Consider the following statements about rocks: 1. Igneous rocks arc a...
Sandstone is a sedimentary rock formed by sedimentation of sand grains.
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Consider the following statements about rocks: 1. Igneous rocks arc a...
Explanation:
To determine the correct statement(s) about rocks, let's analyze each statement:
Statement 1: Igneous rocks are also called primary rocks.
This statement is correct. Igneous rocks are formed from the solidification of molten material, such as lava or magma. They are considered primary rocks because they are the result of the initial solidification of molten material.
Statement 2: Igneous and sedimentary rocks can change into metamorphic rocks under great heat and pressure.
This statement is also correct. Both igneous and sedimentary rocks can undergo metamorphism, which is the process of transformation due to high temperatures and pressures. The heat and pressure cause the minerals within the rocks to recrystallize, resulting in the formation of new minerals and a change in the rock's texture and structure. This process can occur deep within the Earth's crust where rocks are subjected to extreme conditions.
Statement 3: Sandstone is a metamorphic rock.
This statement is incorrect. Sandstone is actually a sedimentary rock, not a metamorphic rock. It is composed mainly of sand-sized mineral particles or rock fragments, which have been compacted and cemented together over time. Although sandstone can sometimes undergo minor metamorphic changes, such as increased hardness or recrystallization of minerals, it does not fully transform into a metamorphic rock.
Conclusion:
Based on the analysis, we can conclude that statement 1 and statement 2 are correct, while statement 3 is incorrect. Therefore, the correct answer is option 'A' - 1 and 2 only.
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