Visions of the past in Mongolia
Survey and excavation in a remote region of Mongolia are revealing a wealth of information about an extraordinary concentration of rock art. Richard Kortum reveals what has been found, and why it is so significant.
Prehistoric petroglyphs are found in each of Mongolia’s 21 provinces. The largest and most important sites are in westernmost Bayan Ulgii aimag, long hidden in remote High Altai valleys carved by Pleistocene glaciers. On a reconnaissance mission in June 2004, a local Kazakh-Mongolian guide showed me a decorated boulder that I soon discovered was but a tiny fragment of what has turned out to be one of the richest and most concentrated assemblages of petroglyphs and ritual stone structures in Inner Asia. I have led field research here virtually every summer since.
The decorated boulder forms part of the Biluut Petroglyph Complex, which lies in the aimag’s north-western corner and is one of five or six significant complexes (that is, areas of substantial rock art with associated stone monuments) in this region. Situated on the eastern verges of freshwater Khoton Lake in Altai Tavan Bogd National Park, even for Mongolia this is the back of beyond. The park, created in 1996, contains some of the country’s most-breathtaking scenery and is home to abundant wildlife, including argali sheep and the elusive snow leopard, both immortalised by petroglyph-makers. On the lake’s south-western side, across from our annual field camp, the Altai ridgeline forms a border with China’s ALL Xinjiang Province. The permanently snow-blanketed Ondor Khairkhan Uul (High Holy Mountain), elevation 3,914m, dominates the scene.
Our study area measures nearly 28.5km²: 3.92km north–south by 7.25km east–west. Rising above the glacial plain are the twin Biluut high hills (referred to as B1 and B2 when identifying rock-art locations) and Juniper Mountain (aka Biluut 3, or simply B3), elevation 2,283m. Their glacier-polished bedrock panels of metagreywacke, a dense siltstone, contain 95% of the complex’s petroglyphs. The remainder are found scattered along the bottom of Broken Mountain, immediately east of B3; on Spring House Bluffs, a nearby ‘stack’ of exposed bedrock above a herder’s seasonal hut; and on three outcrops above where the meandering Khuiten stream empties into Khoton Lake.
Set in stone
Evidence suggests more-or-less continuous human activity here since the latest episode of glacial retreat, c.17,000 BC. With respect to cultural periods, Biluut petroglyphs run the gamut. Thousands are lost forever due to weathering, goat and horse hooves, and graffiti; still, outstanding specimens are preserved from the Stone Age through to modern times. Together with their pictorial details, the chronological distribution and spatial organisation of pecked images and associated ritual monuments cast a unique light on early communities and the palaeoenvironment with which they were intertwined. They track a changing climate and the routes of ancient people throughout South Siberia and Central Asia.
Ya. Tserendagva of the Mongolian Academy of Sciences, our chief field assistant Jagaa Bataar, and I have attempted to identify every petroglyph, no matter how obscure, within this area. Over several seasons, we have documented 12,000 individual figures and non-figurative, clustered ‘marks’, recording more than 20 data-points for each. Of Biluut’s identifiable figures for which a relative chronology can confidently be assigned, our current tabulation is 73.5% Bronze Age, 23.3% Iron Age, 1.4% Turkic (550-750 AD), and 1.8% ‘Archaic’– meaning pre-Bronze Age.
Our experiments in 2015 and 2017 with Varnish Microlamination (VML) analysis are refining the dating of Biluut petroglyphs. This technique was pioneered by geomorphologist Tanzhuo Liu of New York’s Columbia University and relies on manganese-rich and manganese-poor microscopic layers in the desert varnish that have built up in petroglyph grooves. As the former occur during wet spells, and the latter in dry periods, correlating them with the hemisphere’s scientifically dated climatic shifts yields minimum age limits with enormously greater precision – and has led to a few surprises. Liu’s analyses assign Biluut’s oldest surviving figures to the Upper Palaeolithic, ≥16,000 BC – thousands of years older than we originally believed. Stone tools found on site are estimated to be 12,000-15,000 years old. Some petroglyphs that we tentatively recorded as early Bronze Age now look to be Neolithic instead, ranging from 5,000 to 10,000 years old. Although neither period is yet recognised for Mongolian petroglyphs, VML dating might enable us to identify both Mesolithic and medieval figures (1200- 1500 AD). Excavated human remains from the medieval period on B2 suggest that the latter might be present.
Another surprise is the way figure-types and chronologies are distributed across the landscape. Against our initial assumption, petroglyph-makers here were not mere opportunists when it came to selecting spots for their creations. Instead, our data reveal interesting statistical correlations. So, for instance, the proportion of ibex, by far the most numerous of all figure-types, is far greater on B3 as compared to B2; the opposite is true of anthropomorphic figures. Archaic petroglyph-makers strongly favoured Khuiten Gol Delta, whereas Bronze Age artists evince a predilection for Broken Mountain, Spring House Bluffs, B1, and B3 (in that order). Iron Age image-makers overwhelmingly chose B2; those of the Turkic period favoured B2 and B1, completely ignoring panels at Spring House Bluffs, Khuiten Gol Delta, and Broken Mountain.
The overwhelming preference for B1 when depicting wheeled vehicles is no doubt a highly significant feature of this complex and requires explanation. After all, 26 of the 30 such images are located here, with 17 of these engraved on the middle terrace, known as B1C. Two are on B2; only one is found on B3. Ancient attitudes that connect landscape with mortuary and other symbolic, ritual, and ceremonial traditions, particularly among regional Bronze Age groups, hold the key to this clustering. Likewise, elevation, slope, nearest neighbouring imagery, clustering of image-types, solar exposure, and proximity to stone monuments are relevant to figure-placement. What these intriguing patterns say about the mindset and lifeways of the people who made these marks remains unclear.
A ceremonial centre
What began with an exploratory crew of two researchers and two assistants has grown into a long-term multinational, multidisciplinary project. My 2007 team conducted a detailed study of Biluut’s geology – ‘the rock of rock art’ – while carrying out an ultra-detailed laser mapping of B2 petroglyphs. In the summer of 2011, supported by a National Endowment for the Humanities ThreeYear Collaborative Research Grant, 40 individuals worked together at Biluut; at season’s end, we discovered the delta petroglyphs. In 2012, we numbered more than 50. During those two summers, our dirt archaeologists excavated 40 diverse sites: Neolithic, Bronze and Iron Age, Turkic, and medieval. Since 2014, with smaller teams of specialists I have focused on scientific dating (VML plus pollen analyses), photogrammetry, geomorphology, palaeoecology, and ritual or ‘sacred’ landscape.
This is an extract of an article featured in issue 106 of Current World Archaeology. Click here for more information about subscribing to the magazine.