GSLM - Geology, Soil, and Land Management Module Overview
Geology, Soil, and Land Management
We live on a dynamic Earth that is constantly changing above and below the surface. As we ride on giant tectonic plates that are driven by the power of nuclear decay within Earth's core, we are also exposed to the power of our Sun that drives all the surface processes. The combination of these perpetual forces creates the environment where we live and on which we depend.
Essential Questions
- What is the rock cycle?
- How are the main three types of rock formed?
- What is soil?
- How is soil formed?
- What are the causes of soil loss?
- How can grazing lands be effectively managed?
- How can overgrazing damage land?
- What causes desertification?
- What methods best limit soil erosion?
- What methods can restore soil fertility?
Key Terms
- Gully erosion- a type of erosion where significant amounts of materials are removed through channels usually due to heavy rainfall or flooding
- Rill erosion - a type of erosion where materials (sediment) are removed in small flow paths
- Salinization - accumulation of soluble salts in soil usually due to improper irrigation leading to decreased soil fertility
- Sheet erosion - a type of erosion where materials are removed in a thin layer most common with land with little vegetation
- Rock cycle - a continuous process where rocks are created, changed from one type to another, and destroyed
- Igneous- one of the three main types of rock characterized by its formation from melting and cooling
- Sedimentary- one of the three main types of rock characterized by its formation by the weathering of any exposed rock type, deposition, and cementation
- Metamorphic- one of the three main types of rock characterized by its formation by heat and pressure
- Cementation - gluing together of rocky particles doing the formation of sedimentary rock
- Waterlogging - soil condition where all pore space is filled and soil is unusable for agriculture
- Soil triangle- a graphic tool used to determine soil type by the percentage of each of the three particle types
- Pore space- the space between soil particles that can be filled with air or water
- Permeability- soil characteristic that is the measure of how easily water moves downward through it
- Silt- one of three main soil particles, the middle-sized one with a diameter of less than 0.05 and greater than 0.002 millimeters
- Sand- one of three main soil particles, the largest with a diameter from 0.005 to 2 millimeters
- Clay- one of three main soil particles, the smallest with a diameter of fewer than 0.002 millimeters
- Soil horizons- horizontal layers of soil with distinct characteristics
- Humus- the organic portion of soil composed of partially decayed plant and animal matter often the top layer.
- Desertification- the development of desert conditions in formerly fertile regions secondary to human activities like deforestation, overgrazing, and poor agricultural practices.
- Chemical weathering - the breakdown of rock through several different chemical processes, which include oxidation, carbonation, solution, hydrolysis, and hydration
- Physical weathering (or mechanical)- the breakdown of rock not due to chemical processes but physical processes such as pressure release, thermal expansion, crystal formation, and the freeze-thaw cycle
- Biological weathering- the breakdown of rock secondary to the actions or products of living organisms such as plant roots, animal activity, and production of organic acids from bacteria and fungi to animal waste.
RESOURCES IN THIS MODULE ARE OPEN EDUCATIONAL RESOURCES (OER) OR CREATED BY GAVS UNLESS OTHERWISE NOTED. SOME IMAGES USED UNDER SUBSCRIPTION.