TyPE 
MARINE 
LAcusTRINE 
EsTUARINE 
FLUVIATILE 
CrusH 
GLACIAL 
MATRIX 
Clean sands, fairly well assorted, 
cross-stratifed, angular to 
rounded grains. 
Similar to marine; perhaps less 
well-sorted, less clean, and less 
well-rounded grains. 
Fine gravel and sand with much 
mud, unsorted, cross-stratified; 
angular to subangular grains. 
Sands mingled with finer and coarser 
material, not well sorted, cross-stra- 
tified, angular to subangular grains. 
Unsorted autoclastic fragments. 
Heterogeneous mass of finer and coarser 
material, compact, angular grains of 
minerals and rocks; some fresh feld- 
spar; some grains partially rounded 
and partially angular. 
PEBBLES 
Generally local materials, fairly 
uniform size, well rounded; 
may be scratched by shore-ice, 
landslides, etc., but not faceted 
nor snubbed. 
Similar to marine, though perhaps 
less well sorted and rounded. 
Local materials varying in size 
and not well sorted, ‘subangular 
shapes on the whole; markings 
as in marine. 
Generally local materials of all sizes up 
to masses of several tons, generally 
subangular, but varying from rounded 
to angular; fragments of one stratum 
included as pebbles in another stratum 
of same formation. May be scratched 
by river-ice action, landslides, etc., but 
not faceted nor snubbed. 
Varying size and shape, angular to 
rounded, showing portions of 
crests or limbs of folds; frac- 
ture planes; tension cracks. 
Autoclastic fragments. 
Generally local materials, but a consid- 
erable proportion from distant sources. 
Little, if any, assortment; all sizes up 
to masses of several tons. Pebbles 
faceted, rounded edges, snubbed ends, 
polished and striated surfaces, with 
striae generally parallel to long axis of 
stone, but often showing two or more 
directions. 
COLOR 
May be ferruginous, but not us- 
ually highly colored. 
Similar to marine. 
Tendency to red color( ?) 
Many not colored, but perhaps tendency 
to red color. 
Depends on parent rock. 
Generally dark grayish with bluish and 
greenish tints, occasionally ferrugi- 
nous. 
BEDDING 
Stratification generally well mark- 
ed. Cross-stratification often 
well developed; in the normal 
cycle finer sediments encroach 
upon and overlie coarser mate- 
tials; sometimes local uncon- 
formities, irregularities, lenses, 
etc., but more regular along the 
original strike than along the 
dip; limestones in the series 
composed chiefly of organic re- 
mains. 
Conforms more closely with 
marine than with fluviatile de- 
posits; in the normal cycle 
coarse materials encroach upon 
and overlie finer sediments. 
Limestones or marls of the 
series contain remains of fresh- 
water organisms. 
Frequent and irregular interbed- 
ding of coarse sands and finer 
' materials; frequent cross-strati- 
fication; ripple-marked and 
sun-cracked surfaces with or- 
ganic and other imprint mark- 
ings. 
Frequent alternation coarse and fine beds; 
frequent current markings and oblique 
lamination; frequent local unconform- 
ities; irregularities in thickness and 
character, lenses, etc., but less regular 
along the original strike than along the 
dip; limestones infrequent, but where 
they occur and are unaltered, they 
consist of amorphous carbonate of 
lime and not of organic remains. 
No true bedding, all traces of 
original bedding may have been 
destroyed. 
Till and corresponding ancient forma- 
tions, usually not bedded; sometimes 
obscure stratification, and layers when 
separated show glazed and striated 
surfaces; sometimes pockets, lenses, 
and beds of coarser and finer stratified 
material with cross-stratification in- 
cluded in the unstratified mass. 
Fluvio-glacial materials show all grada- 
tions from no stratification to well- 
marked fluviatile type. 
Marine glacial bowlder beds show well- 
marked stratification and alternation 
of coarser and finer beds. 
RELATIONS TO SUB- 
JACENT RockKS 
Conformable or unconformable; 
nothing especially distinctive of 
marine action. 
Same as marine. 
Same as marine. 
Same as marine. 
Pseudo-unconformity by over- 
thrust faulting or slickensiding. 
Rests on striated, smoothed, and polished 
surfaces of older rocks or older por- 
tions of the same formation. 
