Ancient trash mounds unravel urban collapse a century before the end of Byzantine hegemony in the southern Levant

Abstract

The historic event of the Late Antique Little Ice Age (LALIA) was recently identified in dozens of natural and geological climate proxies of the northern hemisphere. Although this climatic downturn was proposed as a major cause for pandemic and extensive societal upheavals in the sixth–seventh centuries CE, archaeological evidence for the magnitude of societal response to this event is sparse. This study uses ancient trash mounds as a type of proxy for identifying societal crisis in the urban domain, and employs multidisciplinary investigations to establish the terminal date of organized trash collection and high-level municipal functioning on a city-wide scale. Survey, excavation, sediment analysis, and geographic information system assessment of mound volume were conducted on a series of mounds surrounding the Byzantine urban settlement of Elusa in the Negev Desert. These reveal the massive collection and dumping of domestic and construction waste over time on the city edges. Carbon dating of charred seeds and charcoal fragments combined with ceramic analysis establish the end date of orchestrated trash removal near the mid-sixth century, coinciding closely with the beginning of the LALIA event and outbreak of the Justinian Plague in the year 541. This evidence for societal decline during the sixth century ties with other arguments for urban dysfunction across the Byzantine Levant at this time. We demonstrate the utility of trash mounds as sensitive proxies of social response and unravel the time–space dynamics of urban collapse, suggesting diminished resilience to rapid climate change in the frontier Negev region of the empire.

Climate stability and societal decline on the margins of the Byzantine empire in the Negev Desert

“…Sheep and goat samples were obtained from archaeological assemblages in the recently re-excavated sites of Subeita (Shivta), Nessana (Nitzana) and Elusa (Halutza). Chronological assignments (Byzantine vs. Islamic period) were made based on ceramic and coin typologies and confirmed using associations to radiocarbon-dated contexts (Elusa: Bar-Oz et al 25 ; Shivta: Tepper et al 12 ; Nessana: forthcoming). Material from transitional periods was not included.…”

“…Archaeological proxies (such as dates of abandonment layers and diets of animals) can be used to investigate the effects of any climatic or geomorphological shifts on patterns of human habitation in the Negev Desert. Bar-Oz et al 25 dated the collapse of the urban management of the Byzantine capital city of Elusa to the 6 th century CE, and correlated this event to the contemporary Late Antiquity Little Ice Age in Europe and the Justinian plague outbreak in 541 CE 26 . In their paper "Signs from a green desert", Ramsay and Tepper analysed the contents of pigeon dung preserved in the dovecotes near Shivta to characterize the local environment around the settlement 27 .…”

A model-based approach to the tempo of “collapse”: The case of Rapa Nui (Easter Island)

“…Our results demonstrate that the tempo plot technique has wide applicability for quantifying the timing and rate of change of archaeological processes, in particular declines or cessation of activities associated with purported 'collapse' events and provides a viable alternative to the more common approach of using summed probability distributions of radiocarbon dates. Tempo plots can also provide a useful extension of more common Bayesian approaches and offer ways to better characterize and quantify similar case studies around the world, such as the rate of decline at various Maya political centers (e.g., Ebert et al, 2017Ebert et al, , 2016Hoggarth et al, 2016) and other areas (e.g., Bar-Oz et al, 2019;Carter et al, 2019;O'Shea et al, 2019).…”

Radiocarbon dating the end of urban services in a late Roman town

“…Other archaeological evidence shows that the town continued to be inhabited nevertheless. Bar-Oz et al (2) argue that the dump dates document the end of long-standing city services, a turning point toward a downward trend. The Negev towns are part of the bigger discussion about the collapse of the mighty eastern Roman Empire and its thriving cities: archaeological arguments for urban decline were made as early as 1954, but those findings were published in Russian (8) and took decades to generate mainstream research in the West.…”

“…A few have pointed to these exogenous shocks from the climate and disease as critical factors weakening the empire en route to Rome's final fall (17,18), while others deny their importance in favor of traditional political, social, and military causes (19,20). Hence the importance of absolute dating ancient landfills (2). While military defeats involving massive death and destruction by fire can be relatively easy to observe archaeologically, economic and urban deterioration leaves more subtle material traces, especially in major ancient cities such as Constantinople (Istanbul) or Alexandria, where modern construction obliterates the delicate residue of ancient decline.…”