Determining microfacies of phosphate bearing Pabdeh Formation in paleogene carbonate ramp of Lar anticline (Northeast of Gachsaran)

Shariati, Sh.

doi:10.22071/gsj.2017.54133

Document Type : Original Research Paper

Author

Sh. Shariati

Assistant Professor, Department of Geology, Sari Branch, Islamic Azad University, Sari, Iran

https://doi.org/10.22071/gsj.2017.54133

Abstract

Pabdeh Formation comprised carbonate-siliciclastic succession of Zagros fold-thrust belt in south west of Iran. The studied area is located in Lar Mountains (North East of Khami anticline) which extend in a northwest-southeast direction Parallel to the Zagros sedimentary basin trend. Microfacies analysis especially in phosphate-bearing horizons and semiquantitative investigations of foraminiferal contents as an aid to determining the depositional environment of marine deposits was the aim of this study. For this purpose, 300 sample were collected from 410-m stratigraphical section in the Pabdeh Formation. From these 126 thin section were compiled based on lithology and facies alternations. Petrographical studies and microfacies analysis of Pabdeh Formation demonstrate that eight lithofacies can be recognized in this interval. Planktonic Foraminiferal mudstone and indicating the presence of turbidite microfacies suggest deposition in a ramp setting. On the other words the depositional environment of the Pabdeh Formation evolved into an outer ramp setting. Microfacies of the upper part of Pabdeh Formation reveal deposition in a shallowing-upward depositional environment. With attention to the items mentioned above the Pabdeh Formation is dominated by a pelagic microfauna that deposited in a deep ramp setting (Outer ramp) which passed into a shallower ramp parts (Middle ramp).

Keywords

20.1001.1.10237429.1396.27.105.11.4

References

References

Alavi, M., 2004- Regional stratigraphy of the Zagros fold thrust belt of Iran and its proforeland evolution, American Journal of Science, Vol. 304, P. 1–20.

Bahrami, M. and Parvanehnezhad Shirazi, M., 2010- Microfacies and sedimentary environments of Gurpi and Pabdeh Formations and the type of Mesozoic– Cenozoic boundary in Fars province, Iran, Journal of Applied Geology. Vol. 5, No. 4: 330-335.

Baltzer, F. and Purser, B. H., 1990- Modern alluvial fan and deltaic sedimentation in a foreland Tectonic setting: the lower Mesopotamian plain and the Arabian Gulf: Sedimentary Geology, v. 67, p. 175–195.

Berger, W. H. and Diester Haass, L., 1988- Paleoproductivity; the benthic/planktonic ratio in foraminifera as a productivity index, Marine Geology, Vol. 81: p. 1-4.

Buchette, T. P. and Wright, V. P., 1992- Carbonate ramp depositional system.Sedimentary Geology, 79, 3-57. Carozzi, A.V., Gerber, M. S. 1978, Sedimentary Chert Breccia: A Mississippian Tempestite, Jour. Sedim. Petrol, 48, 705-708.

Daneshian, J., Shariati, Sh. and Salsani, A., 2015- Biostartigraphy and Planktonic Foraminiferal abundance in Phosphate-Bearing Pabdeh Formation of the Lar Mountains (SW Iran), Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen. Vol, 278/2. 175-189.

Dunham, R. J., 1962- Classification of Carbonate Rocks According to depositional texture, Ham, W. E. (Ed.), Classification of Carbonate Rocks. American Association of Petroleum Geologists, Memoir, Vol. 1, pp. 80-121.

Falcon, N. L., 1969- Problems of the relationship between surface structure and deep displacements illustrated by the Zagros Range, inKent, P. E., Satterthwaite, G. E. and Spencer, A. M., editors, Time and place in orogeny: London, Geological Society Special Publication 3, p. 9–22.

Flugel, E., 2004- Microfacies of carbonate rocks. Analysis, Interpretation and Application, Second Edition, Springer-Verlag Berlin Heidelberg. 984 pp.

Gibson, T. G., 1989- Planktonic Benthonic Foraminiferal Rations; Modern Patterns and Tertiary Applicability. Marine Micropaleontology, 15; 29-52.

Haq, B. U., Hardenbol, J. and Vail, P. R., 1988- Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change. In: C.K. Wilgus, B. S. Hastings, C. G. St. C. Kendall, H. Posamentier, J. Van Wagoner and C.A. Ross (Eds.), Sealevel changes: an integrated approach.SEPM Special Publication42, 71–108.

Kassler, P., 1973- The structural and geomorphic evolution of the Persian Gulf, in Purser, B. H., editor, The Persian Gulf: Holocene carbonate sedimentation and diagenesis in a shallow epicontinental sea: Berlin and New York, Springer-Verlag, p. 11–32.

Khosravi Khorasani, P., Hadavi1, F., Ghasemi-Nejad, E. and Mousavi-Harami, R., 2014-Biostratigraphy and Paleoecological Study of Pabdeh Formation in Interior Fars, Zagros Basin, Iran. Open Journal of Geology, 4, 571-581.

Lees, G. M. and Falcon, N. L., 1952- The geographical history of the Mesopotamian plains: Geographical Journal, v. 118, p. 24–39.

Mohseni, H. and Al-Aasm, I. S., 2004- Tempestite deposits on a storm- influenced carbonate ramp: an example from the Pabdeh Formation (Paleogene), Zagros Basin, SW Iran: Journal of Petroleum Geology, v. 27, p. 163-178.

Pedley, M., 1998- A review of sediment distributions and processes in Oligo-Miocene ramps of the southern Italy and Malta (Mediterranean divide), In: Wright, V. P. and Burchette, T.P., (Eds.) Carbonate Ramps. Geol. Soc. London, Spec. Publ. 149, 163-180.

Purser, B. H., 1973- Sedimentation around bathymetric highs in the southern Persian Gulf, in Purser, B. H., editor, The Persian Gulf: Holocene carbonate sedimentation and diagenesis in a shallow epicontinental sea: Berlin and New York, Springer-Verlag, p. 157–177.

Van der Zwaan, G. J., Jorissen, F. J. and De Stigter, H. C., 1990- The depth-dependency of planktonic/benthic foraminiferal ratios; constraints and applications, Marine Geology, 95; 1-16.

Wade, B. S., Pearson, P. N., Berggren, W. A. and Heiko, P., 2011- Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibrationto the geomagnetic polarity and astronomical time scale. - Earth-Science Reviews, 104; 111-142.

Ziegler, M. A., 2001- Late Permian to Holocene Paleofacies Evolution of the Arabian Plate and its Hydrocarbon Occurrences. GeoArabia, 6, 3, 445-504

Scientific Quarterly Journal of Geosciences

Determining microfacies of phosphate bearing Pabdeh Formation in paleogene carbonate ramp of Lar anticline (Northeast of Gachsaran)

References

References

Volume 27, Issue 105
December 2017
Pages 97-104

Determining microfacies of phosphate bearing Pabdeh Formation in paleogene carbonate ramp of Lar anticline (Northeast of Gachsaran)

References

References

Volume 27, Issue 105December 2017Pages 97-104

Volume 27, Issue 105
December 2017
Pages 97-104