2007-10-15 01:08:23 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
intrusive and extrusive
Intrusive - cooled inside the earth and very slowly therefore course grained and lots of crystal growth. Granite is an example of intrusive rocks
Extrusive - cooled on top of the earth therefore cooled quickly which means that the rocks will be quite smooth and finely grained. Volcanic glass (black glass) or obsidian is an example. Lava flows are make up of extrusive type rock.
2007-10-15 02:07:12 · answer #1 · answered by Freddy 3 · 1⤊ 0⤋
There are potentially 2 answers to this question. The one I think you want is intrusive and extrusive. Intrusive rocks are coarse grained because they cooled slowly. Extrusive rocks are fine grained because they cooled rapidly.
The other answer could be mafic and felsic, with mafic being ferromagnesium rocks with high iron and magnesium minerals and felsic being rocks much higher in silica bearing minerals. I don't think this is the answer you are looking for because when talking about mineral content with igneous rock we usually include intermediate rocks as well.
2007-10-15 08:21:46 · answer #2 · answered by Lady Geologist 7 · 0⤊ 0⤋
There are two types of igneous rocks, based on rates of cooling. Volcanic rocks cool quickly, and form on the Earth’s surface around volcanoes. These are sometimes referred to as "lava rocks." Lava refers to the molten rock, or magma, which cools to make volcanic rock.
The second type of igneous rock is plutonic rock, which forms from the slow cooling of magma within the crust of the earth.
2014-07-15 00:45:39 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Intrusive and extrusive. Straight answer. Now research on it.
2007-10-15 10:08:30 · answer #4 · answered by the16th 4 · 1⤊ 0⤋