Reading Sedimentary Rocks

• The characteristics that provide info about transport and environment
  • Texture
  • Components
  • Fabric
  
• Sedimentary Rock Textures
  • Grain size
  • Grain shape
  • Sorting
  • Maturity
  • Clues about depositional environment & transport
  
• Sediment Components
  • Mineral & Rock fragments
  • Fossils
  • Clues about origin & depositional environment
  
• Sedimentary Fabric/Structures
  • Fabric as sediment is deposited
  • Moving fluids = dune forms - SCALE
  • Ripples -
  – Small-scale ridges that form in slow-moving fluids….
  • Cross-Bedding -
  – The result of the movement (by fluids) of large amounts of sand - dunes or bars
  
• Sedimentary Fabric/Structures
  • Cross-bedding = internal structure of dunes
  
• Sedimentary Fabric/Structures
  • Other Features
  • Dessication = mud cracks
  • Activities of organisms = trace fossils
  
• Assignment
  • Use Table 3.2 on p. 25 to Identify the three limestones
  • Read Ch. 4 and do questions with 4.7,4.11-4.15