Sedimentology and Paleontology Lecture 14: Introduction to Sedimentology Flashcards
Define Sediment
Sediment is made up of grains of rock. Sediment is always composed of grains, however does not always consist crystals.
What are the four components of sediment
Grains + Cement ± Matrix ± Porosity
Define Cement
Cement is what holds grains together
Define Matrix
Finer material/extremely fine sediment
Define Porosity
Void space between particles/grains
This may consist of air, water, oil or gas.
What are the three types of Sedimentary rocks
Siliclastic/Terrigenous
Biogenic/Biochemical/Organic
Chemical
Volcaniclastic
Describe the process of sedimentary rocks being created
Sediment –> deposited —> Buried —>Lithified —> sedimentary rock
Define Weathering and Erosion in a sedimentological context
Weathering = release of grains from regolith/parent rock
Erosion = The removal of sediment from the bedrock
What is the primary control on weathering
Climate is the primary control on weathering
Function of:
* Latitude
* Continental plate
arrangement
* Wind patterns
* Ocean circulation
* Rainfall
Describe and name the various climate belts
Glacial polar = low temperature
Mid-latitude temperate = moist and seasonal
Semi-arid subtropical = high temperature and low rainfall
Equatorial = high temperature and high rainfall
What are the two types of Weathering
Chemical and Mechanical
Describe Chemical weathering
The weathering of rocks via changing the chemical/molecular/ionic structure of the rock
Describe the controls of chemical weathering
- Water
- Temperature
- Vegetation
Describe Mechanical weathering
The weathering rocks via physical processes. The chemical structure of the rock does not change
e.g. freeze thaw weathering or roots of plants breaking rock apart(biological activity)
List the types of soil
Soil type is a function of:
* Bedrock
* Climate
* Vegetation
- Pedocals = arid
- Pedalfers = temperate
- Laterite/bauxite = humid tropical
