Hostname: page-component-848d4c4894-ndmmz Total loading time: 0 Render date: 2024-05-15T12:09:27.263Z Has data issue: false hasContentIssue false

Stratigraphy of the Mesozoic rocks above the Semail Ophiolite, Oman

Published online by Cambridge University Press:  01 May 2009

N. H. Woodcock
Affiliation:
Department of Earth Sciences, Downing Street, Cambridge CB2 3EQ
A. H. F. Robertson
Affiliation:
Grant Institute of Geology, West Mains Road, Edinburgh EH9 3JW

Summary

A revised stratigraphy is presented for the rocks which lie between the Upper Cretaceous Semail ophiolite and its post-emplacement sediment cover of uppermost Cretaceous to Tertiary age. Above the pelagic sediments of the ophiolite (Suhaylah Formation, Cenomanian–Turonian) occur ophiolite-derived clastic sediments (Zabyat Formation, ?Turonian–?Campanian) related to early stages of ophiolite emplacement. These formations are structurally overlain by the Batinah Complex, comprising Triassic to Cretaceous lithologies, all previously equated with the Hawasina rocks that now lie tectonically beneath the ophiolite. We recognize a lower melange unit to the complex, which demonstrably includes Hawasina lithologies. The melange formed by superficial rather than deep processes, but the mechanism by which Hawasina material was supplied to the ophiolite surface is unproven. The upper unit of the Batinah Complex shows a coherent stratigraphy which contrasts with that of the Hawasina. It comprises three main allochthonous tectonic sheets, within which we recognize three formations and one other informal unit. The upper Batinah Complex may have been tectonically derived not from the now subjacent Arabian margin but from another margin with a passive Mesozoic history.

Type
Articles
Copyright
Copyright © Cambridge University Press 1982

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Brookfield, M. E. 1977. The emplacement of giant ophiolite nappes, I. Mesozoic–Cenozoic examples. Tectonophysics 37, 247304.CrossRefGoogle Scholar
Carney, J. N. & Welland, M. J. P. 1974. Geology and mineral resources of the Oman Mountains. GB Inst. Geol. Sci. Overseas Div. Rept. 27, 504 pp.Google Scholar
Dewey, J. F. 1976. Ophiolite obduction. Tectonophysics 31, 93120.CrossRefGoogle Scholar
Fleet, A. J. & Robertson, A. H. F. 1980. Ocean-ridge metalliferous and pelagic sediments of the Semail Nappe, Oman. J. geol. Soc. Lond. 137, 403–22.CrossRefGoogle Scholar
Gealey, W. K. 1977. Ophiolite obduction and geologic evolution of the Oman mountains and adjacent areas. Bull. geol. Soc. Am. 88, 1183–91.2.0.CO;2>CrossRefGoogle Scholar
Glennie, K. W., Boeuf, M. G. A., Hughes Clarke, M. W., Moody-Stuart, M., Pilaar, W. F. H. & Reinhardt, B. M. 1973. Late Cretaceous nappes in Oman Mountains and their geologic evolution. Bull. Am. Ass. Petrol. Geol. 57, 527.Google Scholar
Glennie, K. W., Boeuf, M. G. A., Hughes Clarke, M. W., Moody-Stuart, M., Pilaar, W. F. H. & Reinhardt, B. M. 1974. Geology of the Oman Mountains. Verh. K. Ned. geol. mijnbouwkd. Genoot. 31, 1423.Google Scholar
Graham, G. M. 1980. Evolution of a passive margin, and nappe emplacement in the Oman Mountains. Proc. Int Ophiolite Sym. Cyprus 1979, 414–23.Google Scholar
Lanphere, M. A. 1979. K–Ar ages of metamorphic rocks at the base of the Samail ophiolite, Oman. Eos 60, 963.Google Scholar
Lees, G. M. 1928. The geology and tectonics of Oman and parts of south-eastern Arabia. Q. Jl geol. Soc. Lond. 84, 585670.CrossRefGoogle Scholar
McCulloch, M. T. & Wasserburg, G. J. 1979. A Nd isotopic study of the Samail ophiolite. Eos 60, 963.Google Scholar
Open University, 1980. 1:100,000 geological map, Wadi Jizi, Oman. U.K. Directorate of Overseas Survey.Google Scholar
Reinhardt, B. M. 1969. On the genesis and emplacement of ophiolites in the Oman Mountains geosyncline. Schweiz. mineral petrogr. Mitt. 49, 130.Google Scholar
Searle, M. P., Lippard, S. J., Smewing, J. D. & Rex, D. C. 1980. Volcanic rocks beneath the Semail ophiolite nappe in the northern Oman Mountains and their tectonic significance in the Mesozoic evolution of Tethys. J. geol. Soc. Lond. 137, 589604.CrossRefGoogle Scholar
Searle, M. P. & Malpas, J. 1981. Structure and metamorphism of rocks beneath the Semail ophiolite of Oman and their significance in ophiolite obduction. Trans. R. Soc. Edinb. 71, 247–62.CrossRefGoogle Scholar
Smewing, J. D., Simonian, K. O., Elboushi, I. M. & Gass, I. G. 1977. Mineralized fault zone parallel to the Oman ophiolite spreading axis. Geology. 5, 534–8.2.0.CO;2>CrossRefGoogle Scholar
Tilton, G. R., Wright, J. E. & Hopson, C. A. 1979. Uranium-lead isotopic ages of the Samail ophiolite, Sultanate of Oman. Eos 60, 962.Google Scholar
Tippit, P. R. & Pessagno, E. A. 1979. The age of the Semail ophiolite based on radiolarian biostratigraphy (Abstract). Eos 60, 692.Google Scholar
Tschopp, R. H. 1967. The general geology of Oman. Proc. 7th World Petroleum Congr. Mexico, 2, 231–41.Google Scholar
Welland, M. J. P. & Mitchell, A. H. G. 1977. Emplacement of the Oman ophiolite: a mechanism related to subduction and collision. Bull. geol. Soc. Am. 88, 1081–8.2.0.CO;2>CrossRefGoogle Scholar
Woodcock, N. H. 1979. The use of slump structures as palaeoslope orientation estimators. Sedimentology 26, 8399.CrossRefGoogle Scholar