Sedimentary Rocks Flashcards
What conditions form sedimentary rocks?
processes that act at low temp and pressure
Where are sedimentary rocks most plentiful in the earth
The surface of the crust
what are the four main groups of sedimentary rocks?
siliciclastic, carbonate, evaporites, and coal
What is the most common type of sedimentary rocks?
Siliciclastic rock
Composition of siliciclastic rocks
fragments of silica-rich rocks and minerals
Generation of a siliciclastic rock commonly involves what three processes?
- Weathering
- Erosion, transport and deposition events
- Diagenesis
what are the products of weathering?
sediment and dissolved solids
What is physical weathering?
Action of wind, water, and other elements on the rocks(e.g., frost wedging); dominates in cold and dry settings.
what is chemical weathering?
Action of cellular and chemical processes on rocks (e.g.,
dissolution, oxidation, hydrolysis); dominates in hot and in wet settings.
Define erosion
Erosion is the removal of sediment by water or, less commonly, air or
glacier ice.
What three types of siliciclastic rock are there?
mudstone, sandstone, and conglomerate
What is competence in terms of water flow?
the strength of the flow, as measured by the largest clast it can carry
What is a good way to think of chmical stability of minerals?
Bowens reaction in reverse
define downflow fining
Downflow loss of unstable components
What is left in downflow finign after the maific and felsic minerals have been dispersed?
quartz