1. Sedimentary Rocks

2. What are they?
 3 types:
 Clastic or Terrigenous
 Biogenic
 Chemical

3. Clastic or Terrigenous
sedimentary rocks
 WEDCC
 Many depositional locations:
 Continental
 Shoreline
 Marine

4. Grain Size
Name of Particle Size Range Loose Sediment Consolidated Rock
Boulder >256 mm Gravel
Conglomerate or
Breccia (depends on
rounding)
Cobble 64 - 256 mm Gravel
Pebble 2 - 64 mm Gravel
Sand 1/16 - 2mm Sand Sandstone
Silt 1/256 - 1/16 mm Silt Siltstone
Clay <1/256 mm Clay Claystone, mudstone,
and shale

5. Texture
 Sorting- how uniform
the particle size is
 Rounding- angular to
rounded

6. Sedimentary structures
 Bedding (stratification)
 Cross-bedding
 Ripples
 Fossils

7. Biogenic sedimentary rocks
 Usually carbonate sediments
 Classified by mineral composition
 Created through biological processes
 Limited depositional location

8. Chemical sedimentary rocks
 precipitation of salts from solution
 Marine or non-marine
 Gypsum
 Halite