The Rock Cycle – Our Dynamic Earth

Module code: GL1101

Module co-ordinator: Dr Marc Reichow

Earth is a dynamic planet. The constituents of its various layers are in motion and subject to continuous changes with numerous interconnected and interdependent components. Earth’s rocks are forced to change as they encounter new environments. This dynamic transition recurring through geological time forms a basic concept in geology referred to as ‘The Rock Cycle’. This concept illustrates and explains how the three main rock types - igneous, metamorphic and sedimentary - are related to each other and how processes change from one rock type to another over time.

In this module you will learn about the natural processes responsible for the formation and transformation of the three main rock types. We will start by investigating the formation of our solar system, the origin of elements and the evolution of our planet Earth over time. We will look at the internal structure of our planet, the formation of magma and parameters controlling these processes. Exposure of rocks to the atmosphere leads to weathering and formation of sedimentary rocks which in turn, like volcanic rocks, transform with increasing pressure and temperature to metamorphic rocks.

This module will provide you with a practical introduction to the rock cycle using specimens and thin sections from our extensive collection. You will be expected to contribute to practical and seminars individually and as part of a team.

(Image: Africa and Europe were once separated by an ocean, the Tethys. Over millions of years through a process called plate tectonics, these two continents were brought closer and closer together until they eventually collided and formed the mountain range that we know today as the Alps which includes mountains such as the Matterhorn. The rocks caught up in this process were heated up and subjected to high pressures and are now being eroded away by weathering processes on the Earth’s surface. Over millions of years, the grains liberated from these rocks by erosion will be compressed and turned into sedimentary rocks and the cycle will begin once more. [credit: Sarah Lee].)

Topics covered

  • Formation of the solar system, origin of elements and evolution of our planet Earth over time
  • Main processes responsible for the formation and transformation of the three principle rock types; the holistic relationship and interplay between Earth’s various layers
  • Identification of common igneous, metamorphic and sedimentary rocks