Chapter 8 Flashcards
What is weathering?
The disintegration and decomposition of materials at or near the surface (can be mechanical, physical or chemical)
What is mass wasting?
The movement of a rock materials down slope under the influence of gravity (rock slides)
What is erosion?
Simultaneous weathering and transportation of sediment
What are some agents of erosion?
Water, wind, or ice
What are two types of weathering?
- Mechanical (or physical.) weathering.
- Chemical weathering.
What are the processes of mechanical weathering?
~ mineral and frost wedging: minerals, precipitate in cracks and put pressure on the rocks as they grow (freezing, and melting cycles)
~ Joints (unloading or expansion): weight of material above it is removed, and rock expands
~ thermal expansion: under intense, heat, like fires, magma, ash, rock can expand and crack
~ biological activity: plants and growing animals push rock apart and/or move it around
Definition of chemical weathering
The chemical breakup of rocks(break the bond between elements), and alters the internal structure of minerals by removing or adding elements
What are some types of chemical weathering?
Dissolution, oxidation, hydrolysis, and biological reactions
What is the definition of dissolution?
Ones are broken between the elements to create ions (charge particles) in the water. No solid particles are left.
Example: elite + carbonic acid = bicarbonate + calcium ion
True or false: hydraulic acid is natural occurring
Fast. It is only used in lab to create a stronger reaction for calcite.
What is the definition of oxidation?
Oxygen breaks the bonds with an elements containing oxygen to form new minerals (rusting)
Ex: Pyroxene + oxygen —> hematite + silica (in water)
What is the definition of hydrolysis?
Minerals like potassium felt far breakdown in the presence of water to form other products.
Ex: k-feldspar + water + hydrogen ion —> potassium ion +kaolinite + silica (in water)
What’s the definition for biological reactions?
Plants in particular undergo ion exchange via the roots, which can help chemically whether rocks
What is the definition for a differential weathering?
Rock’s weather at different rates
What type of weathering does K-feldspar undergo?
Hydrolysis
What type of weathering does biotite undergo?
Oxidation
What is the definition of regolith?
Rock and mineral fragments
What is a combination of mineral water(pieces of rock and minerals as well as organic; primarily sand, silt, and clay), water, and air- that portion of the regolith that supports the growth of plants.
Soil
True or false. Dirt is a generic name that usually refers to soil.
True
True or false. Sediment lacks organic matter.
True
What are the controls of soil formation?
- Parent material.
- Time.
- Climate.
- Plants and animals.
- Slope.
What are two types of parent material soil?
- Residual soil- parent material is bedrock
- Transported soil- parent material has been carried from elsewhere and deposited.
What is soil profile?
All of the horizons in a soil (it is like a cross session of the soil)
• soil formed processes, operate from the surface downward, but starts with rock exposed for weather
What is something that all Mature soil will have?
Horizons
What are Horizons?
Zones or layers of soil; each is designated with a letter name.
What are the horizons?
- O - organic matter
- A - topsoil
- E - zone of eluviation; zone of leaching
- B - zone of accumulation; subsoil
- C - partially weathered bedrock
- R - bedrock
What is secondary enrichment?
• concentrates metals into economical deposits.
• takes place in one of two ways:
1. Removing undesired material from the decomposing rock, leaving the desired elements behind.
- Desired elements are carried to lower zones and deposited.
What rock is an example of secondary enrichment?
Bauxite
