Geology is the study of the Earth, the materials of which it is made, the structure of those materials, and the processes acting upon them. It includes the study of organisms that have inhabited our planet. An important part of geology is the study of how Earth's materials, structures, processes and organisms have changed over time.1
Unraveling Earth's History
Geologists are like detectives for the Earth. By studying rocks, minerals, and fossils, they can decipher the complex history of our planet. The concept of "deep time"—the realization that the Earth is billions of years old—is central to geology.
One of the primary tools used by geologists is stratigraphy, the study of rock layers. By observing the order and composition of these layers, they can piece together sequences of ancient events, such as volcanic eruptions, the shifting of continents, and the rise and fall of ancient seas.
Plate Tectonics
A fundamental theory in modern geology is plate tectonics. It states that the Earth's outer shell (lithosphere) is divided into several sections, known as tectonic plates, that glide over the fluid-like mantle below. This movement is responsible for many of the Earth's major geological features and events:
- Earthquakes and Volcanoes: Most seismic and volcanic activity occurs along the boundaries where plates meet, grind against each other, or pull apart.
- Mountain Building: The collision of tectonic plates forces the Earth's crust upwards, creating massive mountain ranges like the Himalayas.
- Ocean Trenches: Deep ocean trenches form where one plate is forced underneath another in a process called subduction.
Geology not only tells us the incredible story of the Earth's past but also helps us understand natural hazards, discover essential resources like groundwater and minerals, and solve environmental problems.