About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

(Begin page 839)

AAPG Bulletin, V. 85, No. 5 (May 2001), P. 0839-0860.

Copyright ©2001. The American Association of Petroleum Geologists. All rights reserved.

Sequence stratigraphy and sea level history of the upper Paleocene strata in the Kopet-Dagh basin, northeastern Iran

A. Mahboubi,1 R. Moussavi-Harami,2 Y. Lasemi,3 R. L. Brenner4

1Department of Geology, Faculty of Sciences, Mashhad University, Mashhad 91384, Iran; email: [email protected]
2Department of Geology, Faculty of Sciences, Mashhad University, Mashhad 91384, Iran; email: [email protected]
3Department of Geology, Faculty of Sciences, Tarbiat-Moallem University, Tehran, Iran
4Department of Geoscience, University of Iowa, Iowa City, Iowa, 52242-1379; email: [email protected]

AUTHORS

Asadollah Mahboubi is a member of the geology faculty at Mashhad University, Iran. He received his B.S. degree in geology from Mashhad University, Iran, in 1984 and his M.S. degree in geology from Tarbiat-Moallem University in Tehran, Iran, in 1991. He is currently completing his Ph.D. at Tarbiat-Moallem University. Mahboubi was previously a lab instructor at Mashhad University and a researcher at Research Center of National Iranian Oil Company (NIOC) in Tehran.

Reza Moussavi-Harami is a professor and chairman of the Geology Department at Mashhad University, Iran, and adjunct professor at the University of Iowa. He received his B.S. degree in geology from Mashhad University in Iran in 1972, his M.S. degree in geology from the University of Oklahoma in 1977, and his Ph.D. from the University of Iowa in 1980. Since 1999 he has been serving as the president of the Geological Society of Iran.

Y. Lasemi received his B.S. degree from the Teacher Training College in Tehran, Iran, in 1972 and his M.S. degree and Ph.D. in geology from the University of Illinois in 1975 and 1980. He served as a consultant to the petroleum industry in the Illinois basin between 1981 and 1986. From 1987 to the present, he has been assistant and associate professor at the Tarbiat-Moallem University, Tehran, Iran. His main research interests include carbonate petrology and sequence stratigraphy.

Robert L. Brenner has been on the faculty of the Department of Geoscience at the University of Iowa since 1977. Prior to that, he worked for Conoco and Marathon Oil Company. He received his B.S. degree in geology from the City College of New York in 1963, an M.S. degree in geology from the University of Montana (Missoula) in 1964, and a Ph.D. in geology from the University of Missouri-Columbia in 1973.

ACKNOWLEDGMENTS

This project was aided by an AAPG 1998 Grants-in-Aid that was awarded to Asadollah Mahboubi to support his analytical work. We thank the Geology Department at Mashhad University for their support of fieldwork and thin-section preparation. Thanks also go to the Geological Survey of Iran northeastern branch for the their logistical support during the course of this study. The Department of Geology at Tarbiat-Moallem University of Iran also supplied financial support, and we acknowledge their support. The Department of Geoscience at the University of Iowa provided computer support. The constructive comments and suggestions provided by the AAPG reviewers J. Fred Read and Bob Luocks greatly enhanced this article, and we thank them for their time and efforts.

ABSTRACT

The intracontinental Kopet-Dagh basin formed after the Middle Triassic orogeny in northeastern Iran and southwestern Turkmenistan. This underexplored basin could provide significant petroleum reserves in the 21st century. The upper Paleocene Chehel-Kaman Formation is exposed along northwest-southeast-trending folds and is composed of carbonate strata and minor amounts of siliciclastic and evaporite beds. Six stratigraphic sections in the central and eastern parts of the basin have been used to divide the upper Paleocene (Thanetian) carbonate supersequence into four major carbonate lithofacies, each having multiple subfacies. These lithofacies represent open-marine, shoal, semirestricted lagoon, upper intertidal, and tidal-flat subenvironments that formed on a shallow carbonate ramp. In addition, there are two siliciclastic lithofacies consisting of calcareous shale (marl) and calcite-cemented sandstone.

The upper Paleocene interval consists of three depositional sequences (DS1, DS2, and DS3), bounded by type 2 (within the top of the underlying Pestehleigh Formation), type 2, and type 1 sequence boundaries, respectively. Sea level changes during the Thanetian in the Kopet-Dagh basin are similar to global changes proposed by Haq et al. (1988), with differences related to local and regional geological events. Upper Paleocene strata were deposited in about 4 m.y., within the range of second-order cycles. Each depositional sequence was developed as a third-order cycle composed of several shallowing-upward parasequences (fourth- to fifth-order cycles). We estimate that sea level fluctuations in the study area were between 5 and 11 m during development of parasequences.

(Begin page 840)

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].