Earth Sciences 1022A/B Lecture 6: Lecture 6 - Sedimentary Rocks

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Stephen R Hicock

Document Summary

Diagenesis & lithification y lithification: compaction, cementation. Detrital sedimentary rocks y mainly settled rock fragments, clay from the weathering of plutonic rocks, and quartz: shale. from settling of fine particles in quiet water. good cap rock for oil and gas. not well connected, lots of holes: sandstone. well stored if grains of similar size y sand dunes, deltas, sand bars. poorly sorted if a mix of sizes y deposited rapidly, e. g. landslide. mainly quartz grains, called arkose if it has lots of feldspar. grains it more rounded if carried by water, e. g. streams: conglomerate. from muddy gravel deposited down slopes or by currents, waves. breccia y particles deposited close to source, still angular y usually due to cave in, etc. Ions from chemical weathering precipitate in sea or ponds y y shells or organisms form biochemical sedimentary rocks y 5 main types: limestone.