Saturday, September 28, 2019


The Hogback, Las Animas
County, Colorado.
Photograph Peter Faris, 1997.

Lightning strike on the Hogback,
Las Animas County, Colorado.
Photograph Peter Faris, 1997.

Rock art on the Hogback,
Las Animas County, Colorado.
Photograph Peter Faris, 1997.

Vision quest enclosure
on the Hogback, Las Animas
County, Colorado.
Photograph Peter Faris, 1997.

Back in 1997 I had the opportunity to visit parts of the Pinon Canyon Maneuver Site, in Las Animas County, Colorado, on a field trip guided by Larry Loendorf, to view rock art that he and his team had recorded. Some of the sites are along a basalt dike known as “The Hogback”. Loendorf pointed out some locations along the Hogback bearing traces of lightning strikes as well as rock art and vision-quest beds. This “Hogback” is a basalt dike associated with the dike network that originated with the nearby Spanish Peaks. We all speculated that the lightning strikes on the “Hogback” might have made it special for local Native Americans and influenced its use for vision-quests as well as the placement of the rock art. Many of the images on "The Hogback" are of bison. Could it just be a coincidence that the thunder associated with the lightning strikes sounds like a herd of stampeding bison? Probably.

Rock art on a boulder with a
possible lightning strike, Three
Rivers, Otero County, New
Mexico. Photograph Jack and
Esther Faris, 1988.

Rock art on a boulder with a
possible lightning strike, Three
Rivers, Otero County, New
Mexico. Photograph Peter, 1998.

Rock art on a boulder with a
possible lightning strike, Three
Rivers, Otero County, New
Mexico. Photograph Jack and
Esther Faris, 1988.

Then in 1998 I took a trip to the Three Rivers petroglyph site in New Mexico, where the rock art is also found on the remains of a basalt dike. Looking back at my pictures from that visit I found a number of possible lightning strikes on boulders that contain rock art. Given these instances it would seem reasonable to look for evidence of lightning strikes when looking at rock art on basalt or other magmatic rocks. There might be some relationship between rock art and lightning strikes.

Well, it turns out there is a vague connection. It comes in the form of giant, carved heads and figures in Central America known as “Fat Boys”.

"Fat Boy", Guatemala,,
Public Domain.

“The ‘fat boys’ are sculptures usually associated with Olmec/Maya/Izapan sites in southern Mexico and Guatemala, especially near the Pacific coast. They look very different from the sophisticated sculptures we usually associate with the ancient cities of that area. They’re stumpy stone figures of very fat humans, with a big ball for the bottom and a smaller, flattened bell for the top. The arms can barely stretch across the wide belly.

Kaminaljuyu, - now mostly absorbed by Guatemala City, had the greatest number of ‘fat boy’ sculptures discovered at a single site. Some of the fat boy sculptures are so worn, they look like blobs, with no indication of features. Yet hundreds of large and small versions of the ‘fat boys,’ as the sculptures became known after their discovery, have been found across the Isthmus of Tehuantepec in southern Mexico, through modern Guatemala, and down into Honduras, Belize, and El Salvador.

"Fat Boy", La Democracia,
Escuintla, Guatemala., Public Domain.

Some of the sculptures, also called ‘potbellies,’ featured a collar around the figure’s neck, possibly a sign of wealth. Many were situated on pedestals. Some had a prominent navel. None had specific genitals that would identify it as male or female, though a few had a bulge at the bottom.” (Rollins 2018)

In January 1975, Vincent Malmstrom from the Department of Geography, Dartmouth College, Hanover, New Hampshire was conducting studies at Izapa, in the Pacific coastal plain of southeastern Chiapas State, Mexico. He found a large basalt carving of the head of a turtle. “When a Brunton compass was brought near the turtlehead a sharp deflection of the needle was observed, of more than 60°. No matter where the compass was moved along the perimeter of the sculpture, the needle continuously pointed to the snout of the turtle. Discovery of this magnetic field prompted the testing of all other exposed rock at the site for magnetic properties, but no others were detected. This would suggest that the Izapans knew about magnetism in that they had reserved a basaltic boulder rich in iron for their carving of the turtlehead, and had executed it so carefully that the magnetic lines of force all came to a focus in the snout of the turtle.” (Malmstrom  1976)

Then, in 1979, an expedition led by Malmstrom found that some of the carved basalt statues at Monte Alto, Guatemala, also had magnetic properties. “Vincent Malmstrom and his assistant, Paul Dunn, discovered that when a compass was held up to one of the “potbellies” at Monte Alto, the needle reacted. It swung away from true north and pointed at the stone. When they tested other potbellies and giant heads on the site, they found the needle was sharply attracted when they held the compass to the navel of some statues and to the right temple in others.” (Rollins 2018)

"Fat Boy", Wikipedia,
Public Domain.

Now there is the connection between these Mesoamerican sculptures and the rock art at “the Hogback” here in Colorado and at Three Rivers in New Mexico - lightning. They theorize that the magnetism in these basalt sculptures had been caused by lightning strikes.

“The intense currents of lightning discharge create a fleeting but very strong magnetic field. Where lightning current passes through rock, soil, or metal these materials can become permanently magnetized. This effect is known as lightning-induced remnant magnetism, or LIRM.” (Magnetism/Wikipedia)

Lacking a Brunton compass the Mesoamerican cultures would have determined the magnetic attraction of the boulders that they wished to sculpt with a piece of magnetite, naturally magnetic iron ore. It is believed that the magnetism made the boulders more attractive for the creation of sculptures because they could then show that the sculptures had a mysterious effect on an outside object.

The Olmec and related peoples of Mesoamerica actually knew of magnetism and may well have utilized it. “There is evidence that the Olmecs used lodestone, a naturally magnetic material, as a compass for navigation.” (Peat 2002:185) A shaped bar of lodestone, grooved for possible suspension, was found at one excavation. And if they knew about it, what about other New World cultures and groups?

So, should we check the dike at “Three Rivers” and at “The Hogback” for lightning induced remnant magnetism, especially at sites where rock art is located? Should this be part of the process at any rock art site on basalt or related magmatic rocks? Will a magnetometer become required equipment to study rock art? Would we be able to prove that there was a connection between the lightning induced magnetism and the rock art anyway?

NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.


Magnetism, https://en/

Paul A. Dunn and Vincent H. Malmström,
1979 Pre-Columbian Magnetic Sculptures in Western Guatemala, Dartmouth College, Hanover, New Hampshire 03755,

Malmstrom, Vincent H.,
1976 Knowledge of Magnetism in pre-Columbian Mesoamerica, February 5, 1976, Nature, Vol. 259, No. 5542, pp. 390-391.

Peat, F. David
2002 Blackfoot Physics: A Journey Into the Native American Universe, Phanes Press, Grand Rapids, MI.

Rollins, Kathleen Flanagan
2018 “Fat Boys,” Magnetism, and Magic, January 15, 2018,

Saturday, September 21, 2019


Neolithic stone balls,
Ashmolean Museum,
Internet, Public Domain.

Carved Stone Ball from
the British Museum,
Public Domain.

Here is one of my favorite conundrums involving rock art. These Neolithic carved stone balls – what the hell are they? “Carved stone balls are petrospheres dated from the late Neolithic to possibly as late as the Iron Age mainly found in Scotland, but also elsewhere in Britain and Ireland. They are usually round and rarely oval, and of fairly uniform size at around 2.75 inches or 7 cm across, with 3 to 160 protruding knobs on the surface. They range from having no ornamentation (apart from the knobs) to extensive and highly varied engraved patterns.” (Wikipedia) Originally thought to be associated with the Picts, these are now known to date from the Neolithic to Iron Ages, and thus predate the Picts who arose in the Late Iron Age.

Alford ball, Wikipedia,
Public Domain.

Towie Ball, from Scotland,
Internet photo,
Public Domain.

Towie Ball, from Scotland.
Wikipedia drawing,
Public Domain.

Suggested uses range from weapons (like mace heads, bolas, or sling stones) to tools (grinders like pestles, rollers like ball bearings for the stone blocks used to build Stonehenge, weights for fishing nets), standardized weights for traders, and of course the fall back for when you don’t really know anything, “objects of ritual significance or social status.” They have also been explained as perhaps functioning like the “speaker’s staff” to control or order deliberation in meetings. 

I would like to suggest another possibility related to the concept of social status. How about tokens of wealth like the “coppers” of the Indians of the Northwest coast of North America, or Rai (the stone money of the island of Yap). Tokens of wealth depend for their value on rarity. Rarity, in turn, depends upon how hard it is to procure the object in question because of either scarcity of the raw material or because of difficulty of fabrication.

North American Northwest
Coast Indian copper,
picture from Internet,
Public Domain.

In the case of the coppers prehistorically the material was very rare and hard to procure prehistorically for the native people, as well as the effort to produce the item was great. “Coppers, which are still in use today, experienced a real golden age in the 19th and the beginning of the 20th century. Due to contacts with western explorers and merchants their production increased substantially. However there are several indications that suggest they were already in use before the first contacts with the West, about 1790. The coppers were an exceptionally important symbol in the northwestern societies of the American continent. Apart from being a means of payment in a complex system of transactions, they were also a symbol of wealth and prestige.” (

Rai, stone money from the
island of Yap. Picture,
Public Domain.

And in the case of the Rai the production of the pieces involved a difficult process of stone carving as well as a sea voyage to and from the quarry on a different island. “Rai, or stone money (Yapese: ray), are more than 6,000 large, circular stone disks carved out of limestone formed from aragonite and calcite crystals. Rai stones were quarried on several of the Micronesian islands, mainly Palau, but briefly on Guam as well, and transported to Yap for use as money.” (Wikipedia) There is no limestone naturally on the island of Yap – thus scarcity. And, of course, prehistorically they had no metal tools so it took considerable effort to create them. When metal tools were introduced after contact Rai became much easier to create and this caused economic inflation and depreciation in the value of the Rai, but they are still held to be important by the people.

Glasgow Ball, Scotland.
Public Domain.

Stone Ball, Photo,
Public Domain.

Stone Ball, Internet
photo. Public Domain.

The value of these stone balls does not depend on scarcity of material, hard rocks are abundant in their homeland. It therefore depends on the difficulty of crafting them. It undoubtedly took considerable effort and precision to create most of these stone balls. “Many are said to be made of “greenstone”, but this is a general term for all varieties of dark, greenish igneous rocks, including diorites, serpentinite, and altered basalts. Forty-three are sandstone, including Old Red Sandstone, 26 greenstone and 12 quartzite. Nine were serpentinite and these had been carved. Some were made of gabbro, a difficult material to carve. Round and oval natural shaped sandstones are sometimes found. Examples made from Hornblende gneiss and granitic gneiss were noted, both very difficult stone to work. Granitic rocks were also used and the famous Towie example may be serpentinised picrite. The highly ornamented examples were mainly made of sandstone or serpentine.” (Wikipedia)

Elgin petrosphere, slate ball.
Internet photo, Public Domain.

“By the late 1970s a total of 387 had been recorded. Of these, by far the greatest concentration (169) was found in Aberdeenshire. By 1983 the number had risen to 411 and by 2015 over 425 balls had been recorded. A collection of over 30 carved balls from Scotland, Ireland and northern England are held by the British Museum.” (Wikipedia)

Some of these are fairly crude but many of them are examples of great precision and craftsmanship in their manufacture. I love the mystery here. Along with objects of considerable rarity, some of them are of beautiful design and execution, and no-one knows what they were for. We might as well call them dragon eggs. But they are rock, and artistic – thus, Rock Art.

NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.

REFERENCES: -america.htm

Metcalfe, Tom
2018 Enigmatic Stone Balls from 5,000 Years Ago Continue to Baffle Archaeologists, June 18, 2018, Live Science,

Saturday, September 14, 2019



Front cover.

I have received another volume of rock art in the series published by the Oregon Archaeological Society; Visions for Life and Death: Pictographs of the Lower Columbia River, by Keyser, James D., David A. Kaiser, and David L. Minick, 2019, Oregon Archaeological Society Publication #26, Portland, Oregon. ( I have personal ties (family history) to the region, and have spent considerable time there, so I was pleased to be able to delve deeper into the rock art and customs of the aboriginal inhabitants of that (the Dalles/Deschutes) area. The bulk of the rock art there is found to be either Central Columbia Plateau Style, or Yakima Polychrome Style. I have some little familiarity with these as, back in August 1983, I had visited a large Yakima Polychrome style site on a cliff by the river at Yakima, Washington, and, in July 2000, I had the opportunity to spend a day with Jim Keyser examining rock art in this (the Dalles/Deschutes) area, including some of the Spedis Creek panels (I have had a few other opportunities to visit rock art around the Dalles as well). This is some of my favorite rock art and I am very happy to have this detailed book about it.
Map of the study area.
Fig. 2, p. 3.

"Painted at two sites in the lower Columbia River region are fascinating sets of pictographs detailing the ritual activities of the people who have lived along the Columbia and Deschutes rivers for thousands of years. Bright red and red-and-white polychrome pictographs found at Spedis Creek and Harris Canyon document the vision quests of shamans and laypersons and show the deeply held beliefs people had about the Supernatural world. Informed by ethnography and mythology, these paintings are a testament to generations of people practicing their customs and passing their traditions and knowledge on to others. 
With dozens of photographs and color plates, accompanied by other illustrations, as well as various maps and charts, the authors present the first detailed study of a Yakima Polychrome type site. In addition, they undertake a detailed comparison between that site and a much simpler group of pictographs at the nearby Harris Canyon site."  
This publisher's statement from the back cover of the book only begins to describe this volume. 

Columbia River canyon
in study area,
Fig. 3, p. 4.

With a wealth of photographs as well as comparative tables and charts, the imagery from this study area is integrated with rock art of the greater region. It should be noted that this is also the area that houses the great Tsagaglalal, "She Who Watches", but that is slightly outside the study area covered by this volume.

Black and white recording,
Fig. 5, p. 12.

As important as the results of such a comprehensive study are, there is another important aspect of this, the process itself. Because they were not allowed to do mylar tracings (by the Washington State Parks Department) the black and white images which look like marvelously detailed field drawings are actually photographs processed with D-stretch, Photoshopped, and then printed in black and white. "During the Spedis Creek/Harris Canyon project we made no direct tracings of the pictographs or petroglyphs at either site. Instead we based our recordings of the imagery entirely on color digital photography. This exclusive reliance on color photography results in some issues that must be discussed. The first is our production and use of what we term photo-tracings. There are two sorts of such images. The simplest is stipple tracing done directly from the photograph. This is much like a direct tracing of an image, but one cannot control for the parallax that occurs when the camera lens is not absolutely parallel to the painted or carved surface, or when the surface itself has irregularities.
Other photo-tracings are made using the "color-replacer" tool in the Paintshop Pro or Photoshop programs. This technical operation involves selecting the color of the parts of an image one wishes to save and removing all other color from the photograph.
Using photographs already manipulated by the DStretch enhancement often means that the image of the pictograph one wishes to preserve  is shown in the photograph as some combination of strange pink, white, orange, or even grey-black colors. Clearly making such a photo-tracing with the use of the color-replacer tool is a complex technical process that must be carefully orchestrated to eventually produce a two-color, black-and-white version of the image in the photograph." (pages 14-15) This will undoubtedly prove an important technique for many rock art recording projects in the future.

Spedis Creek panel,
enhanced with DStretch.
Plate 27.

One problem I have found in the past in recording rock art with team members who have artistic training is that they often cannot resist the urge to make small changes to improve it - "to make it look better."  That is changing the image, not recording it. In one recording project that I led a number of the field sketches by "artists" (self-identified, not academically trained) had to be discarded. Normally I would say that there is a danger in using such photo manipulation to produce the final record, that decisions might be made on the basis of creating an attractive result, not the most accurate one, but with this team, and knowing Jim Keyser, I am fully confident that the final record is as accurate as it can possibly be. 

All in all "Visions for Life and Death" is a marvelously detailed book by a highly professional team, of an area rich in important rock art. And, another important publication by the Oregon Archaeological Society. I am grateful to all of them for this contribution to the record of Northwestern rock art, and at an almost giveaway price.

The book is:

Keyser, James D., David A. Kaiser, and David L. Minick
2019 Visions for Life and Death: Pictographs of the Lower Columbia River, Oregon Archaeological Society Publication #26, Portland, Oregon. 
8.5″X11″ 112 pages, 59 illustrations, 6 pages of color photos
ISBN #: 978-0-9915200-4-6
OAS publication #26
Price $16.00 plus $4.00 Shipping and Handling.

Saturday, September 7, 2019

HERE THEY COME AGAIN: Decoding European Palaeolithic Art: Extremely Ancient Knowledge of Precession of the Equinoxes.

Pillar 43 at Gobekli Tepe, Turkey.
Photo from the Internet,
Public domain.

On December 1, 2018, I posted a column titled Astronomy in Rock Art – Decoding Gobekli Tepe? about wild speculation that carvings at Gobekli Tepe can be read, and encode the date of a comet strike on earth that caused the Younger Dryas. This claim was published by Martin B. Sweatman and Dimitrios Tsikritsis of the Engineering Department of the of Edinburgh in a paper titled Decoding Gobekli Tepe With Archaeoastronomy: What Does The Fox Say?, (see References below for complete citation). Now, Sweatman is back with even more sweeping and far-fetched claims. He and new partner Alistair Coombs have published Decoding European Palaeolithic Art: Extremely Ancient knowledge of Precession of the Equinoxes.

To try to prove their case statistically they go through a complicated chain of logic that states that their interpretation has only “around 1 in 100 million” chance of being wrong, or from their Appendix B, “Multiplying all these probabilities together gives a chance of 1 in 300 thousand that Göbekli Tepe does not implicate the Taurid meteor stream in the Younger Dryas impact event.” (Sweatman and Coombs 2019:12) Now I am not a statistician, and if I was really good at mathematics I would probably not be an art historian, but to me this is actually ridiculous. It depends on their having been correct in their suppositions in identifying 12 star constellations/asterisms with carved animals at Gobekli Tepe. I have said before that we do not even know if all of these ancient cultures identified constellations/asterisms in the sky, and if they did we cannot begin to guess what they saw. Yet, this whole construct is built on guessing that their 12 identifications are correct. This is one of those logic chains that starts with a whole bunch of maybes and then uses them to supposedly definitely prove something – you cannot do that.

In my December 1, 2018, column Astronomy in Rock Art – Decoding Gobekli Tepe? I presented Sweatman’s theory that the vulture pillar at Gobekli Tepe is a record of a comet that struck the earth and caused the Younger Dryas climate event (see Sweatman and Tsikritsis 2017). They matched images from the carvings on pillar 43 with constellations (all assumed on their part, there are no records proving any connection). They then used their relative positions to calculate a date which they presented as the date of the cosmic catastrophe.

Shaft scene at Lascaux cave,
France. Photo from the
Internet, Public domain.

Now, using the same logic(?), they have expanded their studies to Paleolithic Europe. “The final piece of the logic puzzle is provided by the famous Shaft Scene at Lascaux which has an almost identical interpretation to the Vulture Stone at Gobekli Tepe. They differ only in the date of the catastrophe memorialized and the recorded radiant of the cometary strike.” (Sweatman and Coombs 2019:6)

“Another clue to the meaning of the shaft scene is provided by the fact that only four different animal symbols are displayed here; a bison/aurochs, duck/goose, and rhinoceros (to the left of the falling/dying man) on the main wall with a horse on the rear wall. -  The horse on the back wall is not often described as being part of this scene, but it is central to the interpretation described next.

Similarities with Gobekli Tepe’s Vulture Stone are striking. Both display a man, possibly dead or dying and both display four prominent animal symbols. At Gobekli Tepe the four animals are the vulture/eagle, bear, ibex/gazelle and tall bending bird corresponding to the four solstices and equinoxes at the date of the Younger Dryas event. It is therefore sensible to enquire whether the Shaft Scene at Lascaux is equivalent to the Vulture Stone of Gobekli Tepe and can therefore be decoded using the same method.” (Sweatman and Coombs 2019:6)

“Noting the bison/aurochs and duck/goose symbols in the Shaft Scene, and using Table 1 and Stellarium we immediately find the following;

  • Bison/aurochs = Capricornus = summer solstice between 15,350 and 13,000 BC
  • Duck/goose = Libra = spring equinox between 15,700 and 14,100 BC
Therefore, this scene might represent a date anywhere between 15,350 and 14,100 BC. To narrow down this range we need to consider the other two animal symbols. Unfortunately, neither of these symbols has previously been decoded. But logically, they are unlikely to correspond to constellations that have already been decoded. When we consider this date range we see the following possibilities;

  • Autumn equinox: Taurus 15,350 to 14, 950 BC, or Aries 14,950 to 14,100 BC
  • Winter solstice: Leo 15,350 to 14,800  BC, or Cancer 14,800 to 14,100 BC
Given that in Tables 1 and 2, Aries is represented by the ram and Cancer is represented by a large feline, and that rams and felines are recorded in Palaeolithic art, it is likely the date range is limited to between 15,350 and 14,950 BC, and therefore the rhinoceros and horse likely represent Taurus and Leo. When we consider these constellations at sunset (see Table 3), which is the convention for this system (1), we find that the rhinoceros and horse are good fits to their respective constellations (Taurus and Leo), which provides further confidence in this interpretation. We therefore suggest that the Shaft Scene encodes the date 15,150 ± 200 BC, and we have now completed our ancient zodiac.” (Sweatman and Coombs 2019:6-7)

They have identified 12 constellations in this ancient zodiac. Perhaps a natural assumption considering that our zodiac has 12 constellations in it, we are pre-programmed to think that is the correct number (and please don’t come back to me with comments about how the phases of the moon in a lunar year determine the number and it’s rising month by month mark the constellations). But, we have no way of actually knowing what constellations the ancient Europeans who painted Lascaux, or the ancient Anatolians of Gobekli Tepe, thought they saw in the sky, let alone the number (if any) that they identified.

“Now that we have a date, we can try to interpret the scene. What should we make of the falling/dying man and the speared/dying bison. Given that the Vulture Stone at Gobekli Tepe very likely refers to the Younger Dryas event and, according to Napier and Clube’s theory of coherent catastrophism, this is unlikely to be an isolated incident, could the Shaft Scene represent another encounter with the Taurid meteor stream? At Gobekli Tepe, the fox featured on the largest central pillars of the largest enclosure yet uncovered, indicating the event dated by the Vulture Stone refers to a cosmic event from the direction of northern Aquarius. Instead, the Shaft Scene displays an injured aurochs, representing Capricornus, not a fox. Is the aurochs here equivalent to the fox at Gobekli Tepe? To answer this we need to consider the precession of the Taurid meteor stream.

As described earlier, the longitude of the ascending node of the Taurid meteor stream is expected to precess at the rate of one zodiacal sign every six thousand years. Today the Taurid meteor stream radiant is centered (and hence maximal) over Aries. Therefore, at the time of the Younger Dryas event, around 13 thousand years ago, it would have been certered over Aquarius, described at Gobekli Tepe in terms of the fox. On the date depicted by the Shaft Scene, around 17 thousand years ago, its center would have been over Capricornus. Therefore, the injured aurochs in the Shaft Scene is consistent with its interpretation as a Taurid meteor strike from the direction of Capricornus. Hence the injured or dying man might indicate a catastrophic encounter with the Taurids, as for the Vulture Stone of Gobekli Tepe.”  (Sweatman and Coombs 2019:7)

Remember, above I quoted their claim that their interpretation has only “around 1 in 100 million” chance of being wrong.” Looking at all of their suppositions and the maybes/mights/possibly/perhapses it took them to reach their conclusion, how realistic do you think this claim sounds now?

Here at RockArtBlog, I really do not like to write attacks on people’s beliefs. I would much rather act as a cheerleader for a wonderful new theory or project. But, since these authors have academic credentials they get away with this, and this kind of nonsense needs to be called out. Go back and read their papers for yourselves. I could not find a single conclusion of theirs that is actually based upon provable fact. My own calculation on this says that they have about a 1 in 50,000 chance of being correct, but like I said, I am not a mathematician. If they had only learned the use of the words “maybe” and “perhaps” I could accept their work as interesting speculation, but never as proven fact. I do, however, invite you to check and decide for yourself.

NOTE: Images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.


Faris, Peter
2018 Astronomy in Rock Art – Decoding Gobekli Tepe?, December 1, 2018,

Sweatman, Martin B., and Dimitrios Tsikritsis,
2017 Decoding Gobekli Tepe With Archaeoastronomy: What Does The Fox Say?, p. 233-50, Mediterranean Archaeology and Archaeometry (open access), Vol. 17, No. 1.

Sweatman, Martin B., and Alistair Coombs,
2019 Decoding European Palaeolithic Art: Extremely Ancient Knowledge of Precession of the Equinoxes, Athens Journal of History, Vol. 5, No. 1, pages 1-30.