), contains 45 to 53 percent silica, and is rich in iron and magnesium. Basalticlavas are more fluid than andesitesor dacites, which contain more silica. Basaltis the most common rock type in the Earth’s crust(the outer 10 to 50 km).