An investigation of local scale human/landscape dynamics in the endorheic alluvial fan of the Murghab River, Turkmenistan

摘要

Endorheic or inland deltas, commonly found across the deserts of Central Asia, represent unique anduddynamic ecotones that are still not fully understood. These regions of environmental and landscapeudtransition as well as social liminality straddle the line between fertile, sustainable environments and lessudproductive desertic regions less capable of sustaining significant human occupation. Because suchudboundary areas are dynamic and often unpredictable, they are excellent case studies through which toudstudy the complex processes that have characterized human/environmental relationships throughoutudthe late Holocene.udThis paper focuses on the local variability that characterizes these relationships in one such region, theudterminal fan of the Murghab River in Turkmenistan. Populated since at least the late 5th millennium BPudand likely earlier, the region has been variously described as an oasis environment in which deserticudprocesses have been more or less stagnant throughout the late Holocene, or, alternatively, as a fertile,udcontinuously occupied and heavily-cultivated alluvial fan in which desertification was a relatively lateudprocess, intensifying only in the mid 4th millennium BP. This paper presents geoarchaeological data fromuda series of test pits in the distal portion of the terminal fan to show that local-scale analysis indicates a farudmore complex interpretation, one shaped by the continuous and non-uniform interaction of aeolian andudalluvial depositional environments, and one that bears substantially on human/landscape dynamics inudthe region. The late Holocene development of the distal fan is examined using proxy data from granulometricudanalysis, Loss on Ignition (LoI) and geochemical analysis, as well as a series of new OSL datesudthat refines the depositional chronology of the region. Ultimately, we show that landscape changeudthroughout the Holocene has been characterized by pronounced variability at the local level not fullyuddescribed by regional scale approaches. While differential aeolian encroachment, non-uniform alluvialudprocesses, and climatic conditions bear significantly on the initial conditions for human occupation,udhuman/environmental processes are ultimately co-evolutionary in nature.