What is geology?

Geology is the scientific study of the structure, composition, origins and history of the earth, and the processes that shape it. It provides evidence for the evolutionary history of life and past climates, and is important for understanding the natural hazards associated with plate tectonics and their impact on human populations and the environment. It also includes the study of rocks, minerals, landforms, soil and sediments, fossils, mountains and energy resources.

What do we already know about geology?

We know from radiometric dating that the Earth is about 4.5 billion years old. The history of Earth is described by the geological timescale, which is divided into eras, periods, epochs and ages; we are currently in the Holocene epoch, which began about 11,700 years ago. The structure of the Earth is made up of several layers, starting in the centre with the inner and outer cores, followed by the lower and upper mantles, and the crust. The Earth’s lithosphere, consisting of the crust and upper mantle, is separated into tectonic plates. There are three types of plate boundary: divergent, where the plates are moving away from each, creating new material, e.g. mid-ocean ridges; convergent, where one plate subsides underneath the other creating an area of volcanic and seismic activity; and conservative, where plates slide past each other resulting in large earthquakes. The theory of plate tectonics accounts for the movement of continents across the Earth’s surface over geological time, known as continental drift, and seafloor spreading. The geological history of Earth is recorded in the rocks. We know that there are three main rock types on Earth: igneous, sedimentary and metamorphic. The changes these rock types undergo as a result of heat, pressure, weathering and erosion are described by the rock cycle.

Why is it important to study geology?

Knowledge of Earth’s history and its processes is important for understanding past life, past climates and evolution and to predict future changes and their possible consequences. Understanding of natural hazards, such as earthquakes, volcanoes, floods, landslides, tsunamis and subsidence, aids in the development of safer building regulations, warning systems and evacuation procedures, which reduces the loss of the life and damage caused by these events. Geology is also important for locating areas for exploration of natural resources, such as water, fossil fuel and minerals, and determining how Earth’s limited resources can be used economically and sustainably.

What research is being done?

Geology research is as varied as the Earth itself. It encompasses research on the dating of geological events, rocks and their formation, rivers, landscapes and glaciers, current and past biogeochemical pathways, soil and sediments and their distribution, erosion, transportation and deposition, geophysics, isotope geochemistry, and the movement and evolution of tectonic plates. It also includes applications such as the exploration and exploitation of natural resources and sequestration of carbon dioxide and other geoengineering options.

How is geology studied?

Geology is studied primarily by mapping areas and carrying out surveys in the field, and collecting samples for chemical and microscopic analysis in the laboratory. Field work also includes the excavation of fossils, as Darwin did himself during his voyage on HMS Beagle, and the collection of ice and sediment cores to gain information on past climates and sea level. Computer modelling and remote sensing are also important methods for studying the the Earth’s past, present and future geology.

Where can I find out more?

British Geological Survey

US Geological Survey

The Geological Society

The geological timescale

If you want to get involved with our geology research, or any other part of the HMS Beagle Project’s science programme, please contact us.