Abrupt climate variability since the last deglaciation based on a high-resolution, multi-proxy peat record from NW Iran: The hand that rocked the Cradle of Civilization? (original) (raw)

New multi-proxy record shows potential impacts of precipitation on the rise and ebb of Bronze Age and imperial Persian societies in southeastern Iran

Quaternary Science Reviews, 2022

The Achaemenids and Sasanian 'Persian' Empires were significant political, economic, and social forces in the Late Bronze Age and Late Antiquity Eurasia, respectively, which have left marks on the heritage of the Mediterranean and Middle Eastern world. While attention is often focused on military and political conditions when discussing the prosperity and decline of these imperial powers, their realms, which crossed a variety of environmental settings, were highly dependent on the predictability of rainfall that drove agriculture and effective provisioning. Here, we present a multi-proxy sedimentological, geochemical, and palynological record from a 2.5-m long peat deposit near the excavation site in Konar Sandal near Jiroft in southeastern Iran, covering 4000-850 cal yr BP. Around 3950 cal yr BP a wet period prevailed based on elemental ratios, stable C isotope, pollen, and diagnostic lipids. Between 3900 and 3300 cal yr BP, wet/semi-wet conditions developed with the appearance of Cerealia-type pollen. Dry and windy conditions followed (ca. 3300-2900 cal yr BP), which coincided with the Siberian anticyclones and climatic shifts developing in the Eastern Mediterranean region. Consequently, the Bronze Age settlements around Jiroft, dependent on agriculture, underwent a steady decline. A prolonged wet period followed (ca. 2900-2300 cal yr BP) with the abundance of Sparganium-type pollen and the aquatic lipid proxy (Paq). This change coincided with intensive agricultural practices and the flourishing of the powerful Median and Achaemenid empires. The shift to high Ti/Al ratios coeval with the lowest δ13COM values suggests an increase in aeolian activity and dry conditions ca. 2100-1650 cal yr BP. The Jiroft valley again experienced wet conditions between 1550 and 1300 cal yr BP, which overlapped with the economic prosperity of the middle to late Sasanian empire. The paleoenvironmental reconstruction indicates that wet periods and intensive agriculture coincide with the Persian empires' zenith, political influence, and economic affluence. Therefore, contextualized and detailed paleoenvironmental records are desirable to explore the interplay of political and climatic factors in the development and fragmentation of the ancient settlements and imperial powers in Eurasian history.

The Impact of Climate on Human Occupations in Iran from the Neolithic to the Early Iron Age. An Attempt to Link Archaeological and Paleoclimate Records

COMING TO TERMS WITH THE FUTURE: Concepts of Resilience for the Study of Early Iranian Societies, 2023

The present article aims to assess the possible effects of climate change on settlement density changes that are indicative of the decline and rise of societies. Archaeological data and regional diachronic changes in settlement densities are compiled for eight geographic regions and contrasted with evidence for major rapid climate change (RCC) events (11.1, 10.3, 9.4/9.2, 8.2, 5.9, 5.2, 4.2, and 3.2/2.9) as reflected in high-resolution sedimentary archives. There are significant differences in settlement density in the east and west of the Iranian Plateau, often with different responses to the same RCC event, an indication that factors other than climate contributed to the settlement density in these regions. From another standpoint, it seems that the human occupations of the inner part of the Iranian Plateau had weaker responses to RCC events than those in the outer parts adjacent to the neighboring regions of Mesopotamia and the Indus Valley.

Mid Holocene environmental and climatic change in Iran

The 4th Millennium sits at the end of a global climate re-organisation following the Holocene climatic optimum. The speed and timing of the shift from early to late Holocene climatic settings appears to have varied across the region. At higher temporal resolutions there are currently few local records form Iran that can look at centennial-scale climatic change within the 4th Millennium and this is an important area for future research, especially to confirm the local impact of the 5.2 kyr event. The complex interplay between people, climate, landscape stability and tectonics through much of the Holocene in Iran, and it’s location at the crossroads between different cultural and climatic influences make this information difficult to obtain. There is a need to think carefully about how to unpick the different forcings from natural and archaeological archives and a clear need for multidisciplinary programmes to take this work forward.

Early Pleistocene climate in western arid central Asia inferred from loess-palaeosol sequences

Scientific reports, 2016

Arid central Asia (ACA) is one of the most arid regions in the mid-latitudes and one of the main potential dust sources for the northern hemisphere. The lack of in situ early Pleistocene loess/dust records from ACA hinders our comprehensive understanding of the spatio-temporal record of aeolian loess accumulation and long term climatic changes in Asia as a whole. Here, we report the results of sedimentological, chronological and climatic studies of early Pleistocene loess-palaeosol sequences (LPS) from the northeastern Iranian Golestan Province (NIGP) in the western part of ACA. Our results reveal that: 1) Accumulation of loess on the NIGP commenced at ~2.4-1.8 Ma, making it the oldest loess known so far in western ACA; 2) the climate during the early Pleistocene in the NIGP was semi-arid, but wetter, warmer, and less windy than during the late Pleistocene and present interglacial; 3) orbital-scale palaeoclimatic changes in ACA during the early Pleistoceneare in-phase with those of ...

Holocene settlement shifts and palaeoenvironments on the Central Iranian Plateau: investigating linked systems.

Schmidt, A., M. Quigley, M. Fattahi, G. Azizi, M. Maghsoudi & H. Fazeli 2011. Holocene settlement shifts and palaeoenvironments on the Central Iranian Plateau: investigating linked systems. The Holocene 21(4): 583-595., 2011

For thousands of years, humans have inhabited locations that are highly vulnerable to the impacts of climate change, earthquakes, and floods. In order to investigate the extent to which Holocene environmental changes may have impacted on cultural evolution, we present new geologic, geomorphic, and chronologic data from the Qazvin Plain in northwest Iran that provides a backdrop of natural environmental changes for the simultaneous cultural dynamics observed on the Central Iranian Plateau. Well-resolved archaeological data from the neighbouring settlements of Zagheh (7170-6300 yr BP), Ghabristan (6215-4950 yr BP) and Sagzabad (4050-2350 yr BP) indicate that Holocene occupation of the Hajiarab alluvial fan was interrupted by a 900 year settlement hiatus. Multi-proxy climate data from nearby lakes in northwest Iran suggest a transition from arid early Holocene conditions to more humid middle Holocene conditions from ca. 7550-6750 yr BP, coinciding with the settlement of Zagheh, and a peak in aridity at ca. 4550 yr BP during the settlement hiatus. Palaeoseismic investigations indicate that large active fault systems in close proximity to the tell sites incurred a series of large (MW ~7.1) earthquakes with return periods of ~500-1000 years during human occupation of the tells. Mapping and optically stimulated luminescence (OSL) chronology of the alluvial sequences reveals changes in depositional style from coarse grained unconfined sheet flow deposits to proximal channel flow and distally prograding alluvial deposits sometime after ca. 8830 yr BP, possibly reflecting an increase in moisture following the early Holocene arid phase. The coincidence of major climate changes, earthquake activity, and varying sedimentation styles with changing patterns of human occupation on the Hajiarab fan indicate links between environmental and anthropogenic systems. However, temporal coincidence does not necessitate a fundamental causative dependency.

Human-Climate Connection in North Central Iran Between 6000 and 2700 BCE

Iranian Journal of Archaeological Studies, 2020

During the Holocene, man's challenges with climate entered a new phase. Holocene climatic cycles, by creating dry events, have imposed many subsistence tensions on water-dependent communities. The semi-arid and arid region of North Central Iran, which has been very vulnerable to any climate change, experienced unfavorable environmental conditions during these climatic events. So far, only a handful of Early Holocene rural settlements have been found in the region, possibly because of the mostly arid climate of the period. In general, the first evidence of Neolithic villages in North Central Iran dates back to the beginning of the Middle Holocene, after the 8.2 ka BP event. The first cultural flourishing of this region can be seen from the last quarter of the sixth millennium BCE. Each cultural flourishing period seems to have declined for some time with the occurrence of a dry event. The effects of climatic tensions on human societies in North Central Iran have been found around 6500-6000, 5700-5400, 5000-4700, 4300-4000, and 3300-2700 BCE. According to data analysis, the frequency of settlements and the trend of cultural progress gradually peaked from the early sixth millennium to the mid-fourth millennium BC, but in the second half of the latter millennium, a gradual decline began which led to the Bronze Age collapse in ca. 2700 BCE. This event probably occurred due to the drop in temperature and the increase in the frequency and severity of aridity in the transition phase to the Late Holocene.