Radiocarbon anomalies suggest late onset of agricultural intensification in the catchment of the southern part of the Yangtze Delta, China

Abstract

5Holocene sediments from the southern part of the delta are unevenly distributed through 6 time. Two clusters of dates --in sediments ca. 9,000-7,000 cal. BP and ca. 3,000-1,000 cal. BP 7--most likely indicate two periods of intensive erosion and redeposition of organic materials. 8The older of the two clusters may have been associated with a marked episode of marine 9 transgression, whereas the younger cluster could reflect increasing levels of human 10 disruption of soils and sediments in the catchment. A relatively late increase in 11anthropogenic soil erosion supports recent archaeological evidence that, following its early 12Neolithic origins, agricultural expansion and intensification occurred later on the southern 13Yangtze Delta than previously thought.14 15

Pollen and non-pollen palynomorph analyses of Upper Holocene sediments from Dianshan, Yangtze coastal lowlands, China: Hydrology, vegetation history and human activity

“…The Dianshan farming phase is of considerable interest as it seems to be the last of the kind of shifting agriculture used in the Yangtze lowlands since the Neolithic, as its structure is similar to that of earlier agricultural episodes (Okuda et al, 2003;Zong et al, 2007;Innes et al, 2009). It therefore agrees with Long et al (2016)'s view that agricultural intensification was late coming to parts of the lower Yangtze lowlands. Its marginal wetland location might have limited the possible intensity of rice farming.…”

“…The data from the Dianshan core, with high algal frequencies, indicates that eutrophication of lakes in the Taihu plain is not just a modern occurrence, but has been an important process since soon after their creation after 3000 cal. yr BP (Tao et al, 2006), prompted by high levels of agricultural activity and the erosion of nutrient-laden soils into the lakes in the last two and a half millennia, from the time of the Eastern Zhou culture onwards (Hori et al, 2001;Hosner et al, 2016;Long et al, 2016).…”

“…2400 cal. yr BP at several Yangtze Delta sites (Atahan et al, 2007a, b;2008;Itzstein-Davey et al, 2007c), and adjacent higher areas (Ma et al, 2016), and are a reliable cultural marker, often coupled with the inwash of clastic material from eroded soils (Long et al, 2016). Itzstein-Davey et al…”

“…1200 cal. yr BP (Long et al, 2016). A renewed intensification of farming occurred after about 800 cal.…”

Lateglacial And Early Holocene Environments And Human Occupation In Brandenburg, Eastern Germany

“…It turns out that the 14 C dates in the section are probably older than their depositional contexts. Anomalies are not rare in 14 C dating (Long et al 2016) and one in twenty radiocarbon dates can be expected to be either younger or older than its age of deposition (Bronk Ramsey 2009). In any case, introducing quadratic regression to focus on the overall rate of deposition helped establishing a model in which the influence of single anomalous datings is minimized.…”