Growth of Present-Day Concepts> 1978-1988
FACIES
UNITS OF TABULAR
CROSS-STRAT IFIED
CONGLOMERATES
BEDDING AND SEDIMENTARY
STRUCTURES
MASSIVE
IMBRI CATED CLASTS
CRUDE FLAT-BEDDING
IMBRI CATED CLASTS
CO!
TABULAR CROSS-STRATIFIED
LATERAL ACCRETION UNITS
WITH SANDSTONE DRAPES
IMBRICATED CLASTS
t.ATEAAL AND VERTICAL
ACCRETI ONARY SURFAC ES
MASSIVE
COMPLEX - fILL
STRATIFIED
53
@
a
b
c
a
b
a
b
TRANSVERSE FILL
CROSS-STRAT I Fl CAT ! ON
�c
MULTI -STOREY FILL
TROUGH CROSS-STRATIFICATION
UNITS OF COARSE - FLAT OR LOW ANGLE
®
HEDIUM SANDSTONE ROSS-STR ATI FICATION.
RAP.E TI'OUr.H CROSS-STMTJFICATION
d
· =··· · .. ..... �
Fig. 2.40. The major depositional facies of the Buntsandstein, central Spain. {Ramos et al. 1986)
channel evolution in anastomosed systems (N.D.
Smith et al. 1989), leads to the influx oflarge volumes
of clastic detritus into the floodplains (e.g., D.G.
Smith and Locking 1989), and therefore prevents the
accumulation of ash-free peat deposits, which is the
prerequisite of coal formation (McCabe 1984). The
coal deposits referenced above will therefore need
reevaluation in the light of this improved understanding.
Secondly, the original facies model of D.G. Smith
and N.D. Smith (1980) overemphasized the idea of
vertical-channel aggradation, to the extent of proposing that "walls'' of channel-fill sand or gravel
could accumulate beneath an aggrading channel.
More recent studies of possible anastomosed channel systems in the ancient record (Eberth and Miall
1991; Nadon !991, 1994) indicate that this is a misconception. Present ideas about this fluvial style are
discussed in Sect. 8.2.10.
Thirdly, the anastomosed model was applied with
great enthusiasm to the interpretation of some
channelized petroleum-bearing sandstone bodies in
the subsurface, notably the Mannville Sandstones
(Cretaceous) of the Lloydminster area, Alberta
(Putnam and Oliver 1980; D.G. Smith and Putnam
1980). This interpretation was controversial, in part
because the modern analogs of the channel sandstones undergoing interpretation seemed quite in-
FACIES
UNITS OF TABULAR
CROSS-STRAT IFIED
CONGLOMERATES
BEDDING AND SEDIMENTARY
STRUCTURES
MASSIVE
IMBRI CATED CLASTS
CRUDE FLAT-BEDDING
IMBRI CATED CLASTS
CO!
TABULAR CROSS-STRATIFIED
LATERAL ACCRETION UNITS
WITH SANDSTONE DRAPES
IMBRICATED CLASTS
t.ATEAAL AND VERTICAL
ACCRETI ONARY SURFAC ES
MASSIVE
COMPLEX - fILL
STRATIFIED
53
@
a
b
c
a
b
a
b
TRANSVERSE FILL
CROSS-STRAT I Fl CAT ! ON
�c
MULTI -STOREY FILL
TROUGH CROSS-STRATIFICATION
UNITS OF COARSE - FLAT OR LOW ANGLE
®
HEDIUM SANDSTONE ROSS-STR ATI FICATION.
RAP.E TI'OUr.H CROSS-STMTJFICATION
d
· =··· · .. ..... �
Fig. 2.40. The major depositional facies of the Buntsandstein, central Spain. {Ramos et al. 1986)
channel evolution in anastomosed systems (N.D.
Smith et al. 1989), leads to the influx oflarge volumes
of clastic detritus into the floodplains (e.g., D.G.
Smith and Locking 1989), and therefore prevents the
accumulation of ash-free peat deposits, which is the
prerequisite of coal formation (McCabe 1984). The
coal deposits referenced above will therefore need
reevaluation in the light of this improved understanding.
Secondly, the original facies model of D.G. Smith
and N.D. Smith (1980) overemphasized the idea of
vertical-channel aggradation, to the extent of proposing that "walls'' of channel-fill sand or gravel
could accumulate beneath an aggrading channel.
More recent studies of possible anastomosed channel systems in the ancient record (Eberth and Miall
1991; Nadon !991, 1994) indicate that this is a misconception. Present ideas about this fluvial style are
discussed in Sect. 8.2.10.
Thirdly, the anastomosed model was applied with
great enthusiasm to the interpretation of some
channelized petroleum-bearing sandstone bodies in
the subsurface, notably the Mannville Sandstones
(Cretaceous) of the Lloydminster area, Alberta
(Putnam and Oliver 1980; D.G. Smith and Putnam
1980). This interpretation was controversial, in part
because the modern analogs of the channel sandstones undergoing interpretation seemed quite in-