11.6 Consequences for Stratigraphie Sequences
535
11.6.2 Vertical and Lateral Facies Associations Moderate clastic input
(Overview)
Low clastic input
Facies and Facies Change (General Aspects)
As described in Part 11 of this book, sediments deposited in special environments have distinct characteristics, i.e., texture, sedimentary structures, mineralogical and chemical composition, preserved remains
of their original fauna and flora, trace fossils, etc. All
these characteristics are summarized under the term
(sediment) ''facies ", which is discussed in more detail
in many textbooks (e.g. Dunbar and Rodgers 1957;
Krumbein and Sloss 1963; Blatt et al. 1980, and others). The facies of a sediment may indicate its particular depositional environment that· distinguishes it
from other facies in the same or another basin.
Changing sedimentary environments cause facies
changes both in vertical and lateral directions. One of
the basic mIes in sedimentary geology is that a special facies type can "migrate" obliquely through
space and time, whereas the facies types change both
in horizontal and vertical directions (Walter's Law,
see, e.g., Teichert 1958; textbooks mentioned above).
This means that a specific environment, producing a
certain sediment facies, is established at different
locations and times during the basin evolution.
Individual facies types are combined in characteristic vertical facies successions or, more generally, in
vertical and lateral facies associations. The principal
morphological evolution of ancient sedimentary basins can be reconstructed mainly with the aid of such
fades associations and their architectural elements
(cf. Sect. 1.4.3). Large-scale phenomena and trends
are mostly superimposed by smaller scale features
caused by relative sea-Ieve1 changes or base level
cyc1es (stacking patterns, minor sequences,
parasequences, systems or facies tracts, and rhythmic
bedding; Chap. 7). The identification and interpretation of facies associations of a basin fill are one of
the most important aims in sedimentary geology. For
this reason, the major groups of large-scale facies
associations are briefly mentioned here; smallerscale trends in the facies evolution of specific
depositional systems are described in Part IL
Vertical Facies Successions
The first two columns of facies associations demonstrate deepening environments evolving from fluvial
(bottom) to deep-sea conditions:
Abyssal plain
Deep-sea fan
Shallow marine
c1astics
Delta and lake
sediments
Braidplain
Alluvial fan
Deep-sea pelagic
sediments
Deeper marine
hemipel. sediments
Shallow marine
(below wave base)
Coastal-marine
(above wave base)
Delta, lagoon,
tidal flats
Alluvial plain
The examples of shallowing environments display
either silicic1astic or carbonate-dominated systems
and begin with deep-sea conditions (bottom of column):
Siliciclastic
sediments
Fluvial plain
Delta plain, lake,
marsh
Coastal, tidallagoonal
River mouth bar
sands
Prodelta, c1astic
shelf
Deep-sea fan
Basin plain
Carbonate sediments
Alluvial plain
(red beds)
Coastal sabkha
Carbonate lagoon,
evaporites
Reef and reef
detritus
Deeper carbonate
platform
Carbonate slope
Slope apron
carbonates
Deep-sea carbonate
Frequently, only part of these successions is realized
in a particular basin (cf. Part 11, e.g. Figs. 2.13 and
2.14, 2.28b, 3.15, 3.28a,b, 3.34 and 3.35, 4.6, 6.5e
and 6.9).
Minor vertical facies associations inc1ude:
- Pelagic to hemipelagic shales, marls, limes tones,
and black shales (cf. Sect. 7.9.3).
- Pe1agic carbonates, carbonaceous siliceous shales
and chert, red shales, mostly associated with oceanic
cmst (cf. Sect. 5.3, Figs. 5.4 and 5.5).
- Skeletal lag deposits, consisting of cephalopods,
crinoids, gastropods, etc., phosphorites, glauconitic
minerals, cmsts and nodules of iron and mangane se
oxyhydrates (condensed sections).
- Red and green shales and various evaporites (cf.
Sect. 6.4).
535
11.6.2 Vertical and Lateral Facies Associations Moderate clastic input
(Overview)
Low clastic input
Facies and Facies Change (General Aspects)
As described in Part 11 of this book, sediments deposited in special environments have distinct characteristics, i.e., texture, sedimentary structures, mineralogical and chemical composition, preserved remains
of their original fauna and flora, trace fossils, etc. All
these characteristics are summarized under the term
(sediment) ''facies ", which is discussed in more detail
in many textbooks (e.g. Dunbar and Rodgers 1957;
Krumbein and Sloss 1963; Blatt et al. 1980, and others). The facies of a sediment may indicate its particular depositional environment that· distinguishes it
from other facies in the same or another basin.
Changing sedimentary environments cause facies
changes both in vertical and lateral directions. One of
the basic mIes in sedimentary geology is that a special facies type can "migrate" obliquely through
space and time, whereas the facies types change both
in horizontal and vertical directions (Walter's Law,
see, e.g., Teichert 1958; textbooks mentioned above).
This means that a specific environment, producing a
certain sediment facies, is established at different
locations and times during the basin evolution.
Individual facies types are combined in characteristic vertical facies successions or, more generally, in
vertical and lateral facies associations. The principal
morphological evolution of ancient sedimentary basins can be reconstructed mainly with the aid of such
fades associations and their architectural elements
(cf. Sect. 1.4.3). Large-scale phenomena and trends
are mostly superimposed by smaller scale features
caused by relative sea-Ieve1 changes or base level
cyc1es (stacking patterns, minor sequences,
parasequences, systems or facies tracts, and rhythmic
bedding; Chap. 7). The identification and interpretation of facies associations of a basin fill are one of
the most important aims in sedimentary geology. For
this reason, the major groups of large-scale facies
associations are briefly mentioned here; smallerscale trends in the facies evolution of specific
depositional systems are described in Part IL
Vertical Facies Successions
The first two columns of facies associations demonstrate deepening environments evolving from fluvial
(bottom) to deep-sea conditions:
Abyssal plain
Deep-sea fan
Shallow marine
c1astics
Delta and lake
sediments
Braidplain
Alluvial fan
Deep-sea pelagic
sediments
Deeper marine
hemipel. sediments
Shallow marine
(below wave base)
Coastal-marine
(above wave base)
Delta, lagoon,
tidal flats
Alluvial plain
The examples of shallowing environments display
either silicic1astic or carbonate-dominated systems
and begin with deep-sea conditions (bottom of column):
Siliciclastic
sediments
Fluvial plain
Delta plain, lake,
marsh
Coastal, tidallagoonal
River mouth bar
sands
Prodelta, c1astic
shelf
Deep-sea fan
Basin plain
Carbonate sediments
Alluvial plain
(red beds)
Coastal sabkha
Carbonate lagoon,
evaporites
Reef and reef
detritus
Deeper carbonate
platform
Carbonate slope
Slope apron
carbonates
Deep-sea carbonate
Frequently, only part of these successions is realized
in a particular basin (cf. Part 11, e.g. Figs. 2.13 and
2.14, 2.28b, 3.15, 3.28a,b, 3.34 and 3.35, 4.6, 6.5e
and 6.9).
Minor vertical facies associations inc1ude:
- Pelagic to hemipelagic shales, marls, limes tones,
and black shales (cf. Sect. 7.9.3).
- Pe1agic carbonates, carbonaceous siliceous shales
and chert, red shales, mostly associated with oceanic
cmst (cf. Sect. 5.3, Figs. 5.4 and 5.5).
- Skeletal lag deposits, consisting of cephalopods,
crinoids, gastropods, etc., phosphorites, glauconitic
minerals, cmsts and nodules of iron and mangane se
oxyhydrates (condensed sections).
- Red and green shales and various evaporites (cf.
Sect. 6.4).