Consider the following statements with regard to sedimentary rocks.1. ...
Sedimentary rocks do not occur in crystalline form and often contain fossils. They may be coarse or fine grained, soft or hard.
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Consider the following statements with regard to sedimentary rocks.1. ...
Sedimentary rocks are a type of rock that forms at or near the Earth's surface through the process of sedimentation. They are formed by the accumulation and consolidation of sediments, which are particles of rock, minerals, or organic material that have been transported and deposited by water, wind, ice, or gravity. Sedimentary rocks are one of the three main types of rocks, along with igneous and metamorphic rocks.
Statement 1: Sedimentary rocks are formed at Earth's surface by the hydrological system.
This statement is correct. Sedimentary rocks are primarily formed by the processes of erosion, transportation, deposition, and lithification, which are all part of the hydrological system. Water plays a significant role in the formation of sedimentary rocks by carrying and depositing sediments in various environments such as rivers, lakes, oceans, and deserts.
Statement 2: The formation of sedimentary rocks involves the weathering of pre-existing rocks.
This statement is correct. Weathering is the process by which rocks are broken down into smaller particles through physical, chemical, and biological processes. These weathered particles, called sediments, are then transported and eventually deposited to form sedimentary rocks. The type and composition of the pre-existing rocks can influence the characteristics of the sedimentary rocks formed.
Statement 3: Sedimentary rocks contain fossils and typically occur as layers in a crystalline form.
This statement is incorrect. Sedimentary rocks often contain fossils, as they are formed in environments where the preservation of organic material is possible. Fossils are the remains or traces of ancient organisms that are embedded within the sedimentary rocks. However, sedimentary rocks do not typically occur in a crystalline form. Unlike igneous rocks, which form from the cooling and solidification of molten material, sedimentary rocks are composed of fragments and particles that are cemented together.
In conclusion, the correct statements regarding sedimentary rocks are:
1. Sedimentary rocks are formed at Earth's surface by the hydrological system.
2. The formation of sedimentary rocks involves the weathering of pre-existing rocks.
Therefore, the correct answer is option A: 1 and 2.
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