Sedimentary rocks

Rubbled sedimentary rocks:

  • Formed through the distraction and crumbling of surface rocks.

 

  • Consist of grains
  • The base of classification is the size of grains
    • Psephital sediment: gravel stone, gravel
    • Psammital sediment: sand
    • Pelital sediment: aleurite, clay
  • Psephital and psammital sediments consist of mainly quartz, pelital consist of mainly clay minerals.

 

Characteristics of rubbled sediments:

  • Classification: marks the dimension range
  • Thinning, sphericity
  • Stratification
    • Rythmical stratification
    • Graded stratification
    • Cross stratification(oblique stratification)

The classification of common types of sedimentary rocks: