2. Student Concept Map

3. Sedimentary Rocks Dr. David Steer

4. Rock Cycle

5. Group discussion time  Given:  Bag of sedimentary rocks Group these rocks in some manner.

6. Grouping items  Remember this exercise?

7. Grouping items  Group these objects in some logical way.

8. Grouping items  Group these objects in some logical way. Hit with a stick Use only hands Kick Throw Target Depositional setting (3) Texture

9. Sedimentary Rocks: Deposition  Clastic (detrital) sedimentary rocks –  composed of sediments, rock and mineral fragments formed when rocks disintegrate at or near the earth's surface.  Chemical sedimentary rocks  precipitated from a solution (e.g. sea-water) as the result of changing physical conditions (e.g. evaporation).  Biochemical sedimentary rocks –  formed by the actions of living organisms or composed of the remains of dead organisms.

10. Clastic or Detrital Sedimentary Rocks  Clastic sediments Classified based on:  coarse grain size particles  (gravel, includes pebbles, cobbles and boulders),  medium grain size  (sand)  fine grain size  (silt) gritty feel of sample  very fine sediment  (clay) too fine to see May appear layered

11. Clastic Rocks Classified SedimentGrain Size (diameter) Sedimentary Rocks Clay less than 0.0039 mm Shale, Mudstone Silt 0.0039 to 0.0625 mm Siltstone Sand 0.0625 to 2 mm Sandstone Gravel more than 2 mm Conglomerate

12. Review  Which rock is most likely sedimentary? Temperature when formed A B C D E Depth

13. Examples of clastic sedimentary rocks  Mudstone  Fine grained low energy  Sandstone  Medium grained moderate energy  Individual grains visible in samples  Conglomerate  Medium to coarse grained high energy

14. Chemical Sedimentary Rocks  Chemical sedimentary rocks –  precipitated from a solution (e.g. sea-water) as a result of changing physical conditions (e.g. evaporation).  May be difficult to see layers  Biochemical sedimentary rocks –  formed by the actions of living organisms or composed of the remains of dead organisms.  Fossils usually apparent

15. Examples of Biochemical Sedimentary Rocks  Limestones  form when marine organisms die and their skeletons accumulate.  Coal  forms when land plants die and their organic tissue accumulate.

16. Concept Map  Construct a concept map that guides you through classifying a sedimentary rock. Classify these rocks.