Basic Paleogeographic Models for Nonmarine Basins
Moody Stuart 1972), and the Permo-Triassic of
northwest Scotland (Steel and Wilson 1975). Ancient
marine examples are few and far between. Possibly
Cook Inlet, in the Tertiary, may have consisted of a
paleo-Susitna River flowing into an estuary, as it
does at the present day.
Model 7 is that of a transverse and longitudinal
river system which terminates in a river-dominated
delta. This includes several of the world's major
present-day alluvial basins, such as those of the
lower Danube, Po (Ori 1993; Fig. 11.85), TigrisEuphrates (Baltzer and Purser 1990), Indus, and
Mississippi. The Mississippi is an example of a river
flowing along the axis of a grabe4 or embayment
striking at a high angle to the continental margin.
Some of the best ancient examples include the Tertiary precursors of the modern rivers listed above
(e.g., Gulf Coast, basin type 1.2.2; Fisher and
McGowen 1967). Other examples include the Alpine
Lower Freshwater Molasse (basin type 4.1; Van
Houten 1981), and the Middle-Upper Devonian
Melville Island Group of Arctic Canada (basin type
4.3; Embry and Klovan 1976).
Tide-dominated deltas are most likely to occur at
the head of a bay or gulf at the terminus of a longitudinal river (model S). Good examples are the Ganges,
Irrawaddy (Fig. 11.86), and Niger (Fig. 11.87) fluvialdeltaic systems (basin types 4.1, 2.2, and 1.3, respec419
lively). Hobday and Von Brunn (1979) interpreted.
the Table Mountain Sandstone of eastern South
Africa in terms of a longitudinal river fl owing southwest to a tide-dominated delta system located near
the southern end of the continent, prior to the
breakup of Gondwana (basin type 1.3). Much of the
Cretaceous-Tertiary molasse of the Alberta basin
(basin type 4.3) was deposited with a model 8 geometry. For example, the Cadomin conglomerate was
a unit deposited by transverse alluvial fans draining
the ancestral Rocky Mountains. These fed a trunk
river flowing along strike, which probably flowed
into an interior epeiric sea through a tide-influenced
estuary or delta system (McLean 1977; McLean and
Wall 1981).
Model 9 is that of a transverse-longitudinal river
terminating in a wave-dominated delta. The best
examples of this type are the modern RhOne and
Nile, both of which flow along grabens that trend
virtually perpendicular to straight coastlines. They
are therefore open to the effect of waves oriented
around a 180' arc. Mutch (1968) described a Carboniferous example in New England.
A tenth model is not listed in Table 11.4 because it
does not fit the transverse-longitudinal drainage
pattern discussed here. This is the centripetal drainage pattern shown by some cratonic basins, such as
Lake Eyre basin (Fig. 11.88).
Moody Stuart 1972), and the Permo-Triassic of
northwest Scotland (Steel and Wilson 1975). Ancient
marine examples are few and far between. Possibly
Cook Inlet, in the Tertiary, may have consisted of a
paleo-Susitna River flowing into an estuary, as it
does at the present day.
Model 7 is that of a transverse and longitudinal
river system which terminates in a river-dominated
delta. This includes several of the world's major
present-day alluvial basins, such as those of the
lower Danube, Po (Ori 1993; Fig. 11.85), TigrisEuphrates (Baltzer and Purser 1990), Indus, and
Mississippi. The Mississippi is an example of a river
flowing along the axis of a grabe4 or embayment
striking at a high angle to the continental margin.
Some of the best ancient examples include the Tertiary precursors of the modern rivers listed above
(e.g., Gulf Coast, basin type 1.2.2; Fisher and
McGowen 1967). Other examples include the Alpine
Lower Freshwater Molasse (basin type 4.1; Van
Houten 1981), and the Middle-Upper Devonian
Melville Island Group of Arctic Canada (basin type
4.3; Embry and Klovan 1976).
Tide-dominated deltas are most likely to occur at
the head of a bay or gulf at the terminus of a longitudinal river (model S). Good examples are the Ganges,
Irrawaddy (Fig. 11.86), and Niger (Fig. 11.87) fluvialdeltaic systems (basin types 4.1, 2.2, and 1.3, respec419
lively). Hobday and Von Brunn (1979) interpreted.
the Table Mountain Sandstone of eastern South
Africa in terms of a longitudinal river fl owing southwest to a tide-dominated delta system located near
the southern end of the continent, prior to the
breakup of Gondwana (basin type 1.3). Much of the
Cretaceous-Tertiary molasse of the Alberta basin
(basin type 4.3) was deposited with a model 8 geometry. For example, the Cadomin conglomerate was
a unit deposited by transverse alluvial fans draining
the ancestral Rocky Mountains. These fed a trunk
river flowing along strike, which probably flowed
into an interior epeiric sea through a tide-influenced
estuary or delta system (McLean 1977; McLean and
Wall 1981).
Model 9 is that of a transverse-longitudinal river
terminating in a wave-dominated delta. The best
examples of this type are the modern RhOne and
Nile, both of which flow along grabens that trend
virtually perpendicular to straight coastlines. They
are therefore open to the effect of waves oriented
around a 180' arc. Mutch (1968) described a Carboniferous example in New England.
A tenth model is not listed in Table 11.4 because it
does not fit the transverse-longitudinal drainage
pattern discussed here. This is the centripetal drainage pattern shown by some cratonic basins, such as
Lake Eyre basin (Fig. 11.88).