Armenia

The Ararat valley in Armenia sits between the Gegham mountains to the east and the impressive volcanic edifices of Mt Ararat in Turkey to the west.  The valley has been an important pathway for both population migration and for trade routes over the last three millennia.  During the middle Ages, and particular between about 500AD and 1500AD the valley saw the rise and fall of the great medieval cities such of Dvin and Artashat.

In early October Tim Raub and I were invited to join Dr Fanny Bessard and Dr Paul Churchill as part of a pilot study of the valley to ascertain if there were suitable records to investigate the role of climate, environmental change and natural hazards in the history of the country. 

The Ararat valley today is an extensively cultivated valley that in the autumn provides a bounty of both fruit and vegetables.  These come at a price however, and that price is the supply of water.  The Aras river, while a significant feature of the valley, can by no means supply all the necessary water for cultivation.  This has to come through channels and pipes from the nearby mountains and from groundwater.  The other piped resource that is in use everywhere is the supply of natural gas.  Unlike many countries, the pipes for this are all above ground, a safety feature built into the urban and rural structures as a defence mechanism for living in an earthquake zone.

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Our first tasks at the now ruined city of Dvin was to determine the environment and possible original reasons as to why the town was founded at this particular location.  There is evidence of site occupation stretching back to at least early bronze age as the site stands proud of the surrounding landscape.  Close inspection revealed a bedrock base that is likely a gravel terrace remnant of the old piedmont surface extending from the mountains to the east.  This has been dissected in parts by a series of river channels which today have either dried up or been modified to harness the water for irrigation purposes. While Tim mapped the geology, I undertook frequency domain electromagnetic surveys in the hunt for the channels and their relationship to the outside walls of the old city. The results were combined with digital terrain and photographic models that show great promise for our future work.

Armed with the knowledge that water supply from the uplands likely played an important controlling factor in both rural and urban centres we moved our investigation up to the hills. Immediately to the east the geology consists of mainly sedimentary rocks and in particular Permo-Triassic limestone  (more on this later). To the north east however, the geology quickly gives way to igneous complexes associated with the numerous volcanic centres in the region.   

Permo-Triassic Boundary

While the climate, and thus rainfall patterns are similar, these different geologies manifest themselves in very different hydrology and scenery. On the sedimentary rocks, fast flowing but ephemeral streams erode steep valley sides whereas the igneous terrain tends to a rolling landscape with more sustained overland flow of streams and rivers.  This means no way of capturing the water in the south in reservoirs, rather the natural springs have to be tapped at source.  However, in the north the hunt is on for where water storage schemes might have been built.  Means for the transport of water is in evidence everywhere.  Leets run parallel to many hillsides and mark the stark contrast from barren land above the leets to lush agricultural land below.  Evidence of buried water conduits in the form of clay pipes of all manner of size and shape have been unearthed from highland villages to the towns across the valley floors. Tracing these will be a priority for future work and trying to understand the pattern of distribution and timing of their construction and demise could be crucial to an understanding of the history. For example, what happened to them when earthquakes struck?

Temple of Garni

So back to that geology.  Tim had done his home work and knew about a few sites that he thought worthy of visit.  The first was where the Azat river cut down through the basalts beneath the Temple of Garni.  The temple dates back to the first century AD and has survived transformation and use through many different religions.  The columnar basalt is quite something else which blew us away totally.  This has to be one of the most spectacular basaltic exposures in the world!

The second site was in the sedimentary sequences to the south and when approached from the southern road out of Lake Sevan you are confronted by a sudden drop-off into the steep limestone valleys that reveal a 1200m section of limestone and calcareous shales with hues from pink to cream that represent one of the best exposures of the Permian to Triassic mass extinction event anywhere. The extent of the exposure is quite remarkable both laterally and in the vertical transition.  Great student mapping projects to be had here!   

The third site he wanted to visit was to the east at Lake Sevan.  This large upland lake sits along the Spitak fault that marks the juxtaposition of ophiolite complexes to the east with the basalt and sedimentary sequences that lead down to the Ararat Valley.  The fault, as with many other ones in Armenia, is still highly active, a feature of the region that is felt on a regular basis with significant earthquakes.  The last major of these had an epicentre further north along this fault zone that struck with a magnitude 6.8 event in 1989 killing over 30,000 people. Understanding more about the timing of earthquakes could help our archaeological studies and thus we needed to find sites with long environmental records that were punctuated by features that showed the earthquake record.  The delta on the northern river inlets gives just that kind of section with what appears to be a series of down-faulted land surfaces in a cyclic and fairly uniform sequence.  This should provide just the kind of record we need for future detailed study.

Tim at the Sevan section of repeat cycles

Armenia has so much to offer in way of study sites both geologically and archaeologically.  The people were great (especially thanks here to Drs Babajanyan and Pavel at the National Archaeological Inst), the food was great and the wine was great.  Now for the big grant application to allow us to return to study the interplay between geology and archaeology.