Sampling for 14C analysis
In the framework of the continuing project for increasing the corpus of 14C dates from Georgia in order to develop a more reliable absolute chronology of the area (see previous reports), to be synchronised with that of the neighbouring regions, dr. Elisabetta Boaretto took part from July 8th to July 15th 2012 to the excavation at Natsargora, where she undertook selective collection of samples for 14C analyses from different contexts, both Kura-Araxes and LB in date, in highly controlled environment. In addition, she also collected samples from the early Kura-Araxes settlement of Treli (Tbilisi region), kindly provided by the excavator, dr. Mikhail Abramishvili (GNM), and from the newly excavated kurgan of the Early Kurgan period at Chincharis Gora near Chabukiani village in Khakheti region, kindly provided by the excavator, dr. Zurab Makharadze (GNM). Like those collected in 2010, 2011, the samples will be analysed at the 14C laboratory of the Weizmann Institute of Science (Rehovot, Israel).
Results from the previous seasons suggest a date around 3000 cal B.C. for the Kura-Araxes settlement at Natsargora (1 sample from Ramishvili's old excavation and two samples from the 2011 Georgian-Italian excavations). On the other hand, a date around 2500 cal B.C. is suggested for Kurgan no. 5 at Bedeni, of the Early Kurgan period.
Sampling for soil micromorphology analysis
Samples for soil micromorphology analysis were collected on the field from July 1st to July 11th by prof. Giovanni Boschian, who will carry out their analysis in Italy, and, after his departure, by the team's archaeologists. Geoarchaeological studies had been started on the Natsargora mound site during the 2011 field season; as in 2011, the main aim of these studies is to elucidate the influence of past human activities on sediment production and deposition, and on the site formation processes, in order to understand the use of the site and of its areas. The soil micromorphological technique can be applied in order to find clues to these issues, because several types of traces of human activity can be put into evidence at microscopic level, including ash, phytoliths, dung remains, trampling, etc.
The cm-sized or finer layers of which the floors are comprised can be studied particularly well at microscopic level, and sequences of traces of past human activities can be found concentrated in the layers that cover them, even if these are rather thin. The extensive application of soil micromorphology can therefore provide invaluable information about the meaning of some features and on the organisation and use of the space within the site.
Samples for micromorphological analyses are usually undisturbed sediment blocklets approximately 9 x 6 x 6 cm that are carved out from excavation profiles or surfaces. The preparation of the samples is carried out in specialised laboratories; after thorough drying, the monoliths are impregnated by polyester resin at low pressure, cut into slices by diamond disks, polished by corundum abrasive and glued on microscope slides. Their thickness is then reduced to 30 micrometres by grinding on corundum. The slides are finally covered by a thin glass slide.
These thin sections can be observed under a standard polarising microscope and described following standard procedures.
After the examination of the 2011 thin sections, this year's work mostly focused on two aspects:
- floor construction and use, mostly as indicators of possible differences in site use between the Early and Late Bronze ages. In this perspective, sequences of prepared floors (including the sediments deposited on them) were sampled, with special attention to a precise determination of their age and cultural attribution. Where available, floor sequences were sampled within the same area of the site. Considering that very few traces of animal husbandry were put into light by the examination of the 2011 thin sections, more efforts were put in testing the hypothesis that animals -if present- were kept outside the settlement, or in dedicated areas.
- earth “walls” and other similar installations that may belong to dwelling features. These installations are mainly crescent-shaped and not more than 20 cm high, often burned, and may represent a residue of higher features that marked the perimeter of roofed areas. The micromorphological sampling was aimed at collecting a number as large as possible of samples from these features, in order to elucidate construction techniques and use.
Samples were also taken from firing installations of different kind, in order to improve the corpus of those collected in 2011.
As a consequence of the excavation of a test sounding at the Eastern limit of the excavation area, in quadrant 099.100b, the original soil on which the settlement was founded was put into light, under a sequence of occupation spanning the EBA and LB periods. The unearthed soil profile is very well preserved on a thickness of about 60 cm, and can be studied with good detail; its characteristics indicate development of forest cover under mild temperate conditions, together with a fast burial of the original surface by human activities.
Fig. 8 shows the W profile of the test pit, including bedrock (1), the forest natural soil (2), and a sequence of cultural levels including the first traces of human activity on the site (3) and some Kura Araxes and LB prepared floors (4; 8) with the location of the soil micromorphological samples taken from it.
Other sampling
Paleobotanical samples collected from both dry-sieving and flotation of different contexts were delivered at the end of the season, together with those collected during the 2011 season and not used for 14C analysis, to dr. Nana Rusishvili (GNM), who will analyse them for publication.
Finally, we also collected a number of samples from a section of the deep sounding spanning the whole remaining sequence (both LB and EB down to the original natural soil) of the Natsargora site for palinological analysis, which we intend to deliver to prof. Eliso Kvavadze (GNM), who kindly agreed to examine them.