1. Sedimentary, my dear Watson
Lab 6
Sedimentary, my dear Watson

2. Weather and Sediment
Chemical weathering – chemical decomposition or dissolution of a material (into a solution).
Physical weathering – physical decomposition of a material (into grains or clasts).

3. Weather and Sediment
Sediment – loose grains/chemical residues or rocks, minerals, plants & animals
Erosion – transport of weathered sediments

4. Sedimentary Rocks Form when: Sedimentary rocks are classified by:
Sediments collect, compact & harden:
Lithification
Mineral crystals precipitate from an aqueous solution
Sedimentary rocks are classified by:
Composition
Texture

5. Sedimentary Composition
Detrital (siliciclastic) –
Rock or mineral fragments
Quartz, feldspar, clay, or lithic fragments
Chemical –
Precipitated from aqueous solution
Calcite, dolomite, halite, gypsum, iron bearing minerals, chert
Biochemical (bioclasts) –
Grains are remains of organisms
See page 116 in lab manual

6. Sedimentary Textures Grain size: Deposits Precipitates
Gravel size > sand sized > silt sized > clay sized
Precipitates
Crystalline > microcrystalline

7. Sedimentary Textures Grain shape:
Describes the smoothness of the edges of grains
Well rounded to angular

8. Sedimentary Textures Grain arrangement: See page 111 in lab manual
Describes sorting of the grains
Poorly sorted, moderately sorted, well sorted
See page 111 in lab manual

9. Depositional environment??
Detrital?
Precipitates?
Biochemical/bioclasts?