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Grain size range in mm: _______ Percent of each Wentworth size class: clay _____

ID: 112495 • Letter: G

Question

Grain size range in mm: _______ Percent of each Wentworth size class: clay ______ tilt _______ sand _______ gravel _______ Grain sorting (circle): Poor Moderate Well Grain soundness (circle): Angular Subround Well-rounded Sediment composition (circle): Detrital Biochemical (Silicilastic) Chemical (Bioclastic) Describe how and in what environment (FIGURE 6.10) this sediment may have formed. Grain size range in mm: _______ Percent of each Wentworth size class: clay ______ tilt _______ sand _______ gravel _______ Grain sorting (circle): Poor Moderate Well Grain soundness (circle): Angular Subround Well-rounded Sediment composition (circle): Detrital (Siliciclastic) Biochemical (Bioclastic) Chemical Describe how and in what environment (FIGURE 6.10) this sediment may have formed. Grain size range in mm: _______ Percent of each Wentworth size class: clay ______ tilt _______ sand _______ gravel _______ Grain sorting (circle): Poor Moderate Well Grain sound

Explanation / Answer

Sample A

1. Grain size range in mm: Cobbles (64-256 mm) and pebble (4-64 mm)

2. Percent of each Wentworth size class: clay 0%, silt 0%, sand 0%, gravel 100%

3. Grain Sorting : Well

4. Grain Roundenss: Well rounded

5. Sediment Composition: Detrital (Siliciclastic)

7. Environment: Beaches and shores.

Sample B

1. Grain size range in mm: Granules (2-4 mm)

2. Percent of each Wentworth size class:clay 0%, silt 0%, sand 5%, gravel 95%.

3. Grain Sorting: Moderate

4. Grain Roundenss: Sub-rounded

5. Sediment Composition: Chemical

7. Environment of deposition: Continental to transitional environment

Sample C

1. Grain size range in mm: Fine sand (0.06-0.25 mm), medium sand (0.25-0.5 mm), coarse grained sand (0.5-2 mm), granules (2-4 mm)

2. Percent of each Wentworth size class: clay 5%, silt 10%, sand 80%,, gravel 5%.

3. Grain Sorting: Poor

4. Grain Roundenss: Angular

5. Sediment Composition: Biochemical (Bioclastic)

7. Environment: Marine environment