Global and regional context/importance:
Recent improvement in ice core related paleoclimate methodologies driven by technological innovations has created new opportunities to reconstruct regional paleoclimate and environmental conditions from Alpine glaciers that were proximal to major foci of past human settlement and activity. This shift in research paradigm away from polar ice sheets greatly expands the applicability of ice-core paleoclimate and anthropogenic pollution data for understanding climate- and human-driven environmental change. Similarly, human macro-economic trends and their impact on the global environment cannot be appreciated in detail from historic pollution deposited at the poles. Therefore, in the last two decades ice cores have been extracted from mountain glaciers, mostly in the mid-latitudes of the planet. This has coincided with a huge expansion in cutting-edge analysis of historic climate, environmental and historic pollution evidence from lake sediment cores, ombrotrophic peat cores, fluvial sediments, speleothems (for temperature and pollution) and other records.
Since 2010, new approaches to identify annual layers in ice cores have been developed and perfected by CCI, University of Maine. This has allowed the analysis at ultra-high resolution of climate phenomena and markers of human-related environmental, economic and macro-societal change in close proximity to the principal regions of human activity.
The unique circumstances of the Caucasus region will provide a unique record of the historic interplay between climate change and human action since the Last Glacial Maximum. The current availability of historic ice, glacial moraine, lake, peat, fluvial and archaeological records provide an unprecedented opportunity for the integrated analysis of the different climate, environmental and anthropogenic pollution records with archaeological and historical evidence. Correlating multiple types of geo- archives and archaeological evidence will enable the analysis of diverse climatic, environmental and anthropogenic markers both over the long durée since the last glacial maximum and during shorter periods of rapid climate- and social change since the Bronze Age.
The project represents one of a series of historic ice core and related palaeo-environmental/historic human pollution projects around the mid latitudes of the planet. The Colle Gnifetti Historical ice core covered the region of NW Europe, W Europe and NW Africa. This Caucasus project will cover climate and pollution evidence from the central-eastern Mediterranean, the Black Sea, Anatolia and the Middle East. Other cores (also taken by the CCI, University of Maine) from Mount Everest and the Pamirs cover the Himalayas and the Indian sub-continent to Eastern Asia. As such, this Caucasus project represents the key missing (and possibly the highest potential integrated record) for a critically important region for historic human action among the mid-latitude ice-core projects, and is of global importance of itself and as one of the wider mid-latitude studies.
Rationale for Interdisciplinary Integrated Analysis and Synthetic Interpretation
A combined regional ice-core record, will provide an unprecedented climate and ultra-high (annual) resolution record of both historic climate change and the impact of human macro-economic (metal-related) and societal trends on the environment for the Caucasus region. It should also capture a record of volcanic activity from the central Mediterranean and Aegean Sea; and map past atmospheric pathways for historic pollution signals at different times from the central and eastern Mediterranean, Anatolia and the Black Sea region.
In order for us to be able to differentiate historic local/regional metalworking/macro-societal events in Colchis/Svaneti from pollution arriving from more distant regions (e.g. the Balkans, potentially the Laurion Athenian silver mines, Cyprus, Anatolia), we need to be able to compare the ice core record with peat/lake core records, which usually produce more local pollution profiles. Importantly, however, the peat and lake core bulk samples are also large enough to allow for analysis of isotopes which can, to a certain extent, identify local and foreign pollution signals. The peat and lake cores can also provide the pollen profiles to investigate historic landscape change and trends in cultivation/landscape management so that we can place this agricultural evidence alongside the evidence of the metal economies from the historic pollution.
The survey and dating of the metalworking sites in the Svaneti region and western Georgia are necessary to gain further chronological resolution on trends in the scale and date of mining and smelting of different metals in the same region as the different climate and palaeo-environmental archives. This will allow us to differentiate pollution derived from local or longer-distance sources. Again, selected isotope analysis of the smelting evidence will assess ore origins.
The archaeological survey and palaeoenvironmental research on the Georgian coast of the Black Sea and the “Colchis Plain” will document the landscape changes during the late Holocene, influenced by sea level change, tectonics and change in the sedimentation levels of major rivers (Enguri, Rioni, Kulevi, Supsa). Reconstruction of changes in the palaeo/historic landscape forms the key component for understanding the human settlement pattern, local economy and wider human social networks through time, from the period of Bronze Age Colchis to the present.
The synthetic analysis and interpretation phase, incorporating all known contexts from archaeological and historical sources is essential to provide meaning and context to the various proxy data, whether for known historic volcanic eruptions, disease events, socio-political events/periods and economic innovations. The contribution of historians is essential in this phase of the project.
Potential Component Projects:
It is intended that the aims of the overall strategic project will be met by the conduct of different component projects, and a model synthesis project to maximize insights from the integration of different forms of evidence. This way the different component projects can progress, share research data and publish as compartmentalized projects, to satisfy funding and state-review deadlines, while also contributing data and perspectives to the overall integrated project results.
Ice Core(s)
- Ice core records from the Adishi plateau in Svaneti, Kazbegi and other sites. The individual ice core records will be analyzed using stable water isotopes, ion chromatography, solution based ICP-MS, hyperspectral imaging and targeted direct LA-ICP-MS on ice for annual layer markers, indicators of volcanic, dust storm and human pollution events. A developed time scale will be corroborated using micro-particulate radiocarbon-dating; correlation of temperature and precipitation proxies; and historic pollution evidence as proxies for human macro-societal/economic impact on the environment and pandemic disease events with other regional archives. Climate re-analysis datasets will be used for Flexpart or HYSPLIT modelling to help refine source emission parameters for historic pollution and atmospheric airmass signals.
Peat Core(s)
- An ombrotrophic peat core record (from western Georgia). This record will comprise a series of overlapping cores from the same location: one core for chronostratigraphy using radiocarbon dates; one core for tephra analysis; one core for pollen (environmental change)/sediment accumulation rates; one core for climate change – Carbon 13 analysis (temperature proxy in peat/sediments); one core for historic pollution analysis using PXRF, then ICP-MS, and selected isotope analysis for ore sourcing, for metal economy and macro-societal change data.
Lake Core(s)
- Lake core(s). Again, ideally there will be a series of overlapping cores. Again: one core for chronostratigraphy using radiocarbon dates and layer-counting if varves; one core for tephra analysis; one core for pollen (environmental change)/sediment accumulation rates; one core for climate change – Carbon 13 analysis (temperature proxy in peat/sediments); one core for historic pollution analysis using PXRF, then ICP-MS, and selected isotope analysis ore sourcing, for metal economy and macro-societal change data.
River Palaeochannel Sediments
River sediments from the outcrops, as well as river palaeochannel sediment cores in western Georgia can provide unique information on environmental changes, caused by natural (climatic, paleoseismic) and anthropogenic factors (historic metal pollution, landscape change/erosion/colluviation due to agriculture). Reconstructed sedimentation rates of these rivers (originating in the Caucasus mountain glaciers) will provide unprecedented details on regional Holocene warming and cooling events and erosion linked to agriculture in the different climatic circumstances, and metal-pollution levels linked to mining/smelting and pollution of waterways. It is expected that river/palaeochannel sediment cores will provide data from the last two millennia.
Archaeological Survey and dating programmes
- Archaeological survey and dating programme of metalworking/smelting sites in Svaneti/western Georgia, to be achieved through survey collection of slag/smelting deposits and radiocarbon dating of material from excavated sites. A sample will also be analyzed for isotope profiles of ores.
- Archaeological survey and dating of settlement mounds and other settlement evidence through geoarchaeological and other means.
Glacial Moraines
- A programme of dating glacial moraines is also envisaged using the state-of-the art Be10 dating method, to reconstruct high-resolution regional glacier responses to climate change drivers from the last glacial maximum to the present. Developed data will help to connect regional responses in the Caucasus to global climate shifts.
Building a Dendrochronological Sequence for the region
Some sporadic work has been done on building dendrochronological sequences in the region. The project can explore the potential for the creation of dendro-sequences for certain periods, depending on availability. Wood in historic standing buildings represents one area of potential, especially for the exploration of the impact of climate change over the last millennium.