The Earth’s crust is made up of rocks that are composed of various minerals. Various mineral combinations form rocks; minerals are composed of elements.
The three main types of rock found in the earth’s crust are igneous, sedimentary, and metamorphic rocks. This categorization was created by geologists depending on the tectonic processes that created these rocks.
Igneous, Sedimentary vs Metamorphic Rocks
The main difference between igneous, sedimentary, and metamorphic rocks is that they are based on their source, development, structure, categorization, etc. Igneous rocks develop when magma cools. On the other hand, precedent rock deposits form the basis of sedimentary and metamorphic rocks arising due to the change of other rocks.
Igneous rocks are formed by cooling and solidifying magma or lava that burst through the earth’s surface. The majority of these rocks are crystalline. Granite, rhyolite, and gabbro are examples of igneous rocks.
Sedimentary rocks form due to a combination and depositing of all other antecedent rocks, or microscopic fragments of the creature remains that become bonded at the base of waterways. The structure of these rocks is fragmented. Arkose, flint, and conglomerate are examples of sedimentary rocks.
Heat and pressure cause chemical and strong changes in pre-existing rocks, resulting in metamorphic rocks. The rocks are incredibly tough and have a foliated appearance. Marble, gneiss, schist, and other metamorphic rocks are examples.
Comparison Table Between Igneous, Sedimentary, and Metamorphic Rocks
| Parameters of Comparison | Igneous Rocks | Sedimentary Rocks | Metamorphic Rocks |
| Source | Igneous rocks form from molten material (magma or lava). | Sedimentary rocks are made up of antecedent rock deposits, relics, and small fragments of the animal that have survived. | Metamorphic rocks are formed through the alteration of other rocks. |
| Creation | When molten volcanic material cools and solidifies, it forms igneous rocks. | When sediments collect, settle, and solidify at the base of water bodies, sedimentary rocks occur. | Metamorphic rocks arise if other pre-existing rocks undergo physiological and biochemical changes as a result of pressure and temperature. |
| Structural design | The basic structure of igneous rocks is crystal-like. | Sedimentary rocks are fragmented and have an interior stratification known as bedding. | Metamorphic rocks are extremely hard and can be banded or layered in appearance. |
| Surface finish | The pace at which igneous rocks have cooled determines their texture. Textures ranging from coarse to glassy are provided. | Depending on compressive stress, time, and depositional environment, sedimentary rocks exhibit a variety of textures. The bulk of these seems blurry. | The foliation of rock formations is caused by pressure. Certain rocks may be banded and unfoliated. |
| Different kinds | Intrusive and extrusive igneous rocks (hardened from lava on the earth’s surface) are the two forms of igneous rocks. | Clastic, organic, and chemically created sedimentary rocks are the three kinds of sedimentary rocks. | The two main kinds of metamorphic rocks are foliated and non-foliated metamorphic rocks. |
What are Igneous Rocks?
When the molten state cools and hardens to create crystallized material, igneous rocks are formed. These rocks are referred to as ‘primary’ since they were formed from fluid (compared to high-grade sedimentary and metamorphic rocks, which were formed from pre-existing rocks).
The rocks are widespread, accounting for 95 percent of the earth’s upper crust. Furthermore, there are about 700 distinct types of these rocks. Basalt is a well-known igneous rock that is utilized in the development of most kitchen counters.
What are Sedimentary Rocks?
Sedimentary rocks are created from antecedent rocks and pieces of previously living creatures by erosion, transit, deposition, compression, and coalescence. Over millions of years, these rocks form at the base of water bodies such as oceans and rivers.
Sedimentary rocks are classified into sandstone, organic, and chemically precipitated rocks. Clastic sedimentary rocks arise due to the physical weathering of antecedent rocks.
Sustainably grown, sedimentary rocks are made of the leftovers of perished living organisms that have gathered and accumulated over time. A chemical reaction between two minerals present in rocks can occur. Whenever these minerals freeze, they precipitate, resulting in the formation of geochemical sedimentary rocks.
Sedimentary rocks include breccia, clastic, claystone, oolite, dolostone, and shale.
What are Metamorphic Rocks?
Antecedent rocks perform biochemical and physiological transformations once subjected to load and temperature swings, leading to metamorphic rocks. The rocks are exposed to heat at the top of 150 centigrade and force in larger amounts of 1,500 psi to obtain additional rocks.
Metamorphic rocks are classified into two types. Non-foliated rocks lack the thin-lined structure that foliated rocks have.
The overwhelming majority of the crust is formed from metamorphic rocks. It’s a standard quiet rock. The Taj Mahal is a massive metamorphic rock made completely of marble. Examples include greenschist, mylonite, flint, hornfels, and other metamorphic rocks.
Main Differences Between Igneous, Sedimentary, and Metamorphic Rocks
- Molten material hardens to make igneous rocks. Sedimentary and metamorphic rocks, on the other hand, are formed from pre-existing rocks.
- Igneous rocks are crystalline, sedimentary rocks are shattered and layered, and metamorphic rocks seem to be either foliated or non-foliated.
- The top portion of the earth’s crust comprises 95 percent igneous rocks, with the residual fraction comprising several different rocks and minerals.
- Compared to igneous rocks, which are found in the earth’s crust or mantle, and sedimentary rocks, which are found at the bottom of watercourses, metamorphic rock deposits are located nearer to the surface.
- Granite, the most well-known igneous rock, is used to make kitchen countertops. Sea salt is a sedimentary rock that is eaten globally. Marble and other metamorphic rocks are utilized to construct houses and buildings.
Conclusion
The genesis, structure, composition, and other characteristics of igneous, sedimentary, and metamorphic rocks may clearly distinguish them. The three types of rocks seem to be the same mineral or sediments passing throughout a rock cycle.
Weathering and cementation, for example, can transform an igneous rock into sedimentary rock. If exposed to variations in pressure and heat, this rock could further transform into a metamorphic rock.
References
- https://pubs.geoscienceworld.org/sepm/jsedres/article-abstract/33/3/559/95657
- https://www.sciencedirect.com/science/article/pii/0016714285900018
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