Download SEDIMENTARY ROCK DESCRIPTIONS A description of rocks

SEDIMENTARY ROCK DESCRIPTIONS
A description of rocks requires organization and a check list is a useful way to start. Your
descriptions of sedimentary rocks should include the following characteristics (where applicable) and roughly
in this order. The Miscellaneous category is intended to accomodate special features not included
elsewhere on the sheet. You may adapt this approach for descriptions of igneous and metamorphic rocks.
I. Color
A. fresh
B. weathered
II. Texture
A. size
B. roundness
C. sphericity
D. sorting
E. surface textures of particles (where observable
F. orientation of particles
III. Mineral/Grain composition
A. particles/grains
B. cement
IV. Special features
A. fossils
1. type
2. abundance/% (each)
3. orientation
B. porosity/permeability
C. fracture
D. bedding characteristics
1. bed thickness
2. bed shape
3. (basal) contact relationships
E. sedimentary structures
F. degree of induration
G. weatherability [slope-forming (erodable), cliff-forming
(resistant)]
H. Other
V. Effects of weathering
A. Mechanical
B. chemical
VI. Miscellaneous
VII. Rock Name