Page 33 - Petrology of Sedimentary Rocks

TABLE I”

Terms Applied to Mixtures of Gravel, Sand, and Mud
Delimited in the triangular diagram page

Major Textural Class Examples of Usage

G. Gravel . . . . . . . . . . . . . Cobble gravel
Conglomerate . . . . . . . . . . Granule conglomerate
sG. Sandy gravel . . . . . . . . . . Sandy pebble gravel
Sandy conglomerate . . . . . . . Sandy boulder conglomerate
msG. Muddy sandy gravel . . . . . . . Muddy sandy granule gravel
Muddy sandy conglomerate . . . . Clayey sandy pebble conglomerate

mG. Muddy gravel . . . . . . . . . . Silty boulder gravel
Muddy conglomerate . . . . . . . Muddy pebble tong lomera te

6. Gravelly sand . . . . . . . . . . Pebbly coarse sand
Conglomexc sandstone . . . . . Granular very fine sandstone
gmS. Gravelly muddy sand . . . . . . . Pebbly silty fine sand
Conglomeratic muddy sandstone . . Bouldery muddy coarse sandstone

0. Gravelly mud . . . . . . . . . . Cobb ly clay
Conglomexc mudstone . . . . . Pebbly si I tstone

(g)S. Slightly gravelly sand. . . . . . . Slightly granular medium sand
Slightly conglomeratic sandstone . Slightly pebbly coarse sandstone
muddy
(gh-6. Slightly gravelly ~- sand. . . . Slightly pebbly muddy medium sand
Slightly conglomeratic muddy
sandstone . . . . . . . . . . . Slightly cobbly silty fine sandstone

(g)sM. Slightly gravelly sandy mud . . . . Slightly granular fine sandy mud
SI ight ly conglomerat ic sandy
mudstone . . . . . . . . . . . Slightly pebbly coarse sandy claystone

(g)M. Slightly gravelly mud . . . . . . . Slightly pebbly clay
Slightly conglomeratic mudstone . . Slightly cobbly mudstone
S. Sand (specify sorting). . . . . . . Well-sorted fine sand
Sandstone (specify sorting) . . . . Poorly sorted medium sandstone
mS. Muddy Sand . . . . . . . . . . . Well-sorted silty very fine sand
Muddy sandstone . . . . . . . . . Muddy coarse sandstone
SM. Sandy mud . . . . . . . . . . . Fine sandy clay
Sandy mudstone (specify structure) . Coarse sandy siltstone (if fissile,
coarse sandy si It-shale)
M. Mud . . . . . . . . . . . . . . Silt
Mudstone (specify structure). . . . Mudstone (if fissile, mud-shape)

*Both unconsolidated and consolidated equivalents are shown in this table. The
underlined terms are further specified as to their grain size, as shown in the examples.

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