Detrital Sedimentary Rocks

Naming igneous rocks
Other compositional groups
Andesitic (or intermediate)
Ultramafic

Form from sediment (weathered products)
About 75 percent of all rock outcrops on the continents
Used to reconstruct much of Earth’s history
Clues to past environments
Provide information about sediment transport
Rocks often contain fossils

Economic importance
Coal
Petroleum and natural gas
Sources of iron and aluminum

Classifying sedimentary rocks
Two groups based on the source of the material
Detrital
Chemical

Detrital rocks
Material is solid particles
Classified by particle size
Common rocks include
Shale (most abundant)
Sandstone
Conglomerate