Quiz 13- sediments Flashcards
sedimentary environment
area of sediment deposition characterized by specific climate conditions, and physical, chemical and biological processes
Continental Environments:
Lake
Alluvial
Desert
Glacial
Lake
Transport: lake current, waves
Sediments: mud, sand, saline precipitates in arid climates
Climate: Arid - Humid
Biological Processes: freshwater organisms/precipitates
Alluvial
Transport: river currents
Sediments: sand, mud, gravel
Climate: Arid - Humid
Biological Processes: organic matter in muddy flood deposits and wetlands
Desert
Transport: wind
Sediments: sand, dust
Climate: arid
Biological Processes: little biological activity
Shoreline Environments:
Delta
Beach
Tidal Flats
Delta
Transport: river currents, waves
Sediments: sand and mud
Climate: arid - humid
Biological Processes: burial of plant debris
Beach
Transport: waves, tidal currents
Sediments: sand and gravel
Climate: arid - humid
Biological Processes: little biological activity
Tidal flats
Transport: tidal currents
Sediments: sand and mud
Climate: arid - humid
Biological Processes: organisms mix sediments
Marine Environments:
Deep Sea
Continental Shelf
Organic Reefs
Continental Margin/Slope
Deep Sea
Transport: ocean currents
Sediments: mud/sand
Biological Processes: deposition of remains of organisms
Continental Shelf
Transport: waves and tides
Sediments: sand and mud
Biological Processes: deposition of remains of organisms
Organic Reefs
Transport: waves and tides
Sediments: calcified organisms
Biological Processes: secretion of carbonates by corals, etc.
Continental margin/slope
Transport: ocean currents and waves
Sediments: mud and sand
Biological Processes: deposition of remains of organisms
Diagenesis
the many physical and chemical changes that result from the increasing temperatures and pressures as they are buried ever deeper into earth’s crust
Diagenesis Steps
- sediments deposited and buried at shallow depths in Earth’s crust
- diagenesis: Cementation- minerals precipitated in the pores between sediment particles and bind them together
Compaction- decrease in volume and porosity of sediment (squeezes out water) => lithification - different sediments result in different rock from fine to coarse (ex. sand = sandstone, mud = shale, gravel = conglomerate)
Organic Matter: Diatoms = natural gas/oil, plants = coal (Heat to 90 or 120 C)
Lithification
Hardening of soft sediment into rock
Porosity
Percentage of a rock’s volume consisting of open pores between particles
Glacial
Transport: ice, meltwater
Sediments: sand, mud, gravel
Climate: cold
Biological processes: little biological activity
