http://SaturnianCosmology.Org/ mirrored file For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== A Catastrophe of Comets The geophysical world according to me, and a few folks I happen to agree with Notes on ignimbrite emplacement, Part one One of the biggest problems I have been struggling with is the lack of adequate descriptive terminology. Much of the recent work on the YDB has shown chemistry that indicates a thermal explosive event of extraordinary power, and proportions. And most of the research papers speculated on the nature of the impactor as being ‘something different from anything studied before.’ Or words to that effect. So that , if we should find ourselves looking at that enigmatic something, we are on our own. And new descriptives must be made. Because, not only has it never been studied before, it has never been described. And, in fact, describing the event is especially problematic. Because it turned out to be vastly different from anything we ever even imagined before. When I first noticed the material movements of the Chihuahuan ignimbrites, the sudden, violent, motions of their emplacement were unmistakable. The view from very high altitude is a new perspective that Geologists of Generations past wouldn’t have had access to. But from 30, or 40 miles up we see an intricate, interflowing, region of very fast flowing melt that was moving, and splashing like a raging whitewater flood at the time of it’s emplacement. The first word to come to mind was ejecta. But that word didn’t work because no craters… Ejected from what? Most of the maps of the region label it as volcanic tuff. But we don’t see enough vents, or magma chambers, to account for even a fraction of the melt. The standard theory is that they originated in a so called ignimbrite ‘flair up’ during the mid tertiary. When vast rifts are thought to have opened up in the middle of the continent that spewed a few thousand cubic miles of ignimbrites and then closed again, without a trace. But the crazy mantle physics required for the giant, trap door, rift vents they propose just don’t work in the real world. And such a disappearing vent has never been observed. And then there is the fact that if we were to measure the total volume of material in the magma chamber beneath a super volcano such as the Yellowstone, or Toba, we would only have a tiny fraction of the volume of the Chihuahuan Ignimbrites. If we want to hold to the idea that they originated in a giant volcanic eruption we have to work from pure, untested, assumptions that don’t stand up to any scrutiny at all. If we want to accept the scenario that begins with, ‘Most Geologists agree that…’ We will need to assume that a still undiscovered magma chamber many hundreds of times bigger than Yellowstone, or Toba, exists beneath central Mexico. And we will need to account for how, after twenty five million years or so, those ignimbrites are still in pristine condition, at the surface, and at the pinnacle of the stratigraphic column, with almost no sign whatsoever of hydrologic decomposition from the forces of weather. After digging a little in the old literature to see what was known about them, as opposed to what was assumed, I came to the realization that, in fact, very little is known about them at all. Almost all of the geophysical research in the region is funded by mining companies prospecting for mineral resources. Basic geophysical research is something for universities to worry about I guess. But, as a result, except for about 100 kilometers, or so, along the Chihuahua City – El Paso highway, they are almost completely unmapped. And no one can provide a single map showing the location of one of those supposed rifts that can be reconciled with the patterns of movement, and flow, at the time of emplacement, which are clearly, and legibly visible in high altitude aerial images. To get a handle on how the standard theory of ignimbrite emplacement could get so screwed up, we need to take the old thinking apart a little. The old assumption is that only explosive volcanism produces ignimbrites./ (It should be noted that impact melt is often mistaken for ignimbrite)/ In a normal explosive eruption the materials are under extreme pressure until they get to the mouth of the vent. Upon being ejected from the vent, momentum takes over as the motive force and carries it; sometimes high up into the stratosphere. It then falls back to Earth as gravity takes over as the motive force, pulling it down-slope away from the volcanic vent. The result is an eruptive process that has been witnessed many times in living memory: A pyroclastic flow. After thundering down the slope, and coming to rest, the result is ignimbrite, literally translated as ‘Fire Cloud Rock’ So, under standard theory, pressure is only a motive force for ignimbrite flow while it is still magma in the ground. After that, we should expect that gravity, and momentum, are the only available motive forces. But without slopes to flow down, we can’t assume gravity as a motive force. And without magma chambers, and/or vents, we can’t make a case for volcanism as the source. The patterns of movement, and flow, are dramatically obvious in high resolution, high altitude, aerial photos. And a careful study of the fluid motions of the sheet ignimbrites of central Mexico quickly reveals, in exquisite detail, a thermal explosive process of simultaneous ablation, and emplacement, which is completely inconceivable from the strictly ground based observations, standard theory viewpoint of the past: The melt was pressure driven from behind like frothing whitewater waves on a stormy beach by atmospheric forces alone. And it did not come out of it’s source locations in an eruptive event. It was flash melted, and blown off of it’s source locations in an explosive event. And ‘Fire cloud rock’ is a bit of an understatement. But it’s still an excellent descriptive. Map1 /The southwest impact zone is indicated by the yellow oval. The post impact firestorm area is roughly defined as the area outlined in green. / Much of the literature assumes multiple eruptive events for the Chihuahuan ignimbrites. But again high altitude imagery shouts the truth. No matter what the source of heat, and pressure that melted, and moved them; whether volcanogenic, or the result of a thermal ablative airburst event, all ignimbrites are a fluid in motion at the time of their emplacement. And they solidify very quickly upon coming to rest. We can know that any given fragment of ignimbrite was only in a fluid state for a few violent seconds at most. so if two colliding flows are events separated in time then one of them will be seen to be overtopping the other. But we don’t see that in central Mexico. In the pristine sheet ignimbrites, random colliding, and interflowing from every direction, and covering more than 40,000 square miles of central Mexico, and west Texas there is not even one overtopping flow. Every interaction between colliding flows can be described as a fluid convergence, such as two rivers flowing into one. We can therefore state as empirical fact that it was all flowing at the very same time. So we see a more than 40,000 square mile mega flood of flash melted, fast moving ignimbrites. And an intricate, almost infinite, dance of random directional, interflowing motion. The ignimbrites describe motions. All of those motions describe the very same sudden moment. A gravity attracted fluid will always flow to the lowest elevation. The motive force is in front of it, pulling it down slope. But an unconfined fluid which is driven across a fairly level surface by a wind blowing over it from behind will behave differently. It moves from the area of highest pressure to the lowest. With distance from its pressure source, its motion slows, and it piles up at the areas of lowest pressure. In the case of ignimbrites born of a thermal ablative airburst event. Identifying the source locations for the materials is easy. You simply backtrack the flows to the bare places where there are no ignimbrites. At the source locations, the orogenies, and other blasted landforms, of the region have been assumed to be very ancient. Because they appear to be heavily eroded. The trouble with that standard assumption is a serious lack of alluvium covering the ignimbrites, which are in almost perfect condition, except for the occasional sagebrush, or cactus, growing in the cracks. But no one could have imagined that they are in fact heavily ablated by a thermal ablative process that produced, and emplaced the ignimbrites in seconds. Map2 Every square inch of the area within the oval is a blast effected material of an explosive event. Below is a small part of the main impact zone. A close study of the motions of the ignimbrites gives one an understanding of why I have called them a ‘Rosetta Stone’. The mountains, and orogenies among them have been described as heavily eroded. And the perceived amount of erosion is the basis for their estimated ancient age. The problem with that estimate is the almost complete lack of alluvial by products of hydrologic decomposition. If we want to say the ignimbrites were emplaced 25 million years ago. And that the landforms in this image have been eroding slowly for all the time since, then we are going to need to account for the missing alluvium. And we are going to give a plausible explanation of how the ignimbrites have survived unchanged for so long on the surface. DB2 These next three images are all found in the image above. The Lat, and Lon, are in the info bar. I hope you take a closer look for yourself with Google Earth. The image quality is as good as it gets. And you can zoom in and study even the tiniest details. DB4 All the way around the mountain above, the ignimbrites were blown away from it with all the speed of an ejecta curtain. But look closely along the left side about a quarter of the way in, and you can see where two of the fragments have detonated at ground level into the still moving melt. DB1 This mountain is non volcanic. Look closely, and you’ll see that it is composed of uplifted meta-sedimentary rock. Click Here to see Mark Boslough’s super computer simulation of a very large, high altitude thermal airburst. Note the post impact, upwards flow in the center of the down blast vortice, and you’ll see that this mountain, and its radial ignimbrite curtain is a perfect match for the simulation. We see that the mountain is the central uplift caused by just such an impact event. And the deep V shaped excavations that get wider at the top are a signature of the upwards flow at the center of the post impact vortice. Also note that its ignimbrite curtain was met on all sides by ignimbrites moving in all directions. It was all one multi fragment event. These ignimbrites are the geologically recent planetary scaring of a kind geologic process/impact event that has never been imagined before, much less described. But just to keep things simple I’ll describe it as a thermal-airburst-geo-ablative impact structure. It’s a pretty common land form. DB3 Published on March 18, 2010 at 3:46 pm Leave a Comment