Mid- to late-Holocene archaeology, environment and climate in the northeast Kurdistan region of Iraq

This work presents new data from phytolith and speleothem analyses that cover the middle to late Holocene from northeastern Iraq in the Kurdistan region. Coupling these data with previous work, we demonstrate how the region's environment and climate developed during a time when agriculture became not only established but settlements started to transform into larger urban areas. Results demonstrate a wetter phase during the middle Holocene relative to the present period; a highly seasonal climate with one rainy season is also suggested between 8025 +/- 38 and 6977 +/- 219 BP. Phytoliths not only suggest a relatively wet environment but they also indicate a diversity of plants used for settlement activity. Sedimentary results complement the indication of a relatively wetter middle Holocene. Archaeologically, terraced construction found in Gurga Chiya and the presence of drought tolerant crops suggest adaptation to stronger, seasonal rains and seasonal droughts in the middle Holocene. Sedimentary, phytolith, and speleothem results suggest relatively drier late-Holocene conditions, although the region continued to be conducive for rainfed agriculture.