Arefe Shabani Eraghi, Seyed Mohammad Zamanzade, Fariba Karami,
Volume 25, Issue 79 (12-2025)
Abstract
Reconstructing paleoclimate, particularly environmental temperature, plays a crucial role in understanding both current and future climate patterns. The aim of this research is to investigate the climatic conditions and estimate the ambient temperature during the Holocene period based on two sediment cores extracted from the Jazmurian Basin. Paleotemperature reconstruction was conducted using several methods, including the calculation of the standardized coefficient of variation of oxygen-18 and carbon-13 isotopes. For this purpose, the isotopic analysis of oxygen-18/oxygen-16 and carbon-13 was performed. In Jazmurian core 1, the initial temperature was estimated at 46°C. A decreasing trend of approximately 10°C was observed down to a depth of 175 cm, distributed across eight stratigraphic levels. At 175 cm, the temperature shows an increasing trend, followed by a decline at the subsequent level, and then a return to an increasing and stable trend in the next two levels. In Jazmurian core 2, the initial temperature was approximately 50°C. A sharp decrease in temperature is observed between depths of 80 to 125 cm. Subsequently, there is a slight increase of about 1°C, which remains relatively stable until a depth of 170 cm. Beyond this point, the temperature decreases again in the final two layers. The concentration of carbon-13 in core 1 ranges from 0 to 25.6, while in core 2 it varies between 25.9 and 27.1. In core 1, six carbon -13 isotope samples show a value of zero, indicating an absence of carbon-13 in those sediment layers. In contrast, core 2 displays a narrower range of variation in carbon-13 values. The isotopic and temperature variations observed in these sediment cores reflect different climatic phases during the Holocene in the Jazmurian region. Such climatic changes are often linked to cultural shifts, and the decline of ancient civilizations has frequently coincided with environmental transformations. The findings of this research may be of significant value to archaeology researchers, particularly those studying ancient Iranian civilizations.
