if a comprehensive survey is completed. Dr. Tim Clarey has recently published an excellent article analyzing the Chicxulub site (Clarey, 2017). Dr. Clarey notes that reports of planar deformation features (PDFs) have been found in “samples from the Toba volcanic caldera, Indonesia”, citing Alexopoulos, Grieve and Robertson (Alexopoulos et. al., 1988). Clarey, citing another paper by Huffman and Reimold (Huffman & Reimold, 1996), states that they “described several conditions where the development of over-pressured conditions in the magmatic systems were sufficient to create PDFs, including quench supersaturation, catastrophic phase changes and gas-phase explosion. Under the right conditions and the presence of explosive gases, catastrophic gas reactions can contribute to a propagating, shock-induced wave front. Most of the shock-generating conditions described by Huffman and Reimold involve rapid ascent and rapid crystallization of magmas, which seem to be much more common than petrologists once believed”. The volcanic explosion of Mount Tavurvur in 2014, caught on video, seems to be another example of this kind of shockwave inducing explosion. So it seems that any feature that can be produced in either an impact or a terrestrial volcanic explosion cannot be considered to be an impact signature in a way that rules out volcanism. Another feature of some craters that has been put forward as explicable only with the impact hypothesis is the system of rays found along some craters. It is believed that they are the result of ejecta being explosively launched in all directions around an impact. However, underground nuclear explosions like Sedan have also produced ejecta blankets similar to both volcanic explosion craters like Mt. St. Helens and also some alleged impact craters like Barringer Crater. Indeed, in the video of the Sedan nuclear test, there are large chunks of debris leaving trails of dust through the air. On Earth, these chunks and clouds of debris encounter significant gravity and air resistance which prevent them from forming ray structures as large as those seen on the moon. So one way to test this hypothesis would be to bury a nuclear explosive on the moon and see what sort of crater and ray system it produces. This paper’s hypothesis predicts that it would for a crater pattern similar to those seen in other well preserved lunar craters. It has also been argued that steam explosions and meteorite impacts will operate in different temperature ranges. However, since equivalent amounts of energy are needed to produce equivalently sized craters, it is not clear why that should be the case. Furthermore, since (as argued above) impact explosions and volcanic explosions produce similar geological features, this is prima facie evidence that they also operate in similar conditions including similar temperature ranges. It seems that more work needs to be done modeling the conditions at the heart of a steam explosion now that we have computers capable of such simulations, but based on observed effects, it seems likely that such work would reveal some very high velocity impacts and also high temperatures caused by the explosion energy. Furthermore, there are some features on Earth that appear to have been caused by an impact or other high energy explosion, but that lack almost all of these alleged impact signatures. One notable example is the Hudson Bay Arc, also known as the Nastapoka Arc, shown below (Figure 9). Clearly the Hudson Bay Arc forms nearly half of an almost perfect circle. Despite several attempts to find impact signatures associated with this land form, none have ever been found. Features like this one place proponents of the impact theory on the horns of a dilemma. Either this is an impact crater, but the alleged impact signatures are not present, meaning that they are not impact signatures at all, or this is a crater formed by a volcanic explosion so massive that it caused a crater over 450 km in diameter, in which case even the largest of the lunar craters could also be the result of volcanic explosions. Neither scenario bodes well for the impact hypothesis. Are there any unambiguous signatures of impacts after all? 3. Barringer Crater Re-examined Since Barringer Crater, also known as Meteor Crater, figures so prominently in the history of the development of the impact model, it is worth taking another look at the evidence that has been put forward that it is in impact crater and not a volcanic maar crater. If the evidence for an impact formation of Barringer is equivocal, then the entire case for the impact origin of craters throughout the solar system can be called into question. A survey of craters throughout North America has been undertaken, and many craters have been found that share very similar morphological characteristics with Barringer, despite arguments to the contrary. In size, shape, depth, and proximity to volcanic rocks exposed at the surface, Barringer fits in exceptionally well with a multitude of maar craters found throughout North America, as well as around the world. As you can see, there is nothing immediate that stands out visually or topographically to make Barringer Crater obviously an impact crater whereas the others are undisputedly steam explosion craters, to which the label “maar” applies. Indeed, there are strong similarities. The diameter, depth, steepness of the sides, flatness of the bottom, and proximity to obvious volcanoes at the surface for Barringer are all in line with what we see for maar craters throughout North America. Furthermore, maar craters generally need both groundwater and Figure 9. Nastapoka Arc in Hudson Bay STERNBERG Craters and cracks 2023 ICC 18
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