Ohio Resource Center

Physical Geology

Course Overview

This course (designed for grade 11 or 12) builds on the content learned through the Introduction to Earth and Space Sciences course and further develops students’ understanding of the Earth processes that operate within, at, or near the Earth’s surface. Within the course, there are three main themes from which to develop standards-based learning cycle lessons:

  • The universe
  • Earth’s dynamic systems
  • Earth’s resources

Here is an overview of each organizing theme, listing some of the key concepts that should be addressed.

The Universe

  • Space is mostly a vacuum. However, space also contains gases, dust, particles, planetoids, asteroids, and electromagnetic radiation. Space contains the universe.
  • The universe is vast, and is estimated to be almost 14 billion years old. Currently, astronomers conclude that the universe was created from a cataclysmal event referred to as the big bang. Evidence for the big bang includes cosmic background radiation and redshifts observed in the light from very distant galaxies.
  • During the big bang, all of the beginning particles of the universe were propelled outward from a single source. Large gas clouds collapsed upon themselves to form galaxies. The universe now consists of billions of galaxies, and these galaxies change over time through collisions and mergers.
  • The sun is a middle-aged, medium-sized, yellow star that formed from condensed gas. The solar system was formed from the remnants of the sun's formation. As the sun became more massive, small dust particles began to revolve around this mass. These particles, themselves, then became more massive—to eventually become planets.
  • The laws of matter apply across distance and time. Through laboratory experiments and observations of certain phenomena, scientists have determined that the motion of the Earth, the sun, and all celestial bodies is governed by gravity and inertia. This results in the rotation and revolution of everything—from the smallest asteroid to the largest black hole.

Earth’s Dynamic Systems

  • The Earth system is composed of interacting spheres: the biosphere, the atmosphere, the lithosphere, and the hydrosphere. These spheres regulate Earth’s climate and result in the dynamic nature and appearance of Earth’s surface. The sun is the major external source of energy that drives most of the interactions found among Earth’s systems.
  • The lithosphere includes all minerals, rocks and soil on earth. Minerals are naturally occurring inorganic, solid, elements and compounds. Rocks are composed of a mixture of minerals. Soil is composed of weathered rock and/or minerals and organic material.
  • Rocks are generally classified by their origin, texture, and mineral content.
  • The hydroshpere consists of all of Earth''s water (groundwater and surface water). Water can occur as a solid, liquid, and gas. Water within the lithosphere can lower the melting point of rocks, increase levels of volcanic activity, and contribute to an environment that supports plate tectonics. Water can also allow for chemical and mechanical (physical) weathering of rock, leading to the formation of soils and sediment.
  • The atmosphere is primarily composed of nitrogen, oxygen, and argon. Other gases in smaller amounts, such as greenhouse gases, are also present. The gases form a thin layer above the surface of Earth that is held in place by gravity. The atmosphere extends approximately 600 kilometers above Earth's surface.
  • The interactions between the lithosphere, the atmosphere, the hydrosphere, and the biosphere contribute to biogeochemical cycles. For example, the carbon cycle involves fossil fuels and carbonate rocks in the lithosphere, carbon dioxide and carbonic acid in the atmosphere, carbon dioxide in the hydrosphere (most notably in the ocean), and photosynthesis and respiration in the biosphere.

Earth’s Resources

  • The Earth contains a finite amount of energy and resources. With a human population of more than six billion people, it is increasingly evident that humans have the ability to positively or negatively impact Earth’s climate, atmosphere, and living systems.
  • Global climate is influenced by human interaction and planetary resources. The depletion of the ozone layer is one example. Primary and secondary air pollution has resulted in historical changes in greenhouse gas amounts in the atmosphere, creating a warming trend in global climate.
  • Conservation of resources through recycling, reduction in use, reuse, and reclamation is necessary to ensure the future habitability of Earth.