a certain rock samples was found in a certain place that was devastated by lahar. what would be the characteristics of the rock samples that was collected from the area?
a.silicon rich
b. might be a granite
c. has fine crystals
d. none of the above
Answers
The correct answer to this question is (a) silicon-rich.
Lahar is a pyroclastic flow of mud caused by volcanic eruptions accompanied by a sudden spell of rainfall. A Lahar carries volcanic debris with the low flood and is capable of destroying any kind of structure that stands in its way. Since the upper layer of the earth's soil is rich in silicate rocks, it is obvious that the volcanic debris in the lahar will destroy rocks which have silicon in it.
The other three options are invalid because -
Option (b) consists of granite, which itself is made from the solidification of lava on the earth's crust. So, it is impossible for volcanic debris to destroy an igneous rock like granite.
Option (c) is not valid, because the formation of crystals occurs only after molten magma gets cooled down.
In that way, option (d) is incorrect as well.
Ans) (a) silicon-rich
Option (a) is correct. Silicon rich
Explanation:
- A silicon-rich rock gets devastated with time.
- Magma or igneous rock is rich in silicon and it wears away with time due to contact with water.
- A lahar is a hot liquid that flows down the mountain and causes erosion of the silicon substances such as rocks.
- It wears away the material during its flow.