12 Basin Evolution and Sediments
12.9 Basin-Type Transitions
(Polyp hase Basins)
12.9.1 General Aspects
12.9.2 Basin-Transition Models
Passive Continental Margins
Basin Inversion
Basin Transitions on Convergent Margins
12.9.3 Examples ofPo!yphase Basins
12.9.4 Sediment Preservation Potential ofVarious
Basin Settings
12.9.5 Summary (Polyphase Basins)
12.9.1 General Aspects
The tectonic style of a sedimentary basin may change
over time, as already indicated in the previous sections. In fact, there is barely areal sedimentary basin
of some age which did not experience a kind of basin
transformation. Rift basins, for example, frequently
evolve into continental margin basins (Sects. 12.1.
and 12.2), or remnant basins (with flysch deposits)
exhibit transitions into peripheral foreland basins
(with molasse deposits; Sect. 12.6). Basins displaying such and more drastic transitions have been referred to as "polyhistory basins" (e.g., Kingston et al.
1983; Klein 1987), but the term "polyphase basins"
appears to be more appropriate. In all these cases,
earlier basin sediments are deformed by syn- or postdepositional tectonism (cf. Sect. 1.3).
The evolution of polyphase basins follows the
general principles of plate tectonics. Ocean basins
open along a rift zone, grow by accretion of new oceanic crust to form a deep ocean basin, and elose
again, when the subduction rate of oceanic crust exceeds the its spreading rate. Subduction may finally
result in a continent-continent collision (cf. Figs. 1.2
and 1.3). This life cyele of an ocean basin is called
Wilson cycle (Wilson 1965, 1968; Dewey and Bird
1970) and may last for a few hundred millions of
years. A specific region may undergo several Wilson
cyeles during its evolution. The most important
stages ofthis concept are summarized in Table 12.1.
This simplistic scheme of the Wilson cyele does not
take into account several modifications, for example:
(1) The "mature ocean" can be relatively narrow before it starts to elose again, as assumed for the Alpine
orogeny.
(2) Micro-continents and terranes (cf. Sect. 1.2) may
produce small oceanic basins of irregular shape and
various other regional complications. The evolution
of the Tethys ocean from the late Paleozoic until the
early Tertiary is an example of such complications
(e.g. Ricou 1994). The Caribbean Sea, the Mediterranean, and large regions in southern and southeastern
Asia were strongly affected by the migration and partial rotation of rnicro-continents.
(3) Strike-slip movements and wrench faulting often
playa significant role in the basin evolution related
to the stages of the Wilson cyele.
12.9.2 Basin-Transition Models
Passive Continental Margins
Figure 12.38 shows some straightforward models of
basin transitions on a passive continental margin, i.e.,
from the embryonic to the mature stages of the Wilson cyele.
The early rift stage with predorninantly continental
deposits (Sect. 12.1.3) may be followed by a
shallow-marine protogulf stage, in which tectonic
basin subsidence is still controlled by thinning continental or transitional crust (Fig. l2.45a). With the
onset of ocean spreading (b), the basin develops an
elongate central trough (as in the Red Sea) or several
individual small troughs (Gulf of Aden, Gulf of California), where hemipelagic sediments and sediments
of various gravity mass movements accumulate. Ascending basaltic magma may form dikes and sills in
these rapidly accumulating first deep-water sediments (Sects. 4.3 and 12.8.4).
In the subsequent stages (Fig. 12.45c-e), the sedimentary history of the passive margin basin is characterized by the aggradation and outbuilding of sediments on the shelf, the continental slope and rise
(Sect. 12.2). In the early stage of this evolution the
shelf tends to be narrow and its sediments largely
consist of elastic material ineluding sands. Later, frequently shales and carbonate buildups take over depending on the elimatic situation and presence and
sediment load of large rivers. The depositional area
may inelude coastal regions which in earlier stages
12.9 Basin-Type Transitions
(Polyp hase Basins)
12.9.1 General Aspects
12.9.2 Basin-Transition Models
Passive Continental Margins
Basin Inversion
Basin Transitions on Convergent Margins
12.9.3 Examples ofPo!yphase Basins
12.9.4 Sediment Preservation Potential ofVarious
Basin Settings
12.9.5 Summary (Polyphase Basins)
12.9.1 General Aspects
The tectonic style of a sedimentary basin may change
over time, as already indicated in the previous sections. In fact, there is barely areal sedimentary basin
of some age which did not experience a kind of basin
transformation. Rift basins, for example, frequently
evolve into continental margin basins (Sects. 12.1.
and 12.2), or remnant basins (with flysch deposits)
exhibit transitions into peripheral foreland basins
(with molasse deposits; Sect. 12.6). Basins displaying such and more drastic transitions have been referred to as "polyhistory basins" (e.g., Kingston et al.
1983; Klein 1987), but the term "polyphase basins"
appears to be more appropriate. In all these cases,
earlier basin sediments are deformed by syn- or postdepositional tectonism (cf. Sect. 1.3).
The evolution of polyphase basins follows the
general principles of plate tectonics. Ocean basins
open along a rift zone, grow by accretion of new oceanic crust to form a deep ocean basin, and elose
again, when the subduction rate of oceanic crust exceeds the its spreading rate. Subduction may finally
result in a continent-continent collision (cf. Figs. 1.2
and 1.3). This life cyele of an ocean basin is called
Wilson cycle (Wilson 1965, 1968; Dewey and Bird
1970) and may last for a few hundred millions of
years. A specific region may undergo several Wilson
cyeles during its evolution. The most important
stages ofthis concept are summarized in Table 12.1.
This simplistic scheme of the Wilson cyele does not
take into account several modifications, for example:
(1) The "mature ocean" can be relatively narrow before it starts to elose again, as assumed for the Alpine
orogeny.
(2) Micro-continents and terranes (cf. Sect. 1.2) may
produce small oceanic basins of irregular shape and
various other regional complications. The evolution
of the Tethys ocean from the late Paleozoic until the
early Tertiary is an example of such complications
(e.g. Ricou 1994). The Caribbean Sea, the Mediterranean, and large regions in southern and southeastern
Asia were strongly affected by the migration and partial rotation of rnicro-continents.
(3) Strike-slip movements and wrench faulting often
playa significant role in the basin evolution related
to the stages of the Wilson cyele.
12.9.2 Basin-Transition Models
Passive Continental Margins
Figure 12.38 shows some straightforward models of
basin transitions on a passive continental margin, i.e.,
from the embryonic to the mature stages of the Wilson cyele.
The early rift stage with predorninantly continental
deposits (Sect. 12.1.3) may be followed by a
shallow-marine protogulf stage, in which tectonic
basin subsidence is still controlled by thinning continental or transitional crust (Fig. l2.45a). With the
onset of ocean spreading (b), the basin develops an
elongate central trough (as in the Red Sea) or several
individual small troughs (Gulf of Aden, Gulf of California), where hemipelagic sediments and sediments
of various gravity mass movements accumulate. Ascending basaltic magma may form dikes and sills in
these rapidly accumulating first deep-water sediments (Sects. 4.3 and 12.8.4).
In the subsequent stages (Fig. 12.45c-e), the sedimentary history of the passive margin basin is characterized by the aggradation and outbuilding of sediments on the shelf, the continental slope and rise
(Sect. 12.2). In the early stage of this evolution the
shelf tends to be narrow and its sediments largely
consist of elastic material ineluding sands. Later, frequently shales and carbonate buildups take over depending on the elimatic situation and presence and
sediment load of large rivers. The depositional area
may inelude coastal regions which in earlier stages