Boletín de la Sociedad Geológica Mexicana Volumen 73, núm. 1, A140920, 2021 http://dx.doi.org/10.18268/BSGM2021v73n1a140920

Sedimentary environment and provenance of sandstones from the Qadir member in the Nayband Formation, Tabas block, east-central Iran

Ambiente sedimentario y procedencia de las areniscas del miembro Qadir de la Formación Nayband, bloque de Tabas, centro-este de Irán

Ehsan Zamaniyan¹, Mohammad Khanehbad^1,*, Reza Moussavi-Harami¹,Asadollah Mahboubi¹

¹ Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Azadi Square, Mashhad, Iran.

* Corresponding author: (M. Khanehbad) This email address is being protected from spambots. You need JavaScript enabled to view it.

How to cite this article:

Zamaniyan, E., Khanehbad, M., Moussavi-Harami, R., Mahboubi, A., 2021, Sedimentary environment and provenance of sandstones from the Qadir member in the Nayband Formation, Tabas block, east-central Iran: Boletín de la Sociedad Geológica Mexicana, 73 (1), A140920. http://dx.doi.org/10.18268/BSGM2021v73n1a140920

ABSTRACT

Qadir Member of Nayband Formation, located in East of Central Iran, has developed to a great extent. Investigation of the lithofacies and sedimentary environment, resulted in identification of the deltaic and marine deposits. Based on field evidence and facies features, Qadir Member consists of two lithofacies, including carbonate and siliciclastic facies. The siliciclastic facies were identified as having four sandstone facies including Sr, Sh, Sp, St, three fine-grained lithofacies, including FI, Fm, Fl (Sr) / Sr (FI) and one coal facies. Also, regarding the field, laboratory studies, and identification of lithofacies, the coastal plain, deltaic (including deltaic plain, proximal delta front, distal delta front, and prodelta) and open marine environments were identified for Qadir Member which is is under the impact of tidal currents. The chemical weathering index (71%) indicated semi-arid to semi-humid conditions and plotting the geochemical data showed the provenance of re-cycling and active continental margin and because of Chemical Index of Alteration, the weathering rate was found to be rather medium to high. The geochemical diagrams also showed a probable source of the intermediate igneous and sedimentary rocks. The active continental margin conditions for this deposit could suggest the Neotethys subduction under Iran’s plate and volcanic activity at the end of Triassic, which coincided with the early Cimmerian orogeny in Alborz and Central East Iranian Microcontinent.

Keywords: Nayband Formation, Triassic, Tabas Block, Sedimentary environment, Provenance.