Reassessing the northern limit of maize consumption in North America: stable isotope,plant microfossil,and trace element content of carbonized food residue

In combination, the analysis of carbonized food residue for stable C and N isotopes, elemental composition, and plant microfossils (phytoliths and starch granules) offers a powerful tool for understanding patterns of prehistoric maize (Zea mays) consumption in small-scale societies. Using this approach, we conclude that maize was more widely consumed in North America than previously suspected. Between ∼AD 700 and 1600, despite little or no archaeological evidence of gardening, corn was a widespread component of diet on the eastern Canadian prairies. This pattern, furthermore, extended into the adjacent boreal forest at about the same time. However, carbon (δ¹³C) and nitrogen (δ¹⁵N) values on food residue samples vary widely, suggesting significant overall dietary differences from one region to the next. Analysis of a subset of residue samples for elemental composition (using ICP-OES [inductively coupled plasma–optical emission spectrometry]) may help identify broad trends in the provenience of foods consumed at these sites.     

A Comparison of Three Methods for the Extraction of Phytoliths from Sediments

This paper compares three methods commonly used to extract fossil phytoliths from sediments. A basic procedure using heavy liquid flotation and oxidation is compared with two other procedures across a range of sediment types commonly encountered in archaeological studies. The three procedures are: (1) a heavy liquid flotation method (HLF); (2) a burning method (POW); and (3) another heavy liquid flotation method (HLFPol) similar to HLF, but adapted to allow the extraction of pollen and spores as well as phytoliths, within a single process. Comparisons of the resulting output using these three techniques for phytolith extraction show that different methods can produce different results, and therefore basic techniques should be modified according to the characteristics of the sediments for which they are used. While all the techniques showed similarities in assemblage results, there were problems associated with disaggregation and effective separation of light and heavy fractions, in particular with the POW procedure. The evidence suggests that morphotype selection occurred both within the physical sorting process and in the process of inverting slides to shed excess residue; in both cases it is difficult to suggest a solution to the problem. The results show clearly that the advantages gained by using the POW procedure are largely outweighed by the problems encountered with its use, and because of possible size/shape selection, it is not recommended for general extraction procedures. The heavy liquid flotation procedures, on the other hand, are shown to produce more concentrated residues with higher levels of clarity and less potential than the POW procedure for sample bias. The use of a non-toxic heavy liquid, sodium polytungstate, now allows the process to be used in relative safety. It is recommended that analysts use heavy liquid flotation procedures with chemical treatments specific to sediment requirements.     

Palaeochannels of the Balkh river (northern Afghanistan) and human occupation since the Bronze Age period

In 2002, the unexpected discovery of Hellenistic architectural blocks, buried in 8 m of alluvium, found displaced in a former bed of the river of Balkh, brought about a programme of surveys and excavations under the aegis of the French Archaeological Mission in Bactria. The geoarchaeological side of the programme focused on the drawing of a regional geomorphological map then on the identification, mapping and dating of the palaeochannels of the river of Balkh. We established the chronology of several fluvial channel generations by association with archaeological settlements of different eras (Bronze Age, Bactro-Achaemenid period, Kushan period, Islamic period) and with optically stimulated luminescence dating carried out on alluvium deposits. The present riverbed leading up to Aqcha was formed during the Islamic period. We suspect the primary agent of this change in the river channel to, be tectonic activity and the activation of a blind fault crossing the floodplain. We identified a northern Bactro-Achaemenid aqueduct, currently located in the desert area separating the plain of Balkh from the Amu Darya.     

Geoarchaeology of Ancient Aulis (Boeotia,Central Greece): human occupation and Holocene landscape changes

This article presents the results of a coring operation which brought to light new evidence for the evolution of the coastal plain of Aulis (Boeotia, Central Greece) in the Holocene. Thanks to Homer, Aulis is best known as the gathering point of the Achaean fleet before it sailed to Troy and a sanctuary of the goddess Artemis. Ancient sources and archaeological evidence suggest the presence of an ancient marine bay, potentially used as a harbor. In the course of investigation, we drilled two cores, to a maximum depth of 4.20 m in the marshy lowlands and performed mollusc and micro-paleontological identifications, laser grain size analyses, and magnetic susceptibility measurements in order to reveal the facies evolution of the area. We obtained a chronostratigraphy sequence through a series of seven AMS ¹⁴C radiocarbon dates. Our study shows that the area was affected by a shallow marine incursion from the first half of the 6th millennium BC and gradually turned into a succession of shallow marine/lagoon environments from ca. 5000 cal. BC to the 2nd Century AD, and into a confined lagoon environment during the Roman and Byzantine periods.