sedimentary rocks Flashcards
lithification
taking sendiment and forming it into rocks
sent=diedntary rocks make up__ amt of earth’s surface
75% of earth’s surface
2 steps of the lification process
coampaction
cemintation
compaction: adding more rocks and pushing the rocks down to get it closer together, less space between the rocks
cementstion:
water adds to compaction, percipitates it, and glues it together leaving minerals behind
clastic/detrital rocks
made of preexisting rock that broke apart
chemical rocks
minerals cercipitatie out of a solution (ex calcium and calcite)
organic rocks
eg. coal
fro carbon rich organisms
clastic rock made of what?
quartz and clay minerals
if find other silicate minerals in sedimentary rock
sediment didnt travel far from source rock
it depisited very quickly
what is a mature vs immature rock?
immatrue: still lhas those silicates
mature: weathere longer so loots of quartz and elss of other silicates liek feldspar
smallest grain of sediment rocks?
what size
clay
<.004 mm
2nd smallest grain of sedimenty rock?
silt
.004-.06 mm
sand grain size?
fine sand? .06
medium sand? .25
coarse sand? .5-2mm
can sometimes id the mineral with larger grain of sand
biggest size of grains?
pebbles
what is the most common sedimentry rock?
shale
it is very brittle, forms thin layers
difference between shale and mudstone/siltstone?
simialrites?
shale has thin layers but mudstone has thick layers
s: in low energy enviorments EG, deep ocean, lakes