Themes of the Day:

• Limestones & Dolostones

Limestones & Dolostones

• Sea-Level Curves
• Overview of Carbonates
  • Carbonates - (CO₃)^2- - 10-15% of all sed rocks
  • Acid reaction - CaCO₃+2HCl=Ca²⁺+2Cl^-+CO₂+H₂O
  • often quite pure - only minor clays, silica as impurities - Why? Think: depositional environments
• Textures - more important for classification because of minimal chemical variability
  • chunky
  • laminated
  • lumpy
• Grain Types (allochemical particles)
  • Fossils
  • Ooids, pisoliths (concentric), oncolites (radiating)
  • Oncoliths
  • Peloids - nice stylolites, too!
  • Limeclasts
• Matrix
  • micritic
  • sparry
  • microspar
• Grain Size, Sorting, Rounding
• Insoluble Residues - chert nodules
• Classification
  • Dunham
  • Folk
  • Naming Examples