Land Snail Shell Beads in the Sub-Saharan Archaeological Record: When,Where, and Why?

Shell beads are well established in the archaeological record of sub-Saharan Africa and appear as early as 75,000 BP; however, most research has focused on ostrich eggshell (OES) and various marine mollusc species. Beads made from various land snails shells (LSS), frequently described as Achatina, also appear to be widespread. Yet tracking their appearance and distribution is difficult because LSS beads are often intentionally or unintentionally lumped with OES beads, there are no directly dated examples, and bead reporting in general is highly variable in the archaeological literature. Nevertheless, Achatina and other potential cases of LSS beads are present at over 80 archaeological sites in at least eight countries, spanning the early Holocene to recent past. Here, we collate published cases and report on several more. We also present a new case from Magubike Rockshelter in southern Tanzania with the first directly dated LSS beads, which we use to illustrate methods for identifying LSS as a raw material. Despite the long history of OES bead production on the continent and the abundance of land snails available throughout the Pleistocene, LSS beads appear only in the late Holocene and are almost exclusively found in Iron Age contexts. We consider possible explanations for the late adoption of land snails as a raw material for beadmaking within the larger context of environmental, economic, and social processes in Holocene Africa. By highlighting the existence of these artifacts, we hope to facilitate more in-depth research on the timing, production, and distribution of LSS beads in African prehistory.     

Heritage Monitoring Scouts: Engaging the Public to Monitor Sites at Risk Across Florida

ABSTRACT

Along Florida’s nearly 13,000 km of shoreline, nearly 4000 archaeological sites and over 600 recorded historic cemeteries are at risk from climate change impacts including coastal erosion and a 2-metre rise in sea level. In 2016, the Florida Public Archaeology Network (FPAN) created the Heritage Monitoring Scouts (HMS Florida) programme to engage the public in monitoring sites at risk. The programme grew quickly during the first year of operation to include 233 volunteers who submitted 312 monitoring forms. The programme exists beyond the singular act of a volunteer reporting site conditions; across Florida, varied combinations of local partnerships present unique opportunities for programmes, for example, the pilot program at the Guana Tolomato Matanzas National Estuarine Research Reserve. Preliminary outcomes from the first year of HMS Florida and the pilot indicate the programme is effective in public engagement and a powerful management tool for tracking change to sites over time.     

Hydraulic and hydrochemical properties of deep sedimentary reservoirs of the Upper Rhine Graben,Europe

Hydraulic and hydrochemical data from several hundred wells mostly drilled by the oil and gas industry within the four deep carbonate and siliciclastic reservoirs of the Upper Rhine Graben area in France and Germany have been compiled, examined, validated and analysed with the aim to characterize fluids and reservoir properties. Due to enhanced temperatures in the subsurface of the Upper Rhine Graben, this study on hydraulic and hydrochemical properties has been motivated by an increasing interest in deep hydrogeothermal energy projects in the Rhine rift valley. The four examined geothermal reservoir formations are characterized by high hydraulic conductivity reflecting the active tectonic setting of the rift valley and its fractured and karstified reservoirs. The hydraulic conductivity decreases only marginally with depth in each of the reservoirs, because the Upper Rhine Graben is a young tectonically active structure. The generally high hydraulic conductivity of the reservoir rocks permits cross‐formation advective flow of thermal water. Water composition data reflect the origin and hydrochemical evolution of deep water. Shallow water to 500 m depth is, in general, weakly mineralized. The chemical signature of the water is controlled by fluid–rock geochemical interactions. With increasing depth, the total of dissolved solids (TDS) increases. In all reservoirs, the fluids evolve to a NaCl‐dominated brine. The high salinity of the reservoirs is partly derived from dissolution of halite in evaporitic Triassic and Cenozoic formations, and partly from the fluids residing in the crystalline basement. Water of all four reservoirs is saturated with respect to calcite and other minerals including quartz and barite.     

Late Bronze Age Copper Smelting Slags from Luserna (Trentino,Italy): Interpretation of the Metallurgical Process

In the Late Bronze Age, the extractive metallurgy of copper in north‐eastern Italy achieved a peak of technological efficiency and mass production, as evidenced by the substantial number of metallurgical sites and the large volume of slags resulting from smelting activities. In order to define the technological features of the Late Bronze Age metallurgical process, more than 20 slags from the smelting site of Luserna (Trentino, Italy) were fully analysed by means of optical microscopy, X‐ray powder diffraction, X‐ray fluorescence spectrometry and scanning electron microscopy. Three different slag types were identified based on mineralogical and chemico‐physical parameters, each being interpreted as the product of distinct metallurgical steps. A Cu‐smelting model is proposed accordingly.