Plate- Tectonic Setting of Alluvial Basins
the Jurassic Kayenta Formation of the Colorado
Plateau region. During the Namurian-Stephanian
period northern Britain underwent crustal extension behind the north-dipping Variscan subduction zone (Leeder 1982; Besly and Kelling 1988;
Coward 1990), resulting in the development of a
series of graben and half-graben basins. Initially, in
the Dinantian, these filled with carbonates and
basin-margin fan deposits. Later, during the mid
to Late Carboniferous post-rift phase, regional subsidence led to the development of a broad basin
occupying much of northern Britain, and this
filled with thick clastic deposits derived from the
hinterland, to the north (Besly and Kelling 1988;
Fraser and Ga'Wthorpe 1990; Leeder and Hardman
1990). These include important coal-bearing deltaic
deposits (the British "Coal Measures"), delta-top fluvial systems, and prodelta turbidites (Figs. 11.53,
11.54).
The Lower Jurassic Kayenta Formation of the
Colorado Plateau area developed in the backarc region between the Sierra Nevada arc and the Ancestral Rocky Mountains of the continental interior
(Middleton and Blakey 1983; Luttrell 1993). Again,
the hinterland constituted a major sediment source.
Braided fluvial systems drained southwestvv ard
from t..l-li s source area into an arid basin center, the
Utah-Idaho Trough, which filled partly with eolian
sands (Fig. 11.55). Ordovician fluvial-deltaic systems in North Wales constitute a third ancient example of an ancient partly nonmarine backarc
system (Orton 1988).
There are many Cenozoic to Recent examples of
backarc basins in Indonesia and the Philippines. For
example, Cagayan Basin on Luzon, in the Philippines
(Mathisen and Vondra 1983). In this basin, 900 m
of nonmarine volcaniclastic sediment accumulated
during the Plio-Pleistocene. The basin deepened and
widened during sedimentation as a result of increasing relief of the arc and extensional faulting in the
basin. Sedimentary styles are similar to those occurring in the nonmarine aprons of some forearc
basins, such as in Guatemala. Other examples include the Meervlakte, Sepik, and Ramu basins
of northern New Guinea, which contain thick Miocene to Recent fluvial, peat-bearing successions
(Hamilton 1979). The Pannonian Basin of the
Carpathian region in southeast Europe is another
example of a backarc basin floored by continental
crust, although Burchfiel and Royden (1982) and
Royden et a!. (1983) showed that microplate collision and strike-slip faulting complicated the history
of basin development.
387
A particularly well-studied example of a backarc
basin on continental crust is the Basin and Range
province of the western United States and northern
Mexico (Fig. 11.49). This area consists of a series of
tilted fault blocks and half-graben basins filled with
up to 3 km of nonmarine upper Cenozoic sediment.
Fault-generated relief between uplifted blocks and
the basement floor of the basins is 2-5 km, and the
entire area has been elevated by 2-3 km (Stewart
1978) and extended to at least double its original
width (Hamilton 1987). The province is characterized by an anomalously thin crust and high heat
flow. It contains abundant early Cenozoic calc-alkaline and silicic volcanics, whereas younger volcanics
are bimodal, including the voluminous Columbia
Plateau basalts, of Miocene age. Rifting began locally
in the Eocene, but the main phase of active extension
and basin subsidence did not commence until the
mid to late Miocene.
Songliao Basin, China, may be interpreted as a
backarc basin. Klimetz (1983) interpreted the basin
as a backarc rift, but Burke and Sengor (1986) suggested that the basin may be the product of "escape
tectonics" during convergence between Asia and a
North China block (basin type 4.3).
11.4.3.3 Retroarc (Foreland) Basins
Foreland basins occur in three plate-tectonic settings (Miall 1995b ). One class of basins, termed
retroarc basins by Dickinson (1974), occurs behind
(on the continental side of) compressional arcs.
Hamilton (1985) attributed crustal thickening and
subsidence in compressional arcs "to the gravitational rise and spread of batholithic plutons."
Crustal shortening, in the form of fold-thrust development, also occurs in compressional arcs (Jordan
1995). The second and third classes of foreland basin
result from collision and suturing, including arc-arc,
arc-continent, and continent-continent collision,
and are described in Sect. 11.4.5. Some sedimentary
and tectonic features common to all classes of
foreland basin are described in Sect. 11.4.6.
Examples of retroarc basins with significant
nonmarine fills occur throughout the length of the
Cordilleran-Andean ranges of the east Pacific continental margin. They include the Sevier Basin of Utah
and Idaho (Jordan 1981; Cross 1986) and many
Andean basins (Jordan 1995), such as the Llanos
Orientales and Putumayo basins of Columbia
(Salazar 1990; Stabler 1990), the Marafi6n and Beni
basins of Peru (Dumont and Fournier 1994), the
the Jurassic Kayenta Formation of the Colorado
Plateau region. During the Namurian-Stephanian
period northern Britain underwent crustal extension behind the north-dipping Variscan subduction zone (Leeder 1982; Besly and Kelling 1988;
Coward 1990), resulting in the development of a
series of graben and half-graben basins. Initially, in
the Dinantian, these filled with carbonates and
basin-margin fan deposits. Later, during the mid
to Late Carboniferous post-rift phase, regional subsidence led to the development of a broad basin
occupying much of northern Britain, and this
filled with thick clastic deposits derived from the
hinterland, to the north (Besly and Kelling 1988;
Fraser and Ga'Wthorpe 1990; Leeder and Hardman
1990). These include important coal-bearing deltaic
deposits (the British "Coal Measures"), delta-top fluvial systems, and prodelta turbidites (Figs. 11.53,
11.54).
The Lower Jurassic Kayenta Formation of the
Colorado Plateau area developed in the backarc region between the Sierra Nevada arc and the Ancestral Rocky Mountains of the continental interior
(Middleton and Blakey 1983; Luttrell 1993). Again,
the hinterland constituted a major sediment source.
Braided fluvial systems drained southwestvv ard
from t..l-li s source area into an arid basin center, the
Utah-Idaho Trough, which filled partly with eolian
sands (Fig. 11.55). Ordovician fluvial-deltaic systems in North Wales constitute a third ancient example of an ancient partly nonmarine backarc
system (Orton 1988).
There are many Cenozoic to Recent examples of
backarc basins in Indonesia and the Philippines. For
example, Cagayan Basin on Luzon, in the Philippines
(Mathisen and Vondra 1983). In this basin, 900 m
of nonmarine volcaniclastic sediment accumulated
during the Plio-Pleistocene. The basin deepened and
widened during sedimentation as a result of increasing relief of the arc and extensional faulting in the
basin. Sedimentary styles are similar to those occurring in the nonmarine aprons of some forearc
basins, such as in Guatemala. Other examples include the Meervlakte, Sepik, and Ramu basins
of northern New Guinea, which contain thick Miocene to Recent fluvial, peat-bearing successions
(Hamilton 1979). The Pannonian Basin of the
Carpathian region in southeast Europe is another
example of a backarc basin floored by continental
crust, although Burchfiel and Royden (1982) and
Royden et a!. (1983) showed that microplate collision and strike-slip faulting complicated the history
of basin development.
387
A particularly well-studied example of a backarc
basin on continental crust is the Basin and Range
province of the western United States and northern
Mexico (Fig. 11.49). This area consists of a series of
tilted fault blocks and half-graben basins filled with
up to 3 km of nonmarine upper Cenozoic sediment.
Fault-generated relief between uplifted blocks and
the basement floor of the basins is 2-5 km, and the
entire area has been elevated by 2-3 km (Stewart
1978) and extended to at least double its original
width (Hamilton 1987). The province is characterized by an anomalously thin crust and high heat
flow. It contains abundant early Cenozoic calc-alkaline and silicic volcanics, whereas younger volcanics
are bimodal, including the voluminous Columbia
Plateau basalts, of Miocene age. Rifting began locally
in the Eocene, but the main phase of active extension
and basin subsidence did not commence until the
mid to late Miocene.
Songliao Basin, China, may be interpreted as a
backarc basin. Klimetz (1983) interpreted the basin
as a backarc rift, but Burke and Sengor (1986) suggested that the basin may be the product of "escape
tectonics" during convergence between Asia and a
North China block (basin type 4.3).
11.4.3.3 Retroarc (Foreland) Basins
Foreland basins occur in three plate-tectonic settings (Miall 1995b ). One class of basins, termed
retroarc basins by Dickinson (1974), occurs behind
(on the continental side of) compressional arcs.
Hamilton (1985) attributed crustal thickening and
subsidence in compressional arcs "to the gravitational rise and spread of batholithic plutons."
Crustal shortening, in the form of fold-thrust development, also occurs in compressional arcs (Jordan
1995). The second and third classes of foreland basin
result from collision and suturing, including arc-arc,
arc-continent, and continent-continent collision,
and are described in Sect. 11.4.5. Some sedimentary
and tectonic features common to all classes of
foreland basin are described in Sect. 11.4.6.
Examples of retroarc basins with significant
nonmarine fills occur throughout the length of the
Cordilleran-Andean ranges of the east Pacific continental margin. They include the Sevier Basin of Utah
and Idaho (Jordan 1981; Cross 1986) and many
Andean basins (Jordan 1995), such as the Llanos
Orientales and Putumayo basins of Columbia
(Salazar 1990; Stabler 1990), the Marafi6n and Beni
basins of Peru (Dumont and Fournier 1994), the