Lecture 16: Marine sediment classification and transport Flashcards
What are marine sediments?
Sediments are particles of organic or inorganic matter that are transported and accumulate in a loose, unconsolidated form
Where do these sediments originate from?
Erosion, weathering, activity of living organisms, volcanics, space etc.
How are marine sediments classified?
Particle size
maturity
source
composition
location
What is the scale called for determining sediments based on size?
The Wentworth scale
How does particle size affect settling rate?
Larger particles like sand settle much faster (2.5cms-1) than mini particles like clay which take ages
What is important to note about particle size?
Particle size is independent of composition
What is sediment maturity a reflection of?
Time and transport of the particles
Where are the marine sediments?
Deep Ocean = 23.1% of sediments with a mean thickness of 404m
Continental margins = 42% of sediments with a mean thickness of 3044m
How are sediments sorted from coastline to the ocean?
Coarser grain sediments are near the shore, grading to finer grains offshore
Sediments can be classified by location. What are the names for land vs sea sediments…
Neritic sediments (of the land) are found within the coastal environments
Pelagic sediments (of the sea) are found in the deep ocean
What can finding sediments in an outcrop tell you?
The grainsize can tell you about the conditions when the sediments where deposited
How can we tell how much transport sediment has experienced?
The rounder the grains and more well sorted a deposit is, the more transport it has experienced
