0
What does grain-size tell you about the cooling history of a rock?
gp9029
Slower rates of cooling will create larger crystals. Rapid cooling allows little time for element accumulation in the crystal, therefore, the crystals created will be smaller.
Larger, visible crystals in igneous rock indicate that the magma was slow cooling, usually at depth. Much smaller crystals in igneous rock indicate rapid cooling of lava, usually at or near the surface. Crystals in igneous rock will grow larger and have more time to accumulate material for their growth the more time they have at their crystallization temperature.
Wiki User
∙ 11y ago
Wiki User
∙ 9y agoGrains are crystals.
Crystals take time to grow.
Small crystals therefore mean that they did not have time to grow very big before the rock turned solid = rapid cooling
Large crystals therefore mean that there was time for the crystals to grow before the rock turned solid = slow cooling.
Wiki User
∙ 13y agoThe slower the rate of cooling the larger the size of the crystals that can develop.
Wiki User
∙ 11y agothe longer it takes to cool, the more time the crystals have to form
Add your answer:
Earn +20 pts
How could you tell an older rock from a younger rock just by looking at their isochrons?
You could tell an older rock from a younger rock by looking at it because the older rock isochron would have a steeper slope.
How do you tell if your pet rock is dead?
a rock is never alive
How can you tell whether a rock cliff beside a highway is made of igneous rock or sedimentry rock?
sedimentary rock is a multiple of layers
How did Ernest Everett Just change history?
no. you tell me how he changed history.
Is the moon sedimentary rock?
yes they are you have to look at a normole one can tell you
How do you tell if a rock is intrusive?
Intrusive rocks are formed from cooling magma beneath the surface. The opposite would be an extrusive rock, these rocks form from lava cooling on the surface of the earth.
How is texture related to cooling history?
The slower a mineral cools, the larger the crystals it forms. Rapid cooling produces fine grained rocks / minerals, while slow cooling produces large grained rocks / minerals. In the case of igneous rocks, for example, you can tell whether it was formed inside the earth and underwent slow cooling (like granite) or was formed during extrusion from the earth, (such as during a volcanic eruption), which would expose it to water or air, cooling it rapidly. If it has large, chunky crystals, in is an intrusive rock, formed inside the earth, and cooled very slowly. If it is very fine grained or has no grains, (such as obsidian), it is an extrusive rock.
What the rock says?
If you learn to read them (study Geology) the rocks tell you the past history of our planet.
How can you tell if a rock cooled fast or slow?
You would examine a fracture surface of the rock. Intrusive igneous rocks that have cooled very slowly underground have visible crystals and are said to have a phaneritic texture. Granite is an example of this type of rock. Extrusive igneous rocks that have cooled quickly from lava above or on the surface generally will have crystals too small to be visible with the naked eye, in a texture that is referred to as aphanitic. Obsidian is an example of this type of rock.
What can texture tell us about the history of the rock and melt?
The initial composition of the magma is dictated by the composition of the source rock and the degree of partial melting.
How can tell igneous and metamorphic rocks apart?
Igneous rock forms from the cooling of magma. This forms a rock that is uniform in composition, and sometimes contains air pocketed texture from the process of cooling. Sedimentary rock is formed of small bits of dirt and stone that bind together after they settle as sediment. This rock is usually distinguishable by the flecks of different types of rock and dirt. Metamorphic rock is any type of rock that is transformed by heat, pressure, or chemical changes. It often becomes denser and smoother than the rock from which it changed.
How can you tell sedimentary rocks and igneous rocks apart?
Igneous rock forms from the cooling of magma. This forms a rock that is uniform in composition, and sometimes contains air pocketed texture from the process of cooling. Sedimentary rock is formed of small bits of dirt and stone that bind together after they settle as sediment. This rock is usually distinguishable by the flecks of different types of rock and dirt. Metamorphic rock is any type of rock that is transformed by heat, pressure, or chemical changes. It often becomes denser and smoother than the rock from which it changed.
How can you tell igneous and metamorphic apart?
Igneous rock forms from the cooling of magma. This forms a rock that is uniform in composition, and sometimes contains air pocketed texture from the process of cooling. Sedimentary rock is formed of small bits of dirt and stone that bind together after they settle as sediment. This rock is usually distinguishable by the flecks of different types of rock and dirt. Metamorphic rock is any type of rock that is transformed by heat, pressure, or chemical changes. It often becomes denser and smoother than the rock from which it changed.
How can you tell igneous and metamorphic rocks apart?
Igneous rock forms from the cooling of magma. This forms a rock that is uniform in composition, and sometimes contains air pocketed texture from the process of cooling. Sedimentary rock is formed of small bits of dirt and stone that bind together after they settle as sediment. This rock is usually distinguishable by the flecks of different types of rock and dirt. Metamorphic rock is any type of rock that is transformed by heat, pressure, or chemical changes. It often becomes denser and smoother than the rock from which it changed.
What does grain size tell you about the orgin and cooling time of an igneous rock?
The larger the crystals, the more time it had to cool because the crystals had more time to grow
What does mineral crystal size tell about how rock formed?
The size of the crystal relates to how long the crystals were forming. For example crystals that cooled slowly are larger than those cooling faster.
How do scientists use fossils to tell them how the earth has change over millions of years of history?
They study the bones and try to figure out what animal it might have been. They can also study the rock around the fossil to tell when the rock existed and therefore when the animal was alive. They can also study the type of rock to give an idea of what the animal liked or disliked.
