Interaction of Processes and Materials and the Shaping of the Geology of Minnesota

Minnesota's geology and topography reflects a dynamic Earth

• The geologic evolution of Minnesota can be understood in terms of Earth systems. A system is a group of interdependent materials that interact to form a unified whole and are influenced by related forces. Most geologic systems are open; that is, they can exchange matter and energy across their boundaries.
• Important Earth systems include rock systems, water (hydrologic) systems and plate tectonic systems.
• Systems generally involve cycles which operate as the system evolves. The rock cycle (a secnd diagram of the rock cycle (a third diagram of the rock cycle) (a fourth diagram of the rock cycle) is perhaps the most important of these cycles. You should study it now to understand the way in which geologic processes and earth materials interact to produce a dynamic Earth.
• Earth materials include minerals (the letters of the geological alphabet) and rocks (the words of the geological record).
• Earth processes can be subdivided into internal (operating in Earth's interior) and external (operating on Earth's surface).
• Internal processes are driven by heat energy from remnant and radioactive sources. We sense these processes at the surface in the form of earthquakes, volcanic activity and mountain building.
• External processes are driven by heat energy from the sun and include weathering, (another weathering site) mass wasting, erosion and deposition. Agents of erosion and deposition include running water, ground water, glaciers, waves and currents, and wind.
• Internal processes build up the Earth's surface, while external processes level the surface.
• The Earth's surface is not level, because internal and external processes struggle with one another to produce an ever-evolving geologic framework and landscape.
• The interaction between geological processes and materials has been ongoing for 4.6 billion years (the age of the Earth).
• Plate tectonics is the overriding system which controls the evolution of Earth's geologic framework. We will spend considerable time studying this important theory and you should begin your reading on this topic now.