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Why are the crystals in pillow basalt than those in many other examples of basalt?
Wiki User
∙ 7y ago
A factor that determines crystal size in igneous rocks is the speed in which the lava/ magma crystallised or froze. As pillow basalts form at mid ocean ridges where magma is erupted into direct contact with the cold sea water the crystals form very fast and are therefore small. Other basalts erupted on land still have relatively small crystals and crystallised relatively fast but overall slower then pillow basalts.
June Douglas
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How do you differentiate granite from basalt?
Although they are both igneous rocks which have solidified from magma, granite is an intrusive igneous rock and basalt is an extrusive igneous rock. As an extrusive igneous rock, the magma that formed granite had a long time to cool underground, and therefore consists of larger, visible mineral crystals. Basalt on the other hand, cooled rather rapidly from magma after eruption from a volcano and therefore is aphanitic, with crystals too small to be seen with the naked eye. There is also a difference in chemistry. Granite is considered felsic, with a preponderance of silicate minerals like quartz and orthoclase feldspar. Basalt is considered mafic, with an abundance of heavier minerals like olivine and amphibole, thus making it heavier than granite. These minerals also give basalt a dark color compared to the lighter colored granite.
How can you tell that sandstone is older than a basalt layer?
If the sandstone is below the basalt layer, it is older. Though caution is advised, to make sure it is really a basalt layer and not an intrusion of gabbro. Other indicators that the sandstone is older is evidence of alteration to the sandstone where the two meet (called a "baked contact") and pieces of sandstone being found in the the basalt.
Pillow lavas are associated with?
Pillow lava is associated with submarine basaltic eruptions. Although they are usually basaltic, they can have other compositions as well.
Is crystal a precious stone?
It depends. All gemstones other than pearls and opals are crystals, but most crystals are not gemstones.
What is the type of magma Mt fuji has?
Scientists have identified distinct phases of volcanic activity in the formation of Mt. Fuji. The first phase is composed of an andesite which forms the deep core of the volcano and this is covered by later basalt lavas.
Why are the crystals in pillow basalt smaller than those of in many other examples of basalt?
A factor that determines crystal size in igneous rocks is the speed in which the lava/ magma crystallised or froze. As pillow basalts form at mid ocean ridges where magma is erupted into direct contact with the cold sea water the crystals form very fast and are therefore small. Other basalts erupted on land still have relatively small crystals and crystallised relatively fast but overall slower then pillow basalts.
Why are the crystals in pillow basalt smaller than those in many other examples of basalt?
A factor that determines crystal size in igneous rocks is the speed in which the lava/ magma crystallised or froze. As pillow basalts form at mid ocean ridges where magma is erupted into direct contact with the cold sea water the crystals form very fast and are therefore small. Other basalts erupted on land still have relatively small crystals and crystallised relatively fast but overall slower then pillow basalts.
Why are crystals in pillow basalt smaller then ones in basalt?
A factor that determines crystal size in igneous rocks is the speed in which the lava/ magma crystallised or froze. As pillow basalts form at mid ocean ridges where magma is erupted into direct contact with the cold sea water the crystals form very fast and are therefore small. Other basalts erupted on land still have relatively small crystals and crystallised relatively fast but overall slower then pillow basalts.
Why are the Crystal's in pillow basalt smaller than those of in other example of basalt?
Pillow basalts are lavas that were erupted and cooled in sea water. Therefore, they have had very little time to form crystals of any size, during rapid solidification, when compared to most land or air-born eruptions.
Why are the crystals in pillows basalts smaller than those in many other examples of basalts?
A factor that determines crystal size in igneous rocks is the speed in which the lava/ magma crystallised or froze. As pillow basalts form at mid ocean ridges where magma is erupted into direct contact with the cold sea water the crystals form very fast and are therefore small. Other basalts erupted on land still have relatively small crystals and crystallised relatively fast but overall slower then pillow basalts.
What are some more examples extrusive igneous rocks?
Some other examples are Andesite, Basalt, Rhyolite, and Scoria.
Does halite have cleavage or fracture?
Basalt does not exhibit cleavage, only fracture.
What other kinds of food are in the form of crystals?
Maple syrup and honey are two good examples.
How the moon reflects sun lights .Is with the help oxygen crystals present on surface of moon?
There are no oxygen crystals on the moon. The moon's surface is made of a rock called basalt, a rock that can be found on Earth as well. The moon reflects sunlight just like any other object does.
Is granite a phaneritic rock?
Granite is a phaneritic rock. Phaneritic rocks are coarse-grained, and they have visible crystals. Other phaneritic rocks include diorite, gabbro, and periodite. These rocks are also intrusive because they cool slowly.
Is basalt equal to granite?
No. Basalt is extrusive whilst granite is intrusive, among other things.
How are intrusive and extrusive classified?
Intrusive or extrusive describe properties of an igneous rock. An intrusive rock is formed within the crust and it insulated and cooled slowly. Some examples of an intrusive rock include diorite, granite, gabbro, and periodite. They have large grains because they have more time for growth. On the other hand, extrusive rocks cool at the surface rapidly. They are comprised of tiny crystals and/or glass. Some examples include rhyolite, andesite, and basalt.
