History of Petrology

Rocks – they are an abundant solid mass found on our planet. For thousands of years ago, rocks are already present on Earth, which prehistoric people utilize to create tools and other equipment. Years later, people continue to use rocks in different ways, including the creation of several infrastructures that we can see in our world today.

As simple as it seems, rocks are complex material that has a more sophisticated structure and usage. The utilization of rocks helped shape our modern world, and it is also a part of the development of science.

Naturally, we can find rocks in many different places, such as seabeds, mountains, and many other sites on the Earth’s crust. It is because various natural occurrences cause the formation of rocks, which take place in different areas on our planet.

These natural occurrences are what made rocks interesting, and it is also the reason why they come in various types. We might already be familiar with the three main groups of rocks, which consist of igneous rocks, metamorphic rocks, and sedimentary rocks. These groups categorize rocks based on their chemical composition, how it was formed, as well as its included minerals.

Interestingly, these factors are studied and observed by scientists who devote to the study of rocks. Because of the complexity of rocks, these scientists work under a field of Earth science called petrology – which focuses on the different types of rocks found in our world.

In this article, we are going to look into the branch of science called petrology and its history.

What is Petrology?

As mentioned earlier, petrology is the field of Earth science devoted to the study of rocks. It focuses on the different properties and condition of rocks, as well as how it was formed. Since there are three main types of rocks, petrology is subdivided into three fields of study – including igneous petrology, metamorphic petrology, and sedimentary petrology.

The study of rocks is mainly inclined with other fields of Earth science, such as mineralogy, which helps the identification of a rock’s composition and texture.

Here are the three main fields of study under petrology:

  • Igneous petrology – is a study of rocks that aims to gain an understanding of the composition and texture of igneous rocks. This type of rock includes volcanic and plutonic rocks, which means magma or molten rock is the sole basis of their formation.
  • Sedimentary petrology – apparent to its name, it devotes to the study of the composition and texture of sedimentary rocks.
  • Metamorphic petrology – is a field of science that focuses on the study of metamorphic rocks’ composition and texture. This type of rock is more complex compared to igneous and sedimentary since it is often a product of chemical, mineralogical, or textural changes caused by extreme pressure or temperature.

What is the origin of petrology?

Petrology is another branch of science that paved a long way to reach the stage that it is today. We can trace back its origins to the 19th century when the Scottish geologist Sir James Hall made an advancement in the field of Earth science.

Hall was well known for his works in the study of the Earth, mainly his experiments with basalt. He conducted various experiments, including melting and crystallization of basalt, which became an important point of discussion between other scientific beliefs.

Interestingly, the study of rocks was not yet an integral part of Earth science during the 19th century, wherein scientists mainly observe and study them in hopes of gathering information about our planet.  However, the study of rocks gradually advanced during the 20th century, wherein scientists consider it an integral part of Earth science during this time.

The development of petrology made a significant impact when the book N.L. Bowen was published in 1928. His book entitled ‘Evolution of the Igneous Rocks’ further helped the advancement of the study of rocks. It provided information about laboratory melting experiments, which built the knowledge for the diversity of igneous rocks.

Over the years, the study of rocks sparked the interest of many scientists all around the globe. Until today, petrology continues to contribute to the field of Earth science, which helps us understand more about our planet’s phenomena and origins.