How Did Göbekli Tepe’s Neolithic builders decorate their megaliths?
The discovery of Göbekli Tepe (GT) has largely settled this debate.
Southeastern Turkey’s Neolithic hunter-gatherers evidently had enough spare time and food to construct megalithic monuments.
Which puzzled GT’s first lead archeologist, Klaus Schmidt, as he thought the many hundreds of people involved in its construction would have quickly depleted community food supplies [1].
But could it be that Schmidt’s assumption of hundreds of workers is wrong?
Göbekli Tepe’s builders had evidently mastered the art of quarrying, transporting, decorating, and erecting limestone slabs of up to 15 tons. This technology was likely pioneered and perfected at older Taş Tepeler sites, such as Karahan Tepe (KT), whose megalithic slabs /pillars are mostly smaller and less ornate than GT’s.
I was shown around the KT site by one of its active archeologists. We stopped near a quarried but unused 3 meter long T-pillar (below) for a discussion on megalith technology.
Recent evidence indicates KT pre-dates GT by at least several centuries, which is more than enough time for Neolithic construction crews to have gained the expertise necessary to quarry, transport, erect and decorate the megalithic pillars of the impressive GT monuments.
My KT archeologist guide didn’t think any advanced technology was required. The quarried pillar (above) measures about 3 m* 0.5 m * 1 m = 1.5 m3. The density of limestone is about 2700 kg/m3, so the pictured slab weighs about 4 tons.
The pillar could therefore be carried by 20 men, assuming the Neolithic builders could each dead-lift 200 kg. But only half or less would be required if they pivoted the slab – or pushed the slab overgreased wooden rails – onto a gurney.
As far as moving the slab is concerned, my archeologist guide thought they probably rolled the slab on logs, and could easilytransport the slab from the quarry to KT (150 meters) in a few hours.
The museum in Şanlıurfa has dioramas (below) visualising this.
The method is plausible as the KT area was likely a wooded steppe after the Younger Dryas [2], so logs would be available. The previous sections demonstrate that megalith transport and erection
likely didn’t require any knowledge-transfer from a technologically-advanced society or excessive time and manpower resources: 10-20 men working for a few hours to a few days, possibly scaled-up for the larger slabs.
The quarrying and decorating however would seem to require much more resources, so any technology that could reduce this burden, or shift it to those not directly involved with hunting and gathering food, for example children, the elderly, the infirm, etc., would reduce Schmidt’s headcount.
The construction of GT pre-dates the oldest evidence of smelting of metals by several millennia. The Şanlıurfa museum therefore suggests – in a separate diorama (above, right) – that the quarrying used stone axes and wooden chisels, although this seems a rather onerous workout to someone who has spent hours trying to hack out a fossil using modern tools.
Whether by luck or design, the KT and GT builders selected sites where the obvious choice of building material is limestone, a rock type that is well-suited for Neolithic monument construction. First, it can be almost as durable as granite or basalt in the short term: Victorian curbs were often made from quarried limestone before concrete became popular.
Next, it is relatively light: it’s density (2700 kg/m3) is about the same as granite, but lower than basalt (3000 kg/m3), which reduces the weight of the pillars.
Lastly, it is relatively soft. With a Mohs hardness of 3, limestone is harder than gypsum (2) but considerably softer than granite or basalt (6-7), which means one can easily scratch out low-relief drawings using an antler, obsidian or a sharp piece of basalt.
Despite this softness, the quarrying of a 3 m limestone T-pillar is a daunting task, even using modern tools. Using Neolithic tools such as a stone axe and a wooden chisel the job would a) take forever and b) be a very messy affair.
Curiously, the decorated and unused pillars at KT and GT, and the rocks from which they were quarried, are often neat and show a complete absence of any tool marks.
Instead, the unused and broken pillars in the KT quarry often have man-made curved channels (above) at their edges that were obviously used to conduct fluids. Their location strongly indicates they were either used in, or are a by-product of, the quarrying process.
A similar channel is found near KT’s “Chamber of Phalluses” (below).
A close examination reveals that these channels were likely “etched” by acid rather than hacked by axes. Limestone is mainly made up of calcium carbonate (CaCO3), a mineral that readily dissolves in acids such as hydrochloric acid (HCl; used as a field test by geologists), citric acid (lemon juice) and acetic acid (vinegar).
This property was almost certainly known to the Neolithic community: even my ten-year old daughter accidentally discovered how to etch a lemon into our limestone kitchen counter while making lemonade.
The KT and GT builders would likely have had access to both lemons and vinegar: there’s strong evidence that they made wine and beer [1]. If salt was available, for example from north Iran
or from Çankırı, a salt cave in use for at least 5000 years, then hydrochloric acid could be made by combining the organic acids with the salt.
If this all seems – literally – far-fetched then it should be remembered that [5] “the style of some of the obsidian and stone tools [found at GT] suggest that people were coming [to GT] from Iraq, Iran, the Middle Euphrates and the eastern Mediterranean.”
Other pre-iron builders also likely used sulphuric acid from the bacterial / fire oxidation of pyrite (fools gold) as well as oxalic acid from plant sap, both of which can be even more acidic than hydrochloric acid [3]. Pyrite is commonly found near GT, for example in the Şehitkamil district [4], so it is very likely Neolithic humans would have noticed its corrosive weathering effects during their hunter-gatherering forays.
To test the feasibility of acid-quarrying technology I performed a small experiment on the limestone rocks just outside of Karahan Tepe. I poured about 10 g of salt and the juice from a single lemon on a small exposed limestone area that immediately began to fizz impressively, proving that limestone was being dissolved.
Upon returning an hour later, the limestone had eroded to a depth of about 5 mm (below; note rice grains for scale), and had started to etch a downslope channel.
Acid would have been poured along a channel (yellow arrow). In the relatively flat areas (A) the standing acid would have mainly eaten its way sideways and downwards, causing the severely corroded rockface (A).
In the steeper areas (B) the flowing acid would have etched a smoother rockface. Note the lack of any toolmarks. Also note the shallow, circular depression (blue arrow) which may represent early decoration works or the place where a sloppy worker placed their acid vessel.
Similarly, the high-relief decorations were likely etched using acid. Scratching low-relief zoomorphic decorations into GT’s pillars using an antler, obsidian or a sharp piece of basalt is relatively easy.
For example,Enclosure B’s western central pillar (pillar 9) has what appears to be a(fairly childlike) boar scratched into it. Such “scratched” decorations are much less impressive (or identifiable) than for example the same pillar’s high-relief, leaping fox.
These more impressive high-relief decorations however would have required days to months of grinding using primitive handtools, so it’s curious and noteworthy that these resource- intensive
high-relief pictograms seem to much commoner at GT. Etching these pictograms using acid would have been far less time-consuming and relatively easy: the high-relief pictogram would be covered with an acid-resistant material, for example clay, whereafter the surrounding limestone could be etched away.
GT Enclosure C’s main pillar (37, above left) shows large pits (vugs) on its discoloured, decorated side (as do most decorated pillars), but none on its fractured top, indicating the decorating process – etching – likely caused the discoloration and pitting, due to unstable components such as fossil shells dissolving much quicker than the more stable parts.
Pillar 24 (above right) was possibly still being decorated at the time of Enclosure C abandonment: the strongly corroded outer surface layer lower on the pillar was being removed via etching from the more slender top part, possibly to make it level with the enclosure wall.
Using acid in quarrying and decorating has numerous advantages:
It’s orders of magnitude easier to etch a high relief decoration than to grind it.It can be done by the physically weaker members of the community, for example the elderly, the infirm, or even small children, that is those not involved with food supply.
This in turn would mean thatmonument construction could continue for longer periods of time,and would require less resources (manpower, food)
The decoration of the pillars can happen after their emplacement (e.g. pillar 24), that is after the enclosure was being used for ceremonies.
The GT decorations are very impressive and beautiful, but rather child-like and coarse when compared to bas-relief figures carved using metal chisels, such as a Bronze Age Egyptian one at Saqqara (below), that are much finer yet often do show tool marks.
The absence of tool marks at GT can however also be explained by later weathering and erosion, or by the builders grinding them off using some form of Neolithic file or sand paper. The corrosion of limestone face A in the quarry next to the unused pillar is more severe than any other face in or near the quarry, but could have also been caused by later runoff erosion and weathering.
However, it’s highly peculiar that water erosion would cause both smooth (B) and severely corroded (A) faces in close proximity to one another. It’s also possible to use stone hand tools to quarry and grind even harder materials than limestones: the Incas reportedly employed large construction teams who used stone tools for cutting and grinding much harder rocks [3].
But what would be the point of hacking and smoothing curved channels in the quarry next to the T-pillars using axes? Any uncertainty on whether acid was used at KT and GT can be further reduced via a dedicated study, for example via an MSc.
Geology or Archeology project that looks at (acid) chemical traces on the pillar and quarry faces, and at the microscopic textures present in thequarry and pillar faces and along fractures.
A more entertaining version can be found on the Think and Hammer substack https://open.substack.com/pub/thinkandhammer
Please Donate Below To Support Our Ongoing Work To Defend The Scientific Method
PRINCIPIA SCIENTIFIC INTERNATIONAL, legally registered in the UK as a company 
incorporated for charitable purposes. Head Office: 27 Old Gloucester Street, London WC1N 3AX.
Trackback from your site.
aaron
| #
why is every ‘ancient’ structure a temple??
balderdash!
Reply
Andy Rowlands
| #
Calling sites temples is a common thing in archaeology when we don’t know what the sites were used for.
Reply