Prehistory Decoded

Jim Powell, Emeritus Professor of Geology, has created another  new website  dedicated to informing the public about the Younger Dryas Impact Hypothesis (YDIH). Sites like Wikipedia, which feed into AI models like ChatGPT and Grok, cannot be trusted to accurately reflect the science. This time, Jim calls out the poor rhetoric, or pseudoskepticism, of some of the most prominent critics of the YDIH.

Three people were involved in the discovery of the lunar-solar calendar at Gobekli Tepe. Dr John Gordon, myself, and Claire Murdoch. John, a psychiatrist at the Turning Winds institute in Montana, USA, emailed me about how the top row of v-symbols on Pillar 43, shown above, likely represents a lunar cycle. I immediately saw that he was probably correct, as I had already read about a similar lunar tally-count in Alexander Marshack's work from the 1970s. However, I disagreed with his interpretation of the remainder of the calendar symbols. I soon worked out that the 11 little boxes likely meant "repeat the above count" and the 10 v-symbols in the bottom row were extra (epagomenal) days. Together, these symbols sum to 364 days. I was sure this had to be the correct interpretation, although I struggled to find a convincing way to complete the solar calendar count of 365 days. Surely, there had to be another v-symbol in the count? I described this interpretation to Claire Murd...

Holliday et al. (2023): Systematic Misrepresentations of Younger Dryas Impact Evidence Undermine the Reliability of their Critique – ScienceOpen Holliday et al. (2023) present a “comprehensive refutation” of the Younger Dryas Impact Hypothesis (YDIH), but in doing so make numerous incorrect or misleading statements about the studies they critique. Collectively, these mischaracterizations distort the scientific record and compromise the reliability of the reviewers’ assessment. In multiple cases, their review omits key caveats, exaggerates alleged weaknesses, or presents prior YDIH studies out of context, giving readers an inaccurate impression of the claims, methods, and evidentiary strength of the original work. For clarity and brevity, we examine representative examples drawn from six influential YDIH publications discussed by Holliday et al.: Firestone et al. (2007), LeCompte et al. (2012), Kennett et al. (2015), Moore et al. (2017), Wolbach et al. (2018), and Moore et al. (2019), a...

Jim Powell, Emeritus Professor of Geology, has created a new website dedicated to informing the public about the Younger Dryas Impact Hypothesis. Sites like Wikipedia, which feed into AI models like ChatGPT and Grok, cannot be trusted to accurately reflect the science. This is the actual scientific situation. The comet research group and other research groups have amassed a huge body of data across multiple impact proxies at over 60 Younger Dryas boundary sites. The overwhelmingly best explanation for this preponderance of reproducable data is that a major cosmic impact occured around 10,875 BCE that could have dramatically affected the environemnt, climate, people and megafauna across several continents. Given the range of sites found so far, the YD boundary layer, logically, must occur across a wide area - so the 60 sites found so far must sample only a tiny fraction of the YDB layer that actually exists. Critics, like Holliday et al., apparently prefer a different explanation for t...

The following paper will be submitted to the meeting, "Second MULTIDISCIPLINARY STUDY DAYS geo-archaeological on Mediterranean megalithism" (Palermo, Sicily, November, 2025). See the video on Youtube   for the actual presentation at the conference Early Developments in Astronomy, Arithmetic and Proto-Writing at Göbekli Tepe Martin B. Sweatman School of Engineering, University of Edinburgh, Edinburgh, Scotland, UK. Abstract Göbekli Tepe, a megalithic site in southern Anatolia, consists of many sub-circular enclosures formed by megalithic T-shaped pillars and a large number of other rectangular buildings. The pillars of this very early settlement, some standing over 5 m tall, are adorned with a complex system of symbols, including animal symbols and other geometric symbols. It is believed to date to ~ 9,500 BCE, although an older origin date within the Epi-palaeolithic period is likely. Recent analyses of Göbekli Tepe’s iconography suggest that its builders possessed conceptual...

Recently, Mark Boslough (who else?) wrote yet another scathing piece about the Comet Research Group and the Younger Dryas Impact Hypothesis (YDIH) in the Skeptical Enquirer (he's a long time member of their college).  The Problem with Inadequately Reviewed Fringe Science | Skeptical Inquirer In it, he holds himself judge and jury for an entire field of science; namely extraterrestrial impacts. Indeed, he infers the YDIH is is worse than pseudoscience; he regards it as a massive fraud, similar to Piltdown Man x 100. But the YDIH is actually a complex scientific debate that has raged for nearly 20 years and has pushed the boundaries of the science of airburst impacts. Ironically, (given the volume's title - see above), Boslough doesn't address any of these emerging scientific issues. Instead, he tackles the people involved. As aleady pointed out by James Powell in his "Premature Rejection" and "Pillars of Salt" articles, Peer review and the pillar of salt:...

Read all about this at the Cosmic Tusk It might be easier to document where the YD black mat isn't?

In a new paper, Fitzenreiter et al. (2025) may have just located the first known surface impact feature of the Younger Dryas impact. It's near Perkins, Louisiana. The feature is a surface depression which fills with water on a seasonal basis, i.e. a seasonal lake. Clearly, it's not a crater. But that's ok, as the Younger Dryas impact hypothesis suggests the event was caused by a multitude of comet fragments and not necessarily by a single large and dense impactor. So the YDIH doesn't need craters, although there may well be some associated with it. The surface feature is not very large. It's suggested to have been caused by a low altitude airburst, or touch-down airburst, that provided sufficient heat and force to scar the landscape below without forming a traditional crater. Such events are thought to be more common than crater-forming impacts, but evidence for them is harder to find (due to the lack of an obvious crater). While the paper details copious geochemic...

Origin of some of the ancient Greek constellations via analysis of Pillar 43 at Göbekli Tepe  Martin B. Sweatman and Dimitrios Gerogiorgis School of Engineering, The University of Edinburgh, The King's Buildings, Sanderson Building, Mayfield Road, Edinburgh EH9 3JL, United Kingdom. email: martin.sweatman@ed.ac.uk   key words: Greek constellations, Göbekli Tepe, Pillar 43   ABSTRACT We re-evaluate an astronomical interpretation of Pillar 43 at Göbekli Tepe in southern Turkey. Our analysis supports earlier conclusions that at least some of the animal symbols on this pillar almost certainly represent constellations related to those of the ancient Greeks. Presumably, the Greeks, Mesopotamians and other Neolithic, Bronze and Iron-age cultures towards the eastern end of the Mediterranean region were influenced in their choice of constellations and symbols by this pre-existing knowledge.   1.       Introduction This work investig...