Sedimentary Rocks Ch. 4, section 3 Objectives • Describe the origin of sedimentary rock. • Describe the three main categories of sedimentary rock. • Describe three types of sedimentary rocks. VOCAB • Weathering: Process of the breaking down of rock by the agents of wind, water, ice and gravity. • Erosion: Process where Weathered rock is carried away by wind, water or ice or gravity. • Deposition: Process when sediments settle out of the wind, water, or ice that carries it. VOCAB • Compaction: Process of pressing together of sediments under their own weight • Cementation: Process where dissolved minerals crystallize and glue particles of sediment together. Texting, Anyone?! Text language for Sedimentary: WEDCC WEDCC • • • • • W-breaks rocks into sediment E-moves sediment D-Drops sediment C-presses sediment together C-glues sediment together 3 groups of sedimentary rock • Organic rock: forms from the remains of once living plants and animals. Examples: Coral, Coal • Clastic: forms when rock fragments are pressed. Examples: Conglomerate, Sandstone • Chemical: forms solution of dissolved minerals and water (chemical process). Example: Halite Notes • Weathering agents break the rock down into sediment. • Then they carry (erode) these fragments away and deposit them. • As layers pile on top, the bottom layers get compacted together. • Dissolved minerals can act as glue to cement these layers into a rock. Notes, Cont’d • Sedimentary is classified by the way it forms. Either organic, chemical, or clastic.