Petrography and Geochemistry of Paleo-alluvial Deposits in South of Lorestan: Implications for Provenance Analysis

Nasiri, Yaghub; Taghdisi Nikbakht, Samira; Sedaghatnia, Mostafa

doi:10.22071/gsj.2026.576501.2246

Petrography and Geochemistry of Paleo-alluvial Deposits in South of Lorestan: Implications for Provenance Analysis

Articles in Press

Document Type : Original Research Paper

Authors

Yaghub Nasiri ¹

Samira Taghdisi Nikbakht ²

Mostafa Sedaghatnia ³

¹ Department of Geology, Faculty of Sciences, University of Gonabad, Gonabad, Iran

² Assist. Prof., Department of Geology, Faculty of Sciences, University of Gonabad, Gonabad, Iran

³ PhD Graduate, Central Laboratory Expert of Lorestan University, Khorramabad, Iran

10.22071/gsj.2026.576501.2246

Abstract

In this study, the alluvial terraces of southern Lorestan (Mamulan–Poldokhtar region) were investigated using petrographic and geochemical approaches to determine their provenance. Four alluvial terrace outcrops along the Mamulan–Poldokhtar road were selected for sampling. Fifteen gravel-sized clast samples were collected for petrographic investigation, 20 sandstone samples were selected for modal analysis, and 12 mudrock samples were analyzed geochemically using XRF and ICP–MS. Modal analysis of the sandstone samples plotted on the QmFLt diagram indicates a recycled orogen provenance. The petrofacies of the studied deposits, based on the QFL diagram, are dominated by chert arenite and calclithite arenite. The abundance of sedimentary lithic fragments, particularly chert and carbonate clasts, indicates extensive recycling of older sedimentary successions and demonstrates that sedimentary recycling was the dominant process controlling the provenance of the detrital material. Geochemical results indicate that the source rocks experienced moderate chemical weathering under arid climatic conditions.

Keywords

Alluvial terraces

Geochemistry

Provenance

Lorestan

Zagros

Subjects