Vardzia Caves and the Geoscientist in Me
This summer we planned to visit the country of Georgia, located at the intersection of Eastern Europe and Western Asia. We stayed there for two weeks and explored the natural beauty as well as some important historic marvels of Georgia. This country is small in size but it’s a giant in terms of natural beauty and history. Georgia is rich in historical languages and communities like Svaneti and Tusheti.
We visited one of the most iconic cave cities of the world, The Vardzia Caves. This cave dwelling is located on the Erusheti mountain in the Samtskhe Javakheti region of Southwestern Georgia, close to the Turkish and Armenian borders. We stayed in the city of Borjomi and did a day trip to the caves.
The cave city of Vardzia was a part of the defense system of the Kingdom of Georgia from the constant threat of the Mongol Empire. Vardzia was built by King Tamar in the 12th century. King Tamar was a women but was crowned as a king because in the medieval times the word queen was reserved for the wives of the kings. She ordered to build the underground fortress under the Erusheti mountain to save the people of her kingdom from the invading Mongols.
This underground fortress had a throne room, a reception chamber, a meeting room, a bakery, a forge chapel and a huge church. I was a complex of 13 levels and over 600 rooms. There was a tunnel that started at the Mtkvari River and went all the way to a secret entrance to the fortress. The land was fertile and the monks had developed a self sustaining system of irrigation and farming on the terraces to produce their own food. They had about 25 wine cellars containing 185 wine jars. They had ample to eat and drink and that made it invincible from the outside invasions.
In it’s hay days this fortress saved the people of the Kingdom of Georgia from the outside invasions. Whereas, only 100 years after its construction in 1283, a devastating earthquake destroyed more than two-thirds of the city and the remaining caves that were once hidden became visible. According to one legend, there were 365 rooms in Vardzia, so king Tamar could move to a new room each day throughout the year so her exact location would always remain unknown for invaders.
Vardzia is an excellent example of a cultural landscape, in which human activities, natural, geological, and geomorphological processes, are not only connected but are interdependent and this fact made it an historic archeologic relic from the 11th century.
The Vardzia monastery is cut and carved in volcanic and pyroclastic rock formations, Gillespie & Styles (1999). The area has volcanic and pyroclastic rocks of the Upper Miocene — Lower Pliocene Goderzi Formation. The whole sequence is a result of several volcaniclastic and pyroclastic falls, and is made up of chemical lava compositions. There are two main discontinuity systems, the first (sub vertical) due to cooling of the volcaniclastic sequence and a second one (locally parallel to the slope face) mainly due to stress release caused by the valley erosion. Vardzia slopes are the final result of local seismicity, different volcanic falls, erosion, and deposition cycles of the Mtkhvari river.
The geophysicist in me forced me to do some research on the geologic and tectonic history of the caves and this is what I got.
Basically, the area is constructed by subaerial volcanogenic-sedimentary rocks — tuff-breccias, sandstones, argillites and marls, and is also covered with thick series of dolerites and basalts of the Quaternary age. This rock system is subdivided into two big parts: the lower part with the thickness of 200–250 m is mainly dark, weakly cemented coarse material of hyperstenic composition. Above this part there is a 20–80 m thickness whitish layer. It is slightly sintered fine-grained tuff flow. Tuffs of the Vardzia flow are soft rocks, they make fingers dirty although it is impossible to crash them by hand. Their color changes from pink to light grey-white. Petrographically these tuffs can be divided into three parts: lithoclastic, porphiroclastic and cementing materials. Tectonic structure of the Vardzia region is very complex . There are two types of tectonic faults:- 1) faults provoked by regional geological processes and 2) the faults conditioned by local gravitation phenomena. The basic tectonic structure of the area is a deep fault, that goes along the Mtkvari river gorge. Along the fault the Vardzia area is divided in two large geoblocks: a western block — Vardzia (Erusheti) and an eastern — Javakheti. Apparently, the centre of Vardzia destructive earthquake in 1283 was located right along this fault.
The interesting fact is that the Vardzia horizon is manily madeup of Volcanic tuff and these rocks can be cut even with a simple iron knife and this might be the reason of building the Vardzia complex into these rocks. There is a famous legend that this complex was being built at the highest mountain and some divine force kept bringing the tools to the Erusheti mountain. The legend goes that for three nights when the workmen finished their work and left the tools at the construction site, they found their tools at the Erusheti mountain. The fortress was built here as a command of the divine forces.
We climbed the cave complex and reached the highest point. It was an adventure worth taking. The beautifully built structure, the carving at the church, the wine cellars, the water spring and the secret passages from one level to different levels make this fortress a marvel of the ancient times.