SA HUYNH REGIONAL AND INTER-REGIONAL INTERACTIONS IN THE THU BON VALLEY, QUANG NAM PROVINCE, CENTRAL VIETNAM

Around 500 BC, the introduction of iron working technology caused radical changes in social structure in both mainland and insular Southeast Asia. The most important phenomenon, which had strong impacts in all aspects of life, was the transformation from small and egalitarian to large and complex societies. This complexity laid the foundations for the emergence and development of early states in the area. The causes and dynamics of these processes were various in nature and included both internal and external elements. Using site and artefact distributions in the Thu Bon Valley, one of the largest and most fertile riverine areas in the whole of central Vietnam, we examine the nature and evolution of regional and inter–regional interaction between Sa Huynh communities and the outside world, especially with the Han Chinese, the Dong Son of northern Vietnam, and contemporary cultures in South and Southeast Asia

SA HUYNH REGIONAL AND INTER-REGIONAL INTERACTIONS IN THE THU BON VALLEY, QUANG NAM PROVINCE, CENTRAL VIETNAM

Around 500 BC, the introduction of iron working technology caused radical changes in social structure in both mainland and insular Southeast Asia. The most important phenomenon, which had strong impacts in all aspects of life, was the transformation from small and egalitarian to large and complex societies. This complexity laid the foundations for the emergence and development of early states in the area. The causes and dynamics of these processes were various in nature and included both internal and external elements. Using site and artefact distributions in the Thu Bon Valley, one of the largest and most fertile riverine areas in the whole of central Vietnam, we examine the nature and evolution of regional and inter–regional interaction between Sa Huynh communities and the outside world, especially with the Han Chinese, the Dong Son of northern Vietnam, and contemporary cultures in South and Southeast Asia

Dating Thach Lac: cryptic CaCO3 diagenesis in archaeological food shells and implications for C-14

In many locations around the world, shell radiocarbon dates underpin archaeological research. The dating of shell brings the chronological relationship between the sample and target event (e.g., hunting and food preparation) into congruence, while shells are valuable geochemical proxies for understanding past climate dynamics and environments. However, this information can be lost as the shell, composites of biopolymers and carbonate minerals (mostly calcite and or aragonite), undergo diagenetic alteration. While studies into Pleistocene-age carbonates are common in the radiocarbon literature, there has been little research into the impact of alteration on Holocene-age shells used to interpret recent societal developments. The limits of our understanding of these diagenetic changes became evident when dating Placuna placenta (naturally calcitic) and Tegillarca granosa (naturally aragonitic) shells from the site of Thach Lac in Vietnam. These shells returned ages significantly younger than associated charcoal and terrestrial bone at the site, but standard tests for secondary recrystallization (XRD and staining techniques) did not indicate any alteration. Further investigation revealed that cryptic recrystallization (i.e., of the same crystal structure) had occurred in both the calcite and aragonite shells. This finding suggests recrystallization may have an undetected impact on some shell radiocarbon dates

Dating Thach Lac: cryptic CaCO3 diagenesis in archaeological food shells and implications for 14c

In many locations around the world, shell radiocarbon dates underpin archaeological research. The dating of shell brings the chronological relationship between the sample and target event (e.g., hunting and food preparation) into congruence, while shells are valuable geochemical proxies for understanding past climate dynamics and environments. However, this information can be lost as the shell, composites of biopolymers and carbonate minerals (mostly calcite and or aragonite), undergo diagenetic alteration. While studies into Pleistocene-age carbonates are common in the radiocarbon literature, there has been little research into the impact of alteration on Holocene-age shells used to interpret recent societal developments. The limits of our understanding of these diagenetic changes became evident when dating Placuna placenta (naturally calcitic) and Tegillarca granosa (naturally aragonitic) shells from the site of Thach Lac in Vietnam. These shells returned ages significantly younger than associated charcoal and terrestrial bone at the site, but standard tests for secondary recrystallization (XRD and staining techniques) did not indicate any alteration. Further investigation revealed that cryptic recrystallization (i.e., of the same crystal structure) had occurred in both the calcite and aragonite shells. This finding suggests recrystallization may have an undetected impact on some shell radiocarbon dates

Dating Thach Lac: cryptic CaCO3 diagenesis in archaeological food shells and implications for C-14

In many locations around the world, shell radiocarbon dates underpin archaeological research. The dating of shell brings the chronological relationship between the sample and target event (e.g., hunting and food preparation) into congruence, while shells are valuable geochemical proxies for understanding past climate dynamics and environments. However, this information can be lost as the shell, composites of biopolymers and carbonate minerals (mostly calcite and or aragonite), undergo diagenetic alteration. While studies into Pleistocene-age carbonates are common in the radiocarbon literature, there has been little research into the impact of alteration on Holocene-age shells used to interpret recent societal developments. The limits of our understanding of these diagenetic changes became evident when dating Placuna placenta (naturally calcitic) and Tegillarca granosa (naturally aragonitic) shells from the site of Thach Lac in Vietnam. These shells returned ages significantly younger than associated charcoal and terrestrial bone at the site, but standard tests for secondary recrystallization (XRD and staining techniques) did not indicate any alteration. Further investigation revealed that cryptic recrystallization (i.e., of the same crystal structure) had occurred in both the calcite and aragonite shells. This finding suggests recrystallization may have an undetected impact on some shell radiocarbon dates

Ru Diep and the Quynh Van culture of central Vietnam

Excavations in 2015 at the site of Ru Diep in north-central Vietnam (Ha Tinh Province) raise significant questions about the transition into the Neolithic in this region, more than 5000 years ago. The material culture from the site reveals a mixture of both pre-Neolithic (Quynh Van culture) and Neolithic elements, in a shell mound context. The C14 dates for the site suggest that the surviving layers were deposited between outer limits of 3200 and 2900 cal. BC, but Bayesian analysis indicates a likely accumulation in less than 50 years. This date is almost one millennium older than expected for Neolithic-related materials in north-central Vietnam.The research of Peter Bellwood and Philip Piper was funded by ARC Discovery Project Grant No. 140100384

Ru Diep and the Quynh Van culture of central Vietnam

Excavations in 2015 at the site of Ru Diep in north-central Vietnam (Ha Tinh Province) raise significant questions about the transition into the Neolithic in this region, more than 5000 years ago. The material culture from the site reveals a mixture of both pre-Neolithic (Quynh Van culture) and Neolithic elements, in a shell mound context. The C14 dates for the site suggest that the surviving layers were deposited between outer limits of 3200 and 2900 cal. BC, but Bayesian analysis indicates a likely accumulation in less than 50 years. This date is almost one millennium older than expected for Neolithic-related materials in north-central Vietnam