Sedimentary Rocks
3 types of sedimentary rocks
determined by how the rock forms
1. Clastic – Sediments (pieces) of other rocks
type of rock based on size of sediment
Conglomerate – rounded pebbles
Sandstone – pieces of sand grains
Shale – clay sized particles
2. Chemical – Sediments precipitate (fall out of) solution
can occur from evaporation or chemical action
Salt – evaporation
Limestone – calcite precipitates out of ocean water
3. Organic – Comes from living things
from the remains of plants and animals
Coal – fossilized plant remains
Limestone – from sea shells
Features of sedimentary rocks
1. Stratification
changes in types of sediments
2. Fossils
imprint of plants and animals in the rocks
3. Geodes
water contains minerals washes through the sediments and replaces
minerals with new minerals