Short answer type questions
1. Which rocks are called Primary Rocks? Why?
2. How are sedimentary rocks important to us?
3. How are metamorphic rocks formed?
4. Give two characteristics of the uppermost outer solid layer of the earth.
5. Why the thickness of the earth's crust varies widely between continental masses and the ocean floor?
Answers
Answer:
Answer for 1st question see the attachment
2. answer is :- Sedimentary rocks tell us what the Earth's surface was like in the geologic past. They can contain fossils that tell us about the animals and plants or show the climate in an area. Sedimentary rocks are also important because they may contain water for drinking or oil and gas to run our cars and heat our homes.
3. answer:- Metamorphic rocks started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form. Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors. Conditions like these are found deep within the Earth or where tectonic plates meet.
4. answer is the uppermost solid layer is fertile and it consists of rock and soils and includes all the physical landforms of earth like plateaus , plains etc
5. answer is Why does the thickness of the earth's crust vary widely between the continental masses and the ocean floor?
Recommended by National Health Academy.
Our earths crust is devided into continental crust and oceanic crust. the continental crust is rich in Si and Al.. hence called SiAl, and oceanic crust is richer in Si and magic minerals,hence called SiMa. The oceanic crust is very young and continuously generated at the mid oceanic ridges and consumed at subduction zones. Due to denser composition, the oceanic plate subducts into the asthenosphere. And Continental plate cannot (lighter composition). As subduction of oceanic plate ( contains crust and upper part of upper mantle) occur, the sediments deposited in the basin that is being closed, are acreated to huge fold mountains (continental crust) moreover the oceanic crust on descent into the asthenosphere ungergoes partial melting forming arc mountains. Hence if we see the whole scenario,
Oceanic crust —> continental crust +remelted oceanic crust. (—-> : melting and partial melting)
And the continental crust never generally gets consumed in any tectonic process. Hence the thickness of continental crust consequently increases where as oceanic crust remains thin and constant.
Explanation:
That's the answer for all question .Hope it helps pls mark me as brainliest pls!!!!
