Test 2 (Lectures 4-8) Pt. 2 Flashcards
(53 cards)
The process of making sedimentary rocks is called…
Diagenesis
What are sediments comprised of?
Loose fragments of rocks, minerals, shell, shell fragments, or mineral crystals that precipitate out of water
Sediment is produced through
Weathering
What are the 2 different types of weathering?
- Physical
- Chemical
What are the 4 different types of physical weathering?
- Jointing
- Frost wedging
- Root wedging
- Thermal expansion
What is jointing?
Natural cracks formed in rocks due to the expansion of a rock undergoing exhumation cooling and extraction
When does exfoliation occur?
When jointing develops in layers parallel to the surface due to pressure release
What is frost wedging?
When water freezes and forces a rock apart
What is root wedging?
When roots grow and force a rock apart
What is dissolution?
When minerals dissolve in water
What are some things that physical and chemical weathering work to do?
- Increase surface area (physical)
- Dissolve minerals and cements (chemicals)
- Alter hard minerals into soft minerals (chemicals)
What is oxidation?
A reaction where an element loses an electron
What is differential weathering?
When weathering occurs faster at the edges and corners than on a flat face
What part of the crust do sedimentary rocks occur in?
They occur in the uppermost part of the crust. They cover igneous and metamorphic base rocks.
What are the four sedimentary rock classes?
- Clastic
- Biochemical
- Organic
- Chemical
What do clastic sedimentary rocks consist of?
Mineral grains, rock fragments, and cementing material
What processes are clastic sedimentary rocks created by?
- weathering (generation of
detritus via rock disintegration) - erosion (removal of grains)
- transportation (dispersal of solid particles and ions by
gravity, wind, water, and ice) - deposition (settling out of the transporting fluid)
- lithification (transformation
into solid rock)
What is lithification?
Transforms a loose sediment into a solid rock
What cement glues the loose sediments together?
Minerals
As transport distance increase, grain size …
Decreases
Grain size is a measure of
The size of fragments or grains
Clasts may be comprised of
Individual mineral grains or rock fragments
Angularity is
The degree of edge or corner smoothness
Degree of sorting increases with
Transport distance
