Flashcards in Sedimentary Rocks Deck (33)
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?
Composition of siliciclastic rocks
fragments of silica-rich rocks and minerals
Generation of a siliciclastic rock commonly involves what three processes?
2. Erosion, transport and deposition events
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.
Erosion is the removal of sediment by water or, less commonly, air or
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?
what is the source of most silicilastic sediment on earth
What mechanism transports sediment from the shoreline to the ocean floor?
Areas of long term
transforms to rock
leading to lithification
transformation of sediment into rock
What does diagenesis involve?
1. burial in the sedimentary basin
2. increase in pressure and temp
3. compaction (decrease of pore-space volume)
What is cementation?
precipitation of crystalline minerals (“cement”) in the pore spaces
between sediment grains
The two dominant types of sedimentary rocks are
a) siliciclastic and carbonate rocks
b) evaporites and coal
c) carbonate rocks and evaporites
d) siliciclastic rocks and evaporites
The three main types of siliciclastic sediment are…
a) clay, silt and sand
b) mudstone, sandstone and conglomerate
c) clay, silt and gravel
d) mud, sand and gravel
Erosion refers to
a) in-situ breakdown of rock.
b) removal of sediment.
c) transport of sediment.
d) None of the above
Which mineral will likely weather first?
a) K felspar
Why does downflow fining occur in river systems?
a) Because flowing water is not infinitely competant
b) Because flowing water is turbulent.
c) Because flowing water erodes uplands.
d) Because flowing water deposits sediment in depressions.
___________ transport(s) most sediment to the ocean.