How do you describe a lava rock?
The term lava is also used for the solidified rock formed by the cooling of a molten lava flow. The temperatures of molten lava range from about 700 to 1,200 °C (1,300 to 2,200 °F). The material can be very fluid, flowing almost like syrup, or it can be extremely stiff, scarcely flowing at all.
What are the 3 textures of rocks?
Crystalline textures include phaneritic, foliated, and porphyritic. Phaneritic textures are where interlocking crystals of igneous rock are visible to the unaided eye. Foliated texture is where metamorphic rock is made of layers of materials.
Is lava rock smooth?
The glowing red-orange material is molten rock from deep below the Earth’s surface. When it erupts and flows on the surface, it is known as lava. A classic, smooth lava flow is like ketchup, while a rough lava flow is more like a thick or drying syrup.
What is the texture of a volcano?
Volcanic rocks are usually fine-grained or aphanitic to glassy in texture. They often contain clasts of other rocks and phenocrysts.
What is the composition of lava rock?
Lava rocks are composed of high amounts of iron and magnesium elements (collectively referred to as the ferromagnesian group) as well as calcium. Due to their chemical composition, basalts are the most abundant rock type of the ocean floor and Earth’s crust, and are the primary rock layer of the Hawaiian Islands.
What are the 4 different textures of igneous rocks?
Igneous Rock Textures
- COARSE GRAINED TEXTURE (PHANERITIC), mineral grains easily visible (grains several mm in size or larger)
- B) FINE GRAINED TEXTURE (APHANITIC), mineral grains smaller than 1mm (need hand lens or microscope to see minerals)
- C) PORPHYRITIC TEXTURE (MIXED FINE AND COARSE)
Can lava be pink?
The color of lava depends on the temperature of the flow as well as the chemical composition and any impurities that are in the liquid rock. Colors can include black, red, gray, brown and tan, metallic sliver, pink, and green. When lava cools it also forms a myriad of different shapes and types of lava.
Why are some lava rocks white?
Rhyolite. Rhyolite is light-coloured or white – this is a clue that the rock contains a lot of silica (more than 70%) and not much iron or magnesium. Pumice, a rhyolite, is very common in the central North Island. It may still have evidence of the bubbles of gas trapped as the rock solidified.
What texture are intrusive rocks?
phaneritic
The texture of an igneous rock made up entirely of crystals big enough to be easily seen with the naked eye is phaneritic. Phaneritic texture is sometimes referred to as coarse-grained igneous texture. Granite, the most well known example of an intrusive igneous rock, has a phaneritic texture.
Is lava intrusive or extrusive?
Lava is magma that pushes up through the Earth’s crust to the surface. When magma and lava cool and harden, they create igneous rocks. These rocks may be extrusive or intrusive, depending on where the magma or lava crystallizes. Basalt is the most common extrusive rock while granite is a very common intrusive rock.
What is the texture of lava?
Two types of lava are named according to the surface texture: ʻAʻa (pronounced [ˈʔaʔa]) and pāhoehoe ([paːˈho.eˈho.e]), both Hawaiian words. ʻAʻa is characterized by a rough, clinkery surface and is the typical texture of viscous lava flows.
How does a vesicular texture in a volcanic rock develop?
Vesicular texture is a volcanic rock texture characterised by, or containing, many vesicles. The texture is often found in extrusive aphanitic, or glassy, igneous rock. The vesicles are small cavities formed by the expansion of bubbles of gas or steam during the solidification of the rock.
What volcanic rock is cooled lava made up of?
When lava reaches the surface of the Earth through volcanoes or through great fissures the rocks that are formed from the lava cooling and hardening are called extrusive igneous rocks. Some of the more common types of extrusive igneous rocks are lava rocks, cinders, pumice, obsidian , and volcanic ash and dust.