A geologist discovers a sample of fine-grained rock made up of very small crystals. Based on its physical appearance, what can the geologist conclude about the rock?
Answers
Answer:
….Let’s see.. you said that the Geologist discovered Fine-grained crystals of rock, from these crystals, he has to determine the type of rock and its appearance.
Explanation:
Well, it is obvious that different types of rocks can be found as fine-grained crystals. There may also be few samples that may be in the form of rough grained crystals. In general, volcanic rocks are the types that are found naturally as fine grained crystals, as they undergo pressure. Apart from this, igneous rocks have texture that is fine, but again this factor would also depend on the time period the rock took to undergo cooling and melting process.
In case the rock undergoes slow cooling process then it forms crystals that is of large size and if the rock undergoes fast cooling process, then the crystals formed will be smaller in size.
Whereas fine grained crystals means that magma has cooled down rapidly and also that the magma was cooled nearby to the earth’s surface. You also need to keep in mind that the slow cooling or fast cooling process could yield crystals that may vary up to 1 mm in size.
Answer:
There are no options given in your answers. However, rocks that formed from magma that cooled quickly are the correct answer. According to the experiments done by geologists, it has been proved that magma cannot give the room for large or small crystal formation, but tiny and little crystals can be formed later.
For example, obsidian and volcanic rocks can form enough amounts of crystals.