Types of Sediment

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Types of Sediment

• Sediments are lithified into sedimentary rocks.
• There are seven types of sediment
• Epiclastic or terrigenous (normal)
• Pyroclastic
• Orthochemical
• Allochemical
• Residual or pedogenic
• Cosmogenic
• Polygenetic.

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Characteristics of the Components of Sedimentary
Rocks

• Clastic components
• Mineralogy or for lithic clasts, petrography
• Grain/clast size
• Grain/clast morphology (sphericity, roundness)
• Grain/clast sorting
• Orthochemical components.
• Mineralogy, crystal size, crystal shape fabric

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Mineral Chemical Stability Series

• Most Stable quartz, zircon, tourmaline
• micro-quartz (chert chalcedony)
• Muscovite
• K-feldspar
• albite____________________________________
• plagioclase feldspars
• hornblende, biotite
• pyroxene
• olivine
• Least Stable From albite and above minerals form
  in the sedimentary environment (authigenic).

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Relative Abundance of Minerals

• Terrigenous Minerals
• Quartz 30-50, Clay minerals 25-35, Metamorphic
  rock fragments 5-15, Feldspar 5-15, Chert 1-4,
  Micas 0.1-0.4, Carbonates 0.2-0.4, Heavy
  Minerals 0.1- 1.0
• Chemical Minerals
• Carbonates 70-85, Silica 10-15, Sulphates and
  salts 2-7, Miscellaneous 2-7.

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CARBONATE ROCKS

• Deposited Loose (may not be totally clear)
• gt90 lime mud mudstone (deposited loose)
• lt90 lime mud wackestone (deposited loose)
• grain supported with muddy matrix packstone
• grain supported well sorted grainstone
• Deposited bound together during deposition
• boundstone (e.g. stromatolite)
• No depositional texture preserved.
• crystalline carbonate.

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CARBONATE STAINING

• Rocks and slides are stained using dilute acid
  and two dyes.
• Calcite is red if Fe-free, purple if Fe-rich
• Pure dolomite does not stain, Fe-dolomite stains
  blue.