UNDERSTANDING CULTURAL ADAPTATIONS TO CLIMATE AND ENVIRONMENTAL CHANGES IN WADI HASA, JORDAN; THE NEED FOR THE SPECIALIST

One of the primary goals of archaeology is to understand the human ecology of past cultures. What were the subsistence strategies used by people and how did they adapt to climate and environmental change? Wadi Hasa, a perennial stream located in east-central Jordan, contains thick accumulations of late Pleistocene and Holocene fill deposits and an abundance of Middle Paleolithic through Pre-Pottery Neolithic archaeology. Archaeologists and geologists have been working in this valley for more than 30 years to understand human occupation, past environments, and how humans functioned within their surroundings. Initial environmental reconstructions identified a series of late Pleistocene paleolakes that came and went, yet it was unclear how, when, and why these lakes formed, how big they were, and what caused their disappearance. We initiated work in Wadi Hasa in 2005 to understand past changes in the hydrology of Wadi Hasa and how these changes related to climate change. We interpreted depositional environments within Wadi Hasa based on the sedimentology and microfaunal assemblages (mostly ostracodes), and identified the age of these depositional environments with radiocarbon dating, amino acid racemization, luminescence, and stratigraphic relations. We did not find evidence of paleolakes within Wadi Hasa, but wetlands and in-stream wetlands were present episodically. Moreover, Wadi Hasa has experienced a series of aggradation and incision cycles that had never been documented previously. Our interpretations of the paleoenvironment and environmental change are markedly different from previous researchers and have broad implications for understanding how humans interacted with this landscape. Moreover, detailed mapping and dating of the deposits identified gaps in the geologic record that explains the lack of archaeological deposits during these intervals. Ultimately, we stress the importance of collaborating with geologists that have experience in the types of deposits being examined (i.e. specialists), and not just assuming any geologist can play the role of geoarchaeologist. Just as archaeologists cannot interpret material culture in any environment, geologists cannot interpret the sediments or rocks in any environment.