GroWth of Present-Day Concepts, up to 1977
"In the upper Siwaliks conglomerates prevail largely; they
are often made up of coarsest shingle, precisely like that in
the beds of the great Himalayan torrents. Brown days
occur often with the conglomerate, and sometimes almost
entirely replace it. This day, eVen when tilted to the vertical
is indistinguishable in· hand specimens from that of the
recent plains depoSit; and no dOubt it was fo rmed in a
similar manner, as alluvium. The sandstone, too, of this
zone is exactly like the sand fo rming the banks of the great
rivers, but in a more or less consolidated condition."
This appeal to a specific modern analog is a good
example of an early application of actualistic principles to a sedimentological problem.
2.3 Cirowth of Present-Day Concepts,
up to 1!177
The First International Symposium on Fluvial Sedimentology was held in Calgary, in October 1977. This
event marks a watershed in the development of ideas
about fluvial sedimentary structures and facies, because it was the first time that specialists in a variety
of related areas were brought togethet to deal with
this focused theme. The publication that resulted
(Miall 1978a) is the only memoir produced by the
Canadian Society of Petroleum Geologists that has
ever been reprinted as a result of demand. This section deals 'with developments up to that time, and is
adapted from a review prepared for publication in
the proceedings volume (Miall 1978b).
2.3.1 Increasing Specialization
of the Twentieth Century
Until the end of the nineteenth century, it was possible to be both a general geologist and a geomorphologist. Middleton (1978) regarded Walther
(1893-1894) as the first ''to draw together the many
scattered observations on modern sediments and to
document the actualistk method as the basis for a
specific science of sedimentary rocks)). At about this
time, several separate themes gradually began to
appear in the study of rivers, fluvial processes,
and their deposits, Each theme became a specialized
subject, with its own body of workers, its own
purposes and applications and, eventually, its own
literature. To bridge these divergences has become an increasingly difficult objective for modern
research workers. Likewise it is a complex task
to trace the various threads that lead to our
present understanding of fluvial deposits. The fol13
lowing are the most important areas of Specialized study that were actively evolving into the late
1970s.
I. Descriptive fluvial geomorphology: the physical
characteristics of rivers, alluvial fans, floodplains,
their evolution and their variations from source
to mouth.
2. Quantitative fluvial geomorphology: the interrelationships between width, depth, slope, discharge, sinuosity, and sediment load (hydraulic
geometry).
3. Sediment transport studies: investigations of
sediment entrainment, transport rates, and
downstream textural changes.
4. Bedforms: their external form and internal structure, and their relationship to depth, velocity,
sediment grain size, and other parameters. Orientation studies, in the fotm of paleocurrent analysis.
5. Facies studies: recognition of the various discrete
lithologic components of a fluvial deposit, with
their associated sedimentary structures, and investigation of the vertical (cyclic) and lateral relationships between them. Generalizations · in the
fotm of facies models.
6. Paleohydraulics: attempts to construct quantitative descriptions of vanished rivers from evidence
contained in their deposits. This area of study is
the most recent of the six, and draws on all the
other facets of the science of fluviology listed
above.
In succeeding sections, an attempt will be made to
trace the most significant developments in each of
these branches of study down to the present day.
2.3.2 Descriptive Fluvial Geomorphology
Rivers- and drainage networks have been classified in
four principal ways by geologists and geomorphologists:
1. The cycle-of-erosion classification (youth, maturity, old age) of Davis (1898b, 1899).
2. The strUctural-control classification ( consequent, subsequent, obsequent, antecedent, superimposed, etc.) developed by Powell (1875) and
Davis (1898b, 1899; see also johnson 1932).
3. The morphological classification (braided, meandering, anastomosed, straight) which emerged
slowly, mainly during this century.
"In the upper Siwaliks conglomerates prevail largely; they
are often made up of coarsest shingle, precisely like that in
the beds of the great Himalayan torrents. Brown days
occur often with the conglomerate, and sometimes almost
entirely replace it. This day, eVen when tilted to the vertical
is indistinguishable in· hand specimens from that of the
recent plains depoSit; and no dOubt it was fo rmed in a
similar manner, as alluvium. The sandstone, too, of this
zone is exactly like the sand fo rming the banks of the great
rivers, but in a more or less consolidated condition."
This appeal to a specific modern analog is a good
example of an early application of actualistic principles to a sedimentological problem.
2.3 Cirowth of Present-Day Concepts,
up to 1!177
The First International Symposium on Fluvial Sedimentology was held in Calgary, in October 1977. This
event marks a watershed in the development of ideas
about fluvial sedimentary structures and facies, because it was the first time that specialists in a variety
of related areas were brought togethet to deal with
this focused theme. The publication that resulted
(Miall 1978a) is the only memoir produced by the
Canadian Society of Petroleum Geologists that has
ever been reprinted as a result of demand. This section deals 'with developments up to that time, and is
adapted from a review prepared for publication in
the proceedings volume (Miall 1978b).
2.3.1 Increasing Specialization
of the Twentieth Century
Until the end of the nineteenth century, it was possible to be both a general geologist and a geomorphologist. Middleton (1978) regarded Walther
(1893-1894) as the first ''to draw together the many
scattered observations on modern sediments and to
document the actualistk method as the basis for a
specific science of sedimentary rocks)). At about this
time, several separate themes gradually began to
appear in the study of rivers, fluvial processes,
and their deposits, Each theme became a specialized
subject, with its own body of workers, its own
purposes and applications and, eventually, its own
literature. To bridge these divergences has become an increasingly difficult objective for modern
research workers. Likewise it is a complex task
to trace the various threads that lead to our
present understanding of fluvial deposits. The fol13
lowing are the most important areas of Specialized study that were actively evolving into the late
1970s.
I. Descriptive fluvial geomorphology: the physical
characteristics of rivers, alluvial fans, floodplains,
their evolution and their variations from source
to mouth.
2. Quantitative fluvial geomorphology: the interrelationships between width, depth, slope, discharge, sinuosity, and sediment load (hydraulic
geometry).
3. Sediment transport studies: investigations of
sediment entrainment, transport rates, and
downstream textural changes.
4. Bedforms: their external form and internal structure, and their relationship to depth, velocity,
sediment grain size, and other parameters. Orientation studies, in the fotm of paleocurrent analysis.
5. Facies studies: recognition of the various discrete
lithologic components of a fluvial deposit, with
their associated sedimentary structures, and investigation of the vertical (cyclic) and lateral relationships between them. Generalizations · in the
fotm of facies models.
6. Paleohydraulics: attempts to construct quantitative descriptions of vanished rivers from evidence
contained in their deposits. This area of study is
the most recent of the six, and draws on all the
other facets of the science of fluviology listed
above.
In succeeding sections, an attempt will be made to
trace the most significant developments in each of
these branches of study down to the present day.
2.3.2 Descriptive Fluvial Geomorphology
Rivers- and drainage networks have been classified in
four principal ways by geologists and geomorphologists:
1. The cycle-of-erosion classification (youth, maturity, old age) of Davis (1898b, 1899).
2. The strUctural-control classification ( consequent, subsequent, obsequent, antecedent, superimposed, etc.) developed by Powell (1875) and
Davis (1898b, 1899; see also johnson 1932).
3. The morphological classification (braided, meandering, anastomosed, straight) which emerged
slowly, mainly during this century.