Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Stratigraphic Study of Upper Cretaceous rocks in east and southeast of Tehran

Document Type : Original Research Paper

Author
Alireza Karimi Bavandpur
Geological Survey of Iran, Tehran, Iran
Abstract
For the purpose of stratigraphic study of Upper Cretaceous rocks in east and Southeast of Tehran, five stratigraphic sections were measured and 350 thin sections studied. These sections are located in southwest of Valliabad village, north of Darbandak farm, north of Ghara-Cheshmeh village, Sepayeh and Za(h) mountains.
Stratigraphic and Palaeontologic observations indicates upper Coniacian (?), Santonian and Campanian age for the deposits of the area studied. The sequence is divided (by author) into three lithostratigraphic units, namely: KU 1, KU 2, KU 3.
The oldest unit (KU 1) consists of red conglomerates, sandstones, and calcareous sandstones. Pebbles of conglomerates include abundant microfauna, of which the most important are: Globotruncana lapparenti lapparenti, Glt. marginata, Glt. lapparenti tricarianata, Stomiosphaera sphaerica, Heterohelix sp.
With regards to the above-mentioned microfauna, and the position of the red unit under KU 2, as well as having an age of middle to upper Santonian, it seems that an upper Coniacian (?)- lower Santonian age may be considered for KU 1 unit.
The next younger unit (KU 2) consists of Bryozoa and rudist limestone, glauconitic, sandy limestone with abundant Exogyra, Cherty limestone, marly limestone with abundant Echinoids overlying conformably the lower KU 1 red unit. In sandy limestone horizon, abundant Exogyra virgula are found indicating age of Santonian. In addition, in the upper marly limestone horizon, abundant Echinoids such as Micraster coranguinum are found indicating the uppermost Santonian age. Thus, KU 2 unit can be related to middle- upper Santonian.
The youngest unit of Upper Cretaceous deposits consists of Globotruncana - bearing sandy- marly limestone (KU 3) with a good development in Darbandak and Sepayeh mountain. Abundant microfauna of this unit shows Campanian age:
Globotruncana cf. elevata, Glt. cf. conica, Glt. arca, Bolivinoides aff. postulata, Calcisphaerulidae.
In spite of previous observations (Dellenbach, 1964), but nevertheless this study shows that: (1) there is no K2a unit with Turonian age; (2) Santonian deposits (Exogyra sandy limestone "KU 2") with remarkable thickness are found in Sepayeh mountain, and (3) there is no unconformity in Sepayeh mountain.
Subjects
 
Alavi, M. & Flandrin, J., 1970, La limite Paleogeographique des domains de l'Elbourz et de l,Iran central dans la region de Djam (Kepartment de Semnan, Iran). C.R. Acad. Sci, Paris, Ser. D, V. 270, pp. 1424-1426
Allenbach, p., 1966, Geologie und Petrographie des Damavand und seiner Umgehung (Zentral Elburz), Iran. Eiden. Tech. Hochsch., Univ. Zurich, Mitt. Geol. Inst., N. F. 63, 144 pp.
Assereto, R. & Ippolito, I., 1964, Osservazioni Preliminar sul cretaceo della bassa valle del Lar (Elburz centrale, Iran). Riv. Ital. Paleont. Strat. V. 70, no.4, pp. 1133- 1182
Assereto, R., 1966, Geological map of upper Djadjerud und Lar valleys (central Elburz, Iran). Inst. Geol, Univ. Milano, Serie G, Publ. no. 232, 86 pp.
Bozorgnia, F., 1964, Microfacies and micro organisms of Paleozoic through Tertiary Sediments of some Parts of Iran. Nat, Iran. Oil. Co.
Cushman, J. A., 1958, Foraminifera, their classification and Economic use. Fourth Ed., Harvard Univ.
Dellenbach, J., 1964, Contribution a l'etude geologique de la region situee a l'est de Teheran (Iran). These de doct.; Fac. Sic., Univ. Strasbourg (France), 117 pp.
Engalenc, M., 1968, Contribution a la Geologie, Geomorphologie, Hydrogeology de la region de Tehran (Iran). C. E. R. H., Montpellier, France, 365 pp.
Gansser, A. & Huber, H., 1962, Geological observations in the central Elburz, Iran. Schw. Min. petr. Mitt., V. 42(2), pp. 583-630 G. S. I. (Geological survey of Iran), 1972, Central Alborz map series, 1:100,000, Damavand sheet. Geological Survey of Iran, Tehran.
Khosrow Tehrani, Kh., 1977, Etude Stratigraphique du cretace Sup et du paleocene de 1'Iran central, region comprise entre Esfahan, Djandaghet Yazd, these de doct. d'Elat, Paris.
Krumbeck, L., 1922, Stratigraphisch Ergebnisse Von Neider mayer's Reise durch Persien: Zentralbl. Min, etc. Abt B., 1922, no. 1. pp. 19-23.
Mehrnush, M. & Partoazar, H., 1977, Selected Microfauna of Iran. Geol. Surv. of Iran, Rep. no. 33.
Moor, R. C. & others, 1964, Treatise on Invertebrate Paleontology (Parts C, N, S, T, U, V). Geol. Soci. of America & Univ. of Kansas.
Murray, J. W., 1985, Atlas of Invertebrate macrofossils. Longman.
Nazemi, F. & Grubic, A., 1959, Note preliminaire Sur le Cretace a Rudistes de l'Anti- Alborz (Elbourz) Occidental (E et SE de Tehran, Iran): Bull. Soc. Geol. France, Ser. 7, V.1, no. 9, p. 944-953.
Riviere, A., 1934, Contribution a l'etude geologique de l'Anti- Elbourz. Rev. Geogr. phys. Geol. Dyn. 7, pp. 277-298
Seyed- Emami, K. & Brants, A. & Bozorgnia F., 1971, Contributions to the Paleontology and stratigraphy of Iran, Part 2. Geol. Surv. of Iran, Rep. no. 20, pp. 5-40
Steiger, R., 1966, Die Geologie der West- Firuzkuh- Area (Zentral Elburz/ Iran). Eidgen, Tech. Hochsch., Univ. Zurich, Mitt. Geol. Isnt., N. F. 68, 145pp.
Stocklin, J. & Setudehnia, A., 1971, Stratigraphic Lexicon of Iran. Geol. Surv. of Iran, Rep. no. 18.
Sussli, P. E., 1976, The Geology of the Lower Haraz Valley Area, Central Alborz, Iran. Geol. Surv. of Iran, Rep. no. 38
Scientific Quarterly Journal of Geosciences
Volume 3, Issue 11
Spring 1994, Vol. 3, No. 11
Spring 1994
Pages 34-49