paleozoic-mesozoic stratigraphy of oman
TRANSCRIPT
-181 Middle East Geology -Geol 501-142
Paleozoic-Mesozoic Subsurface Stratigraphy and Petroleum System of Oman
by
Abdullah [email protected]
KFUPMEarth Science Department
May 10, 2015
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Outline• Introduction.• Geological and Tectonic Settings of Oman.• Paleozoic Stratigraphy of Oman.• Paleozoic Petroleum System of Oman.• Mesozoic Stratigraphy of Oman.• Mesozoic Petroleum System of Oman.• Conclusion.
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Introduction
(Forbes, et al., 2010)
North
Central
South
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Objectives
• To summarize the geologic and tectonic settings of Oman.• To demonstrate the Paleozoic-Mesozoic subsurface stratigraphy and
Petroleum System of Oman.
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Summary of the tectonic history of Oman
• Oman was situated in a passive margin after final amalgamation of Gondwana with collision of East and West Gondwana, transpressional in character, which led to the development of extensive salt basins.
• During ‘Hercynian’ event, the collision of Gondwana and Laurasia, uplifts and erosions were happened on the eastern flank of Oman and spread to the north during the Devonian– Carboniferous, resulting in a major stratigraphic unconformity.
• By the Late Carboniferous, Oman was affected by the 3rd glacial phase of AP.
• From mid-Permian to ‘mid’-Cretaceous times, a passive margin was developed with an extensive carbonate deposition.
• The opening of the Atlantic Ocean during the Late Cretaceous led to the closure of the Neo-Tethys Ocean, obduction of Semail Ophiolite, and finally to southward thrust stacking in the Oman Mountains.
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Main Structu
ral Elemen
ts
(For
bes,
et a
l., 2
010)
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Surface Geolog
ic setting
s
(Forbes, et al., 2010)
-188 Middle East Geology -Geol 501-142(Forbes, et al., 2010)
Cross Section A-A’
Surf
ace
Geo
logi
c se
tting
s
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Surf
ace
Geo
logi
c se
tting
s
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Cross Section B-B’
Surf
ace
Geo
logi
c se
tting
s
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Pale
ozoi
c Su
bsur
face
St
ratig
raph
yDepositional
Environment
-Shallow-marine
-Muddy, Playa
-Continental
-subtidal , fluvial to shallow marine, braided delta
-Trans.-Regres. cycles open-marine
Siliciclastic, glacially-influenced
-Shallow-marine
-Braided
- Marginal marine to fluvial
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Mes
ozoi
c Su
bsur
face
St
ratig
raph
yDepositional
Environment
- marginal-marine to tidal-flat
-From lower clastic succession into a shallow-marine.
- from deep to shallow marine. -Clastics in south
-Shallow marine
-Shallow-marine
- estuarine and fluvial
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Pale
ozoi
c eq
uiva
lent
fo
rmati
ons
(PGS, 2003)
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Mes
ozoi
c eq
uiva
lent
fo
rmati
ons
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(Al-Barwani & McClay,2008)
Subs
urfa
ce
Chro
nost
ratig
raph
yReservoir
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Conclusion• Oman is distinguished by the appearing of Precambrian salt basins, and Late
Cretaceous Semail Ophiolite.
• Stratigraphers divided the whole sedimentary successions of Oman into 16 groups and 48 formations.
• Misfar Group which is the only group having no classified formations due to the lack of information.
• Omani sedimentary successions, from the infracambrian successions to the Cenozoic successions, are important in terms of petroleum system.
• The source rocks recognized in Ara Group, Sahmah formation, Shuaiba and Natih formations.
• The major hydrocarbon-bearing units in the whole Omani successions include: Ara Group, Mahatta Humaid Formation, Gharif and Al Khalata formations; Shu’aiba Formation, and Natih Formation.
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References• Al-Barwani, B., & McClay, K. (2008). Salt tectonics in the Thumrait area, in the southern part of
the South Oman Salt Basin: implications for mini-basin evolution. GeoArabia, 13(4), 77-108.• Clarke, M. W. H. (1988). Stratigraphy and rock unit nomenclature in the oil-producing area of
interior oman. Journal of Petroleum Geology, 11(1), 5-60.• Forbes, G. A., Jansen, H. S., & Schreurs, J. (2010). Lexicon of Oman: Subsurface Stratigraphy:
Reference Guide to the Stratigraphy of Oman's Hydrocarbon Basins. Gulf PetroLink.• Nairn, A. E. M., & Alsharhan, A. S. (1997). Sedimentary basins and petroleum geology of the
Middle East. Elsevier.• Sharland, P. R., Archer, R., Casey, D. M., Davies, R. B., Hall, S. H., Heward, A. P., ... & Simmons,
M. D. (2001). Arabian Plate sequence stratigraphy. GeoArabia, Journal of the Middle East Petroleum Geosciences, 18(4).