A 7000-year record of environmental change: Evolution of Holocene environment and human activities in the Hangjiahu Plain, the lower Yangtze, China

The Hangjiahu Plain in the lower Yangtze is one of the core areas that sustained the flourishment of the Liangzhu Civilization. This study reconstructed Holocene environmental change on the Hangjiahu Plain based on a sediment core collected from the Tangqi ZK-3 location situated on the low-lying Hangzhou-Taihu region of the Yangtze Delta. We applied OSL dating, grain size analysis, pollen analysis, and magnetic susceptibility to reconstruct Holocene environmental change and compared our data with other published results. Our results showed that (i) before ~7.0 ka B.P., the ZK-3 core recorded a strong hydrodynamic force, resulting in the widespread deposition of light grayish silt clay or clayey silt in the region. The climate was warm and humid, and the vegetation was mixed evergreen deciduous coniferous forest. (ii) Between 7.0 and 6.0 ka B.P., the hydrodynamic condition in ZK-3 core became weaker, and the climate remained warm and humid. Although most of the Hangjiahu Plain were still covered by the light grayish silt clay or clayey silt, some higher grounds began to emerge as sea-level rise slowed, which coincided with the development of the Majiabang culture. (iii) Between 6.0 and 4.5 ka B.P., the deposition of yellowish silty clay indicates a shallow-water hydrological environment at ZK-3, as the regional water level was dropping while more land was emerging, which provided a favorable physical environment for the prosperity of the Songze and Liangzhu cultures. The period experienced a drier and cooler climate, with evidence of deforestation. (iv) Between 4.5 and 3.0 ka B.P., the sediments in the ZK-3 core were dominated by light grayish clay, indicative of a return to a deep-water environment with a prolonged waterlogging condition. The climate remained dry and cool with further deforestation. However, the widely distributed yellowish silt clay suggests frequent floods in the region, resulting in a sharp reduction of settlement sites and the eventual decline of the Liangzhu Civilization

Rare Earth Elements Geochemistry of Ceramics Excavated from Tongguanyao Site, China

Rare earth element (REE) compositions in ceramics from the Tongguanyao site (TGY) of China were determined by the inductively coupled plasma-mass spectrometry (ICP-MS) to compare their sources. Total REE concentrations of 14 samples range from 120.9 to 453 mu g.g-1, with an average value of 228.5 mu g.g-1. The inconformity of chondrite-normalized REE patterns suggests that pottery and porcelain have different material sources. The normalized REE patterns indicates similar trends between the raw materials and ceramics in the same period, as a higher concentration of REEs is presented in the ceramics, suggesting that REEs enriched during the production process of ceramics with high temperature. A different chondrite normalized REE pattern between the reticulated soil and ceramics implies that they had not a single source, probably mixed material sources.CPCI-S(ISTP)[email protected]

Hydrological Regime, Provenance, and Impacts on Cultural Development at Changsha Kiln Archaeological Site since 1300 a, Lower Xiangjiang River, China

Changsha kilns were exported to more than 20 countries and regions and were an essential part of the culture in the central Yangtze River during the late Holocene. Reconstructing the hydrological landform and sedimentary history of its surrounding areas (Shizhu) is significant for further constraining any links between regional paleoenvironmental change and the human−land relationship in the lager river valley. To examine paleo−hydrological and provenance evolution, the rare earth element (REE) and trace element ratio from the Shizhuping (SZP) section were analyzed. The SZP section records the paleo−hydrological evolution over 1300 years: river network cutting plain landscape—Shizhu Lake—river floodplain—Shizhu Lake reformation—Shizhu flat. This section was labeled as stages IV to I, respectively. The deposition of stages IV was wind and dust accumulation during the Last Glacial. The provenance of stages III (1288–1094 a.BP) was wasted from the ceramic production process. The layer of stage II (1094–380 a.BP) was in two parts. In stage II−2 (1094–890 a.BP), provenance was dominated by granite. Sedimentary rocks became the source of stage II−1 (890–380 a.BP). In stages I (380 a.BP–), the primary material sources were anthropogenic bedding and weathering erosion deposits around the slope. During the Medieval Warm Period, the climate was warm and humid, and the rising water level of the Xiangjiang River led to the emergence of lakes in the Shizhu area. The migration of northern China into Changsha kiln brought new technology and labor. In the late Five Dynasties, the climate turned dry, and the falling water level of the Xiangjiang River caused Changsha kiln to lose its commercial wharf

Hydrological Regime, Provenance, and Impacts on Cultural Development at Changsha Kiln Archaeological Site since 1300 a, Lower Xiangjiang River, China

Changsha kilns were exported to more than 20 countries and regions and were an essential part of the culture in the central Yangtze River during the late Holocene. Reconstructing the hydrological landform and sedimentary history of its surrounding areas (Shizhu) is significant for further constraining any links between regional paleoenvironmental change and the human−land relationship in the lager river valley. To examine paleo−hydrological and provenance evolution, the rare earth element (REE) and trace element ratio from the Shizhuping (SZP) section were analyzed. The SZP section records the paleo−hydrological evolution over 1300 years: river network cutting plain landscape—Shizhu Lake—river floodplain—Shizhu Lake reformation—Shizhu flat. This section was labeled as stages IV to I, respectively. The deposition of stages IV was wind and dust accumulation during the Last Glacial. The provenance of stages III (1288–1094 a.BP) was wasted from the ceramic production process. The layer of stage II (1094–380 a.BP) was in two parts. In stage II−2 (1094–890 a.BP), provenance was dominated by granite. Sedimentary rocks became the source of stage II−1 (890–380 a.BP). In stages I (380 a.BP–), the primary material sources were anthropogenic bedding and weathering erosion deposits around the slope. During the Medieval Warm Period, the climate was warm and humid, and the rising water level of the Xiangjiang River led to the emergence of lakes in the Shizhu area. The migration of northern China into Changsha kiln brought new technology and labor. In the late Five Dynasties, the climate turned dry, and the falling water level of the Xiangjiang River caused Changsha kiln to lose its commercial wharf

Black carbon and charcoal records of fire and human land use over the past Cheek l 1300 years at the Tongguan Kiln archaeological site, China

To examine fire patterns and landscape evolution in the Xiangjiang River Basin over the past 1300 years, high-resolution charcoal and black carbon (BC, char and soot) records from the Tongguan Kiln archaeological site of historical ceramic production have been analyzed in combination with robust Optically Stimulated Luminescence (OSL) and accelerator mass spectrometry radiocarbon (AMS(14)C) dating, archaeological documents, and paleo-environmental proxies (i.e., magnetic susceptibility, total organic carbon, XRF-derived elemental data, etc.). Throughout history, charcoal and BC have recorded changes in regional land use at the Tongguan Kiln site. Peaks in char and macro-charcoal contents indicate that local smoldering fire occurrences were typical with large amount of fuel used for kilns between 1300 and 1100 years B.P. under wet climate conditions. These peaks coincided with the size of the Tongguan Kiln archaeological site, which led to reduction of forest cover from nearby mountains and activated soil erosion. Subsequently, the frequency of fire activity declined to a very low level between 1100 and 600 years B.P., coupling with the decline of the Tongguan Kiln, and with a warm period in the study region. Over the past 600 years, with sharp growth in population, regional fires increased to an unprecedented scale for land reclamation for dry crop cultivation during a cold period, which in turn resulted in further environmental deterioration. In summary, shifts of fire patterns in the study site over the past 1300 years have been closely related to (1) climate variation; (2) the mode of human land use; and (3) vegetation type and fuel combustion efficiency. There was an interactive, complex relationship between these factors in the Xiangjiang River Basin, and these results suggest that the intensity and pattern of human land use could have further impacts on fire patterns and landscape evolution in response to climatic change of the East Asian Monsoon, in the past as well as in the future

On the Relationship between Holocene Geomorphic Evolution of Rivers and Prehistoric Settlements Distribution in the Songshan Mountain Region of China

This paper deals with the study of Holocene geomorphic evolution of rivers around Songshan Mountain in relation to human frequentation in Prehistoric periods. The investigations were performed by means of an integration of GIS data processing; field surveys and particle size analysis. In 8000–3000 aBP; in the Songshan Mountain Region, large-scale river sedimentation occurred. This increased the elevation of river beds that were higher than today. After 3000 aBP; the upper reaches of the rivers experienced a down cut; while the lower reaches experienced continuing sedimentation. The data on the elevation of prehistoric settlements above the river levels were obtained from Digital Elevation Models (DEMs). These data were corrected according to the evolutionary features of fluvial landforms in order to obtain synchronous elevations above river levels of prehistoric settlements. The relationship between sediment distribution and the Holocene geomorphic evolution was investigated through the statistical analysis of the elevation above the river levels. Outputs from our analyses enabled us to differentiate three evolutionary stages. During the first one, related to Peiligang culture (9000–7500 aBP), populations mainly settled on both hilly relief and high plateaus depending on their agriculture production modes. During the second stage, from Yangshao (7500–5000 aBP) to the Longshan period (5000–4000 aBP), settlements were mainly distributed on mountainous areas and hilly lands to avoid flooding and to develop agriculture. Finally, during the Xiashang culture (4000–3000 aBP), a large number of settlements migrated to the plain area to facilitate trade of goods and cultural exchanges

Holocene fluctuations in vegetation and human population demonstrate social resilience in the prehistory of the Central Plains of China

AbstractArchaeologists and palaeoclimatologists have focused on the impact of climate on the prehistoric civilizations around the world; however, social resilience in the face of the climate change remains unclear, especially during the Neolithic and Bronze Age in the Central Plains of China (CPC). In this paper, we present palynological results from the Dahecun Core, Henan Province, China. Our pollen data indicate a warm and wet climate condition from 9200 to 4000 cal BP, which then switches to a cool and dry climatic condition during the Neolithic-Bronze Age transition (～4000–3600 cal BP). We analyze 14C dates from archaeological sites to demonstrate four episodes of population increase and present vegetation dynamics, determined from available pollen data, to provide evidence for the synchronous shifts in vegetation and human population during the Neolithic. Our results indicate that the aridification in the early Bronze Age did not cause population collapse, highlighting the importance of social resilience to climate change. The pollen, radiocarbon dates and archaeobotanical records from the CPC provides new evidence that supports the claim that the development of agriculture and complex societies, under the stress of a dry climate, set the stage for the dramatic increase of human population around 3800–3400 cal BP

Black carbon and charcoal records of fire and human land use over the past Cheek l 1300 years at the Tongguan Kiln archaeological site, China

To examine fire patterns and landscape evolution in the Xiangjiang River Basin over the past 1300 years, high-resolution charcoal and black carbon (BC, char and soot) records from the Tongguan Kiln archaeological site of historical ceramic production have been analyzed in combination with robust Optically Stimulated Luminescence (OSL) and accelerator mass spectrometry radiocarbon (AMS14C) dating, archaeological documents, and paleo-environmental proxies (i.e., magnetic susceptibility, total organic carbon, XRF-derived elemental data, etc.). Throughout history, charcoal and BC have recorded changes in regional land use at the Tongguan Kiln site. Peaks in char and macro-charcoal contents indicate that local smoldering fire occurrences were typical with large amount of fuel used for kilns between 1300 and 1100 years B.P. under wet climate conditions. These peaks coincided with the size of the Tongguan Kiln archaeological site, which led to reduction of forest cover from nearby mountains and activated soil erosion. Subsequently, the frequency of fire activity declined to a very low level between 1100 and 600 years B.P., coupling with the decline of the Tongguan Kiln, and with a warm period in the study region. Over the past 600 years, with sharp growth in population, regional fires increased to an unprecedented scale for land reclamation for dry crop cultivation during a cold period, which in turn resulted in further environmental deterioration. In summary, shifts of fire patterns in the study site over the past 1300 years have been closely related to (1) climate variation; (2) the mode of human land use; and (3) vegetation type and fuel combustion efficiency. There was an interactive, complex relationship between these factors in the Xiangjiang River Basin, and these results suggest that the intensity and pattern of human land use could have further impacts on fire patterns and landscape evolution in response to climatic change of the East Asian Monsoon, in the past as well as in the future.</p