Difference Between Foliation and Layering (With Table) 

The formation of rocks includes many processes, such as foliation and layering. Although, different kinds of rocks are involved in both. Each impacts several areas of rocks. Foliation and layering in sedimentary rocks influence the pattern. Besides the pattern, several factors are also apart in both. Yet, they’re considered similar due to their shared similarities. 

Foliation vs Layering

The main difference between foliation and layering is that foliation begins through pressure and combustion. Meanwhile, Layering begins through the embedding of fine and coarse deposits. Secondly, Foliation happens due to change in minerals through fire and intensity. While Layering happens due to seasonal changes. Thirdly, Foliation includes layers, whereas layering includes marks. Fourthly, foliation has platy and coarse-grained deposits, while layering has fine and coarse sediments. Lastly, Foliation happens mostly in metamorphic rock(except a few). Meanwhile, Layering occurs mostly in sedimentary rocks and igneous rocks. 

Foliation is a process that occurs in the formation of rock due to changes in minerals by pressure and combustion. And ultimately leads to formations of layers with platy and coarse-grained deposits. Moreover, it is generally happening in metamorphic rocks except a few. It ends up in repetitive layers in the specific types of rocks. 

Layering is also a process that occurs in the formation of rocks due to seasonal change. And it results in making a pattern and marks on the rocks. Additionally, it has fine and coarse deposits. Layering usually happens in sedimentary rocks and igneous rocks. They also help geologists to analyze and understand the changes over a period. 

Comparison Table Between Foliation and Layering 

Parameters of comparisonFoliation Layering 
Starting Foliation begins through pressure and combustion.Layering begins through the embedding of fine and coarse deposits. 
HappenFoliation happens due to change in minerals.Layering happens due to seasonal changes
Composition Foliation is composed of layers.Layering is composed of marks.
Texture Foliation has platy and coarse-grained deposits.Layering has fine and coarse deposits. 
In which types of rocksFoliation happens mostly in metamorphic rock(except a few) Layering happens mostly in sedimentary rocks and igneous rocks. 

What is Foliation? 

Foliation is a part of the process of formation of rocks but due to some reason, it occurs. It is an arrangement of structural features in any type of rock that leads to the parallel alignment of minerals. Additionally, it appears as a banded rock. 

Foliation generally happens in metamorphic rocks that are formed by the process called metamorphism. But, due to combustion and pressure rock undergoes transformation and results in metamorphic rock. 

In other words, foliation is defined as a pattern of layers caused by the parallel realignment of minerals. Moreover, it also depicts the arrangement of rocks. Due to pressure and fire, it results in foliation in, especially metamorphic rocks. 

And the formed layers are platy and coarse-grained deposits in texture. Moreover, it is generally happening in metamorphic rocks except a few. It ends up in repetitive layers in the specific types of rocks. 

It usually happens parallel to original bedding. It may not be related to another direction.

Foliation is mostly seen in sheet minerals, such as mica or chlorite. Although, foliated rocks are most experienced as they suffer eminent flattening, thereby resulting in platy and coarse-grained metamorphic rocks. Other than that, prominent pressure and high temperature are one of the factors. 

What is Layering? 

Layering is also a part of the process of formation of rocks. And it justifies its names as the formation of layers involves one layer of rocks over another and repeats. But over time, the layer is deposited and embedded against sedimentary rocks. 

Layering in sedimentary rock is very thin along with fine and coarse fragments or sediments. Although, it consists of marks. So, it is possible to trace soft and fossil sediment deformations mark. The layers vary a lot in terms of thickness, shape, and size as well. 

It is also a process that occurs in the formation of rocks due to seasonal change. And it results in making a pattern and marks on the rocks. 

The formation of sedimentary rocks occurs due to the deposition of materials at the earth’s surface. And the process through which sedimentary rocks are formed is sedimentation.  The particles that compose sedimentary rocks are called sediments. Coming to the formation of the basic material of sedimentary rocks, the sediments are formed by erosion and weathering from the original location and then transferred through air, water glacier, etc. 

Additionally, it has fine and coarse deposits. Layering usually happens in sedimentary rocks and igneous rocks. They also help geologists to analyze and understand the changes over a period. 

Main Differences Between Foliation and Layering 

Layering and Foliation are a part of the process of formation of rocks. Although, there’s a difference between foliation and layering. Yet, people don’t seem to tell them apart. Foliation and layering occur in different types of rocks along with different impacts on rocks. 

  1. Foliation begins through pressure and combustion. Meanwhile, Layering begins through the embedding of fine and coarse deposits. 
  2. Foliation happens due to change in minerals. While Layering happens due to seasonal changes. 
  3. Foliation is composed of layers, whereas layering is composed of marks. 
  4. Foliation has platy and coarse-grained deposits, while layering has fine and coarse deposits. 
  5. Foliation happens mostly in metamorphic rock(except a few). Meanwhile, Layering happens mostly in sedimentary rocks and igneous rocks. 

Conclusion 

Layering and foliation are two processes that occur during the creation of rocks. There is, however, a distinction between foliation and layering. People, on the other hand, don’t appear to be able to tell them differently. Varied types of rocks have diverse levels of foliation and layering, as well as different effects on rocks.

Foliation is a process that happens in the creation of rock as a result of pressure and combustion causing changes in minerals. And, in the end, layers of platy and coarse-grained deposits are formed. Furthermore, except for a few metamorphic rocks, it occurs often. It eventually settles into repeating layers in particular types of rocks.

Layering is another process that happens as a result of seasonal changes in the formation of rocks. As a result, a pattern and markings appear on the rocks. It also contains fine and coarse sediments. Layering is common in both sedimentary and igneous rocks. They also aid geologists in analyzing and comprehending changes throughout time.

References 

  1. https://www.sciencedirect.com/science/article/pii/0040195181900135
  2. https://link.springer.com/article/10.1007/s10342-011-0553-x
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