Although sediments in trench basins may be rich in
organic material, their oil potential is poor due to a
lack of reservoir rocks and the intense tectonic deformation. In addition the geothermal gradient will also
be lower than in other basins, at least at the time of
deposition.
Fore-arc basins form between the actual island arcs
with volcanoes, and the subduction trench. They are
not subjected to the intense tectonic deformation
which occurs in trench basins. Fore-arc basins often
transgress onto the island arcs as the belt of volcanic
activity gradually withdraws towards the continent.
These basins will contain fluvial and deltaic sediments
closest to the island arcs, then shallow marine continental shelf sediments. In the outer parts sediments are
deposited in deeper water towards the oceanic slope.
There is good potential here for organic-rich
sediments to accumulate, but the geothermal gradient
may be low despite the proximity to a volcanic island
chain, and maturation consequently slow.
Large parts of California in front of the Rocky
Mountains (Sierra Nevada) are a fore-arc basin (San
Joaquin Basin) and there are numerous oil fields here,
not least in the area around Bakersfield.
Intra-arc basins are a result of tensional tectonics in
the island arcs within an area otherwise characterised
by convergent plate movement. Here a system of faultcontrolled basins (graben) is formed. Sediments
deposited in these basins will for the most part be
immature, and volcanic material will be common.
Volcanic sandstones will often lose their primary
porosity rapidly due to unstable minerals and diagenetic transformation. The geothermal gradient is high,
but conditions for formation of source and reservoir
rocks are not very good.
Intra-arc basin sediments will frequently be
subjected to intense tectonic deformation which may
deform potential reservoirs.
Back-arc basins develop on the oceanic crust due to
seafloor spreading behind the island arcs. There is
likely to be an abundant supply of sediment from the
continent, and back-arc basins may also fill with deltaic and shallow marine sediments. Because of later
tectonic deformation, back-arc sedimentary basins are
not the most promising oil prospects.
The Jurassic and Cretaceous seaway through North
America east of the Rocky Mountains was a back-arc
basin during subduction of the Pacific plate. The area
is a good oil region but Tertiary uplift resulted in a
very strong meteoric water drive which flushed out
many of the oil fields.
8.13 Conclusions
Stratigraphy is a response to changes (movements) in
the Earth’s crust and sediment supply. Changes in the
environments and the biological production of
sediments are also important. The accommodation
space for sediments is also controlled by the rate of
compaction of the underlying sediments.
Geophysical methods, mainly seismics, are used to
map out sedimentary basins on a regional scale and also
on a small scale for detailed exploration and production.
It is also important to reconstruct the evolution of sedimentary basins though time and the changes with
respect to the sediment supply and the environment.
This must to a large extent be based on reconstruction of plate tectonic movements and basin modelling.
Further Reading
Berg, O.R. and Woolverton, D.G. 1985. Seismic Stratigraphy II.
An Integrated Approach to Hydrocarbon Exploration.
AAPG Memoir 39, 276 pp.
Brown, A.R. 1996. Interpretation of Three-dimensional Seismic
Data. AAPG Memoir 42, 424 pp.
Catuneanu, O. 2006. Principles of Sequence Stratigarphy.
Elsevier, 375 pp.
Emery, D. and Myers, K. 2009. Sequence Stratigraphy. Wiley,
304 pp.
Frish, W., Meschede, M., and Blakey, R.C. 2010. Plate Tectonics: Continental Drift and Mountain Building, Springer
Verlag, 212 pp.
Sclater, J.G. and Christie, P.A.F. 1980. Continental stretching:
an explanation of the post-mid Cretaceous subsidence of the
Central North Sea Basin. Journal of Geophysical Research,
85, 3711–3739 [Appendix A, 3730–3735].
Tearpock, D.J. and Bischke, R.E. 1991. Applied Subsurface
Geological Mapping. Prentice Hall, Englewood Cliffs, NJ,
648 pp.
Vail, P.R. et al. 1977. Seismic stratigraphy and global changes
of sea level. I. In: Payton, C.E. (ed.), Seismic Stratigraphy –
Applications to Hydrocarbon Exploration. AAPG Memoir
26, pp. 49–212.
VanWagoner, J.C. et al. 1990. Siliciclastic Sequence Stratigraphy in Well Logs, Cores and Outcrops. AAPG Methods in
Exploration Series 7, 55 pp.
Payton, C. 1977. Seismic Stratigraphy – Applications to Hydrocarbon Exploration. AAPG Memoir 26, 516 pp.
Suppe, J. 1985. Principles of Structural Geology. Prentice-Hall,
Inc., Englewood Cliffs, NJ, Chapter 1, pp. 17–24.
http://strata.geo.SC.edu
8 Seismic Stratigraphy, Sequence Stratigraphy and Basin Analysis
271
organic material, their oil potential is poor due to a
lack of reservoir rocks and the intense tectonic deformation. In addition the geothermal gradient will also
be lower than in other basins, at least at the time of
deposition.
Fore-arc basins form between the actual island arcs
with volcanoes, and the subduction trench. They are
not subjected to the intense tectonic deformation
which occurs in trench basins. Fore-arc basins often
transgress onto the island arcs as the belt of volcanic
activity gradually withdraws towards the continent.
These basins will contain fluvial and deltaic sediments
closest to the island arcs, then shallow marine continental shelf sediments. In the outer parts sediments are
deposited in deeper water towards the oceanic slope.
There is good potential here for organic-rich
sediments to accumulate, but the geothermal gradient
may be low despite the proximity to a volcanic island
chain, and maturation consequently slow.
Large parts of California in front of the Rocky
Mountains (Sierra Nevada) are a fore-arc basin (San
Joaquin Basin) and there are numerous oil fields here,
not least in the area around Bakersfield.
Intra-arc basins are a result of tensional tectonics in
the island arcs within an area otherwise characterised
by convergent plate movement. Here a system of faultcontrolled basins (graben) is formed. Sediments
deposited in these basins will for the most part be
immature, and volcanic material will be common.
Volcanic sandstones will often lose their primary
porosity rapidly due to unstable minerals and diagenetic transformation. The geothermal gradient is high,
but conditions for formation of source and reservoir
rocks are not very good.
Intra-arc basin sediments will frequently be
subjected to intense tectonic deformation which may
deform potential reservoirs.
Back-arc basins develop on the oceanic crust due to
seafloor spreading behind the island arcs. There is
likely to be an abundant supply of sediment from the
continent, and back-arc basins may also fill with deltaic and shallow marine sediments. Because of later
tectonic deformation, back-arc sedimentary basins are
not the most promising oil prospects.
The Jurassic and Cretaceous seaway through North
America east of the Rocky Mountains was a back-arc
basin during subduction of the Pacific plate. The area
is a good oil region but Tertiary uplift resulted in a
very strong meteoric water drive which flushed out
many of the oil fields.
8.13 Conclusions
Stratigraphy is a response to changes (movements) in
the Earth’s crust and sediment supply. Changes in the
environments and the biological production of
sediments are also important. The accommodation
space for sediments is also controlled by the rate of
compaction of the underlying sediments.
Geophysical methods, mainly seismics, are used to
map out sedimentary basins on a regional scale and also
on a small scale for detailed exploration and production.
It is also important to reconstruct the evolution of sedimentary basins though time and the changes with
respect to the sediment supply and the environment.
This must to a large extent be based on reconstruction of plate tectonic movements and basin modelling.
Further Reading
Berg, O.R. and Woolverton, D.G. 1985. Seismic Stratigraphy II.
An Integrated Approach to Hydrocarbon Exploration.
AAPG Memoir 39, 276 pp.
Brown, A.R. 1996. Interpretation of Three-dimensional Seismic
Data. AAPG Memoir 42, 424 pp.
Catuneanu, O. 2006. Principles of Sequence Stratigarphy.
Elsevier, 375 pp.
Emery, D. and Myers, K. 2009. Sequence Stratigraphy. Wiley,
304 pp.
Frish, W., Meschede, M., and Blakey, R.C. 2010. Plate Tectonics: Continental Drift and Mountain Building, Springer
Verlag, 212 pp.
Sclater, J.G. and Christie, P.A.F. 1980. Continental stretching:
an explanation of the post-mid Cretaceous subsidence of the
Central North Sea Basin. Journal of Geophysical Research,
85, 3711–3739 [Appendix A, 3730–3735].
Tearpock, D.J. and Bischke, R.E. 1991. Applied Subsurface
Geological Mapping. Prentice Hall, Englewood Cliffs, NJ,
648 pp.
Vail, P.R. et al. 1977. Seismic stratigraphy and global changes
of sea level. I. In: Payton, C.E. (ed.), Seismic Stratigraphy –
Applications to Hydrocarbon Exploration. AAPG Memoir
26, pp. 49–212.
VanWagoner, J.C. et al. 1990. Siliciclastic Sequence Stratigraphy in Well Logs, Cores and Outcrops. AAPG Methods in
Exploration Series 7, 55 pp.
Payton, C. 1977. Seismic Stratigraphy – Applications to Hydrocarbon Exploration. AAPG Memoir 26, 516 pp.
Suppe, J. 1985. Principles of Structural Geology. Prentice-Hall,
Inc., Englewood Cliffs, NJ, Chapter 1, pp. 17–24.
http://strata.geo.SC.edu
8 Seismic Stratigraphy, Sequence Stratigraphy and Basin Analysis
271