640
BASIN INVERSION
~~~I[[iilllffiJ~~~O~ RI ~ G I ~ NA~L~~~ ~
'\,r--J
BASIN FILL
L...,/
UPLIFT OF
HANGING WALL
b
(HALFGRABEN I
INTERNAL DEFORMATION OF
SYN-RIFT BASIN FILL
BASIN INVERS ION DUE TO OVERTHRUSTING
(ANDES, VENEZUELA)
c
SE
+ +
+ -+ +- +- +
+ + -+ + ..
+ -+ -+ + .. +
.. + + ... + +
+ + + + + + +
.. + + ... + t -+
+ + + + + + -+ -+
+- + ... ... •
•
+ + + + + CflV STA LLINE
++.+.+++++ SASE MENT
Fig. 12.46a-c, Various types of basin inversion and
resulting new sedimentary basins. b Example from
the Varisean fore land, UK. (From Corfield et aL
1996), c Neogene struetural inversion (Jurassie/early
Cretaeeous graben) in the Andes of Venezuela.
(From Co1etta et aL 1997, modified)
and-thrust belts marginal portions of the basin fill
may beeome overthrust onto the central former basin
(Fig. 12.46e). Basin inversion ereates new relief, erosion, and thus also the formation and filling of new
struetural depressions adjaeent to the former basin
(Fig. 12.46a,e),
Basin inversion has been described, e.g., by Cooper and
Williams (1989), Williams et aL (1989), Coward et aL
(1991), Giese and Jacobshagen (1991), Buchanan and Buchanan (1995),
Repeated basin inversion after long periods of rifting
took place in Africa and Arabia in relatively short time intervals, e.g. in the Santonian, the latest Maastrichtian, and
Eocene (Guiraud and Bosworth 1997). Basin inversion is
strong within the western Alps where the external massifs
represent uplifted halfgraben blocks, whereas the Alpine
foreland displays weakly inverted structures. (GilIchrist et
al. 1987).
Chapter 12 Basin Evolution and Sediments
Inversion tectonics is also known from the Variscan foreland in central Europe and the British Isles (Corfield et aL
1996). Strong inversion of former foredeeps has been observed when the direction of maximum shortening was perpendicular to the strike ofthe basins,
Basin inversion exerts a major influence on hydrocarbon
occurrences in rift basins. It modifies the thermal evolution
of the basin, maturation of organic matter, and hydrocarbon
migration, In addition, it rnay create new traps and alter the
porosity and permeability of the reservoir rocks (e.g. Landon
1994),
Basin Transitions on Convergent Margins
Basins evolving from the declining oeeanie stage to
the relie sear (suture zone) stage of the Wilson eycle,
are more diversified and eomplieated. Figure 12.47
displays the closing of an oeean basin between two
eontinental plates with a subduetion-related scenario
at the right-hand side. The terminal stage of an oeean
basin ean bring about the following basin-type transitions.
(1) Along passive margins:
- Transition from a passive-margin shelf-eontinental
slope-rise faeies assoeiation to a flysch-type assoeiation of a remnant basin (Fig. 12.45a).
- Transition from a deep remnant basin into a
shallow-marine relie basin (Fig. 12.45b).
- Transition from a epieontinental basin (often shelf
or inner shelt) to a periphera1 fore land basin, or to a
deformed shelf basin (overthrust) to a piggy-baek basin (cf. Seet. 12.6.2).
(2) Along active margins:
- Transition from a shelf and slope basin to a fore are
basin (Fig. 12.47a).
- Transition from strongly deformed sediments of an
aeeretionary wedge to undeformed slope basin sediments (Fig. 12.47a).
- Transition from a foreare basin to an intramontane
or intra-are basin (eontinental molasse, Fig. 12.4 7b).
- Transition from an extensional marine baekare basin
to a eompressional retroare basin or foredeep whieh is
overthrust by the are and filled predominantly with
eontinental molasse.
The basins associated with the late stages of eontinental eollision and the formation of fold-thrust belts both
on top of the downgoing plate and often also on the
overriding plate eommonly are narrow, shallow-marine or eontinental relie basins. Continued eompressional intraplate stress in both the fore are and backare
regions ean further modify, trans form, or invert the
still existing relie basins (e.g. Ziegler et aL 1998).
Polyphase basins may be subdivided further into
the following groups (Klein 1987):
BASIN INVERSION
~~~I[[iilllffiJ~~~O~ RI ~ G I ~ NA~L~~~ ~
'\,r--J
BASIN FILL
L...,/
UPLIFT OF
HANGING WALL
b
(HALFGRABEN I
INTERNAL DEFORMATION OF
SYN-RIFT BASIN FILL
BASIN INVERS ION DUE TO OVERTHRUSTING
(ANDES, VENEZUELA)
c
SE
+ +
+ -+ +- +- +
+ + -+ + ..
+ -+ -+ + .. +
.. + + ... + +
+ + + + + + +
.. + + ... + t -+
+ + + + + + -+ -+
+- + ... ... •
•
+ + + + + CflV STA LLINE
++.+.+++++ SASE MENT
Fig. 12.46a-c, Various types of basin inversion and
resulting new sedimentary basins. b Example from
the Varisean fore land, UK. (From Corfield et aL
1996), c Neogene struetural inversion (Jurassie/early
Cretaeeous graben) in the Andes of Venezuela.
(From Co1etta et aL 1997, modified)
and-thrust belts marginal portions of the basin fill
may beeome overthrust onto the central former basin
(Fig. 12.46e). Basin inversion ereates new relief, erosion, and thus also the formation and filling of new
struetural depressions adjaeent to the former basin
(Fig. 12.46a,e),
Basin inversion has been described, e.g., by Cooper and
Williams (1989), Williams et aL (1989), Coward et aL
(1991), Giese and Jacobshagen (1991), Buchanan and Buchanan (1995),
Repeated basin inversion after long periods of rifting
took place in Africa and Arabia in relatively short time intervals, e.g. in the Santonian, the latest Maastrichtian, and
Eocene (Guiraud and Bosworth 1997). Basin inversion is
strong within the western Alps where the external massifs
represent uplifted halfgraben blocks, whereas the Alpine
foreland displays weakly inverted structures. (GilIchrist et
al. 1987).
Chapter 12 Basin Evolution and Sediments
Inversion tectonics is also known from the Variscan foreland in central Europe and the British Isles (Corfield et aL
1996). Strong inversion of former foredeeps has been observed when the direction of maximum shortening was perpendicular to the strike ofthe basins,
Basin inversion exerts a major influence on hydrocarbon
occurrences in rift basins. It modifies the thermal evolution
of the basin, maturation of organic matter, and hydrocarbon
migration, In addition, it rnay create new traps and alter the
porosity and permeability of the reservoir rocks (e.g. Landon
1994),
Basin Transitions on Convergent Margins
Basins evolving from the declining oeeanie stage to
the relie sear (suture zone) stage of the Wilson eycle,
are more diversified and eomplieated. Figure 12.47
displays the closing of an oeean basin between two
eontinental plates with a subduetion-related scenario
at the right-hand side. The terminal stage of an oeean
basin ean bring about the following basin-type transitions.
(1) Along passive margins:
- Transition from a passive-margin shelf-eontinental
slope-rise faeies assoeiation to a flysch-type assoeiation of a remnant basin (Fig. 12.45a).
- Transition from a deep remnant basin into a
shallow-marine relie basin (Fig. 12.45b).
- Transition from a epieontinental basin (often shelf
or inner shelt) to a periphera1 fore land basin, or to a
deformed shelf basin (overthrust) to a piggy-baek basin (cf. Seet. 12.6.2).
(2) Along active margins:
- Transition from a shelf and slope basin to a fore are
basin (Fig. 12.47a).
- Transition from strongly deformed sediments of an
aeeretionary wedge to undeformed slope basin sediments (Fig. 12.47a).
- Transition from a foreare basin to an intramontane
or intra-are basin (eontinental molasse, Fig. 12.4 7b).
- Transition from an extensional marine baekare basin
to a eompressional retroare basin or foredeep whieh is
overthrust by the are and filled predominantly with
eontinental molasse.
The basins associated with the late stages of eontinental eollision and the formation of fold-thrust belts both
on top of the downgoing plate and often also on the
overriding plate eommonly are narrow, shallow-marine or eontinental relie basins. Continued eompressional intraplate stress in both the fore are and backare
regions ean further modify, trans form, or invert the
still existing relie basins (e.g. Ziegler et aL 1998).
Polyphase basins may be subdivided further into
the following groups (Klein 1987):