Sedimentology and sedimentary geochemistry as proxies for Holocene climate change in the Hotu Cave deposits (South of Gorgan Gulf)

Sorayaye Zafar, Sepideh; Lak, Razyeh; Fazeli Nashli, Hassan; Aleali, Mohsen

doi:10.22071/gsj.2026.587661.2256

Sedimentology and sedimentary geochemistry as proxies for Holocene climate change in the Hotu Cave deposits (South of Gorgan Gulf)

Articles in Press

Document Type : Original Research Paper

Authors

Sepideh Sorayaye Zafar ¹

Razyeh Lak ²

Hassan Fazeli Nashli ³

Mohsen Aleali ¹

¹ Department of Geology, Sciences and Research Branch, Islamic Azad University, Tehran, Iran

² Professor, Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran

³ Department of Archaeology, Faculty of Literature and Humanity, University of Tehran, Tehran, Iran.

10.22071/gsj.2026.587661.2256

Abstract

This study investigates the sedimentary sequences of the Hotu Cave deposits, located in the west of Behshahr, to reconstruct the paleoenvironmental and paleoclimatic conditions of the Late Holocene in the southeast of the Caspian Sea. Based on sedimentological analyses and facies variations, three distinct sedimentary facies representing alluvial fan, fluvial, and marginal lacustrine environments were identified. A total of 25 sedimentary samples were collected and subjected to elemental analysis using ICP-OES and XRF techniques. Additionally, seven samples containing plant remains and bone fragments were dated using 14C-AMS isotopic methods. To reconstruct the paleoclimatic and environmental condition, elemental ratios including Co/Cr, Mn/Al, K/Al, Rb/Al, Si/Fe, and Ti/K were employed to assess the input of fine-grained clastic materials (suspended and clayey sediments), the intensity of weathering and erosion within the catchment area, and the fluctuations of the Caspian Sea level. The paleoclimatic variations identified in this region during the Holocene show strong correlation with climatic events documented in East Asia. This study identifies at least two distinct arid periods around 4.2 and 8.2 ka BP. These arid episodes appeared abruptly in the region and terminated gradually, whereas humid periods exhibited a gradual onset followed by abrupt terminations.

Keywords

Paleoclimate

Sedimentology

Sedimentary geochemistry

Hotu Cave

Gorgan Gulf

Holocene

Subjects