[meteorite-list] Why isnt documenting meteorites stressed enough? (Diregard Previous Post)
From: Paul Heinrich <oxytropidoceras_at_meteoritecentral.com>
Date: Sat, 13 Mar 2010 20:36:20 -0600 Message-ID: <4B9C4BA4.4010705_at_cox.net> Please disregard my previous post as the bottom part of it was chopped off when I sent it Eric wrote: "Meteorite fragments found on dry lake beds or anywhere on "old ground", do in fact move. In my opinion coordinate data is still valuable, but not as valuable as say data from a fresh meteorite fall." As a geomorphologist, I would disagree. Such data from either "old ground" or "prehistoric falls" might be just as valuable as data from fresh falls. The distribution data from prehistoric falls, if collected and preserved might be useful in evaluating the type and rate of the geomorphic processes that modify and the age of the landforms on which they are found. This is because a meteorite strewn field in many ways is a chronostratigarphic equivalent of a volcanic ash beds in terms of providing a "deposit" that is of the same age / point in time everywhere that pieces of it are found. The way that individual meteorites belonging to a single strewn field are moved about could be used to infer how the surface of a landform has been modified and at what rate since the meteorite fall creating it occurred. If the strewn field data was collected and was accessible, I would suspect that geomorphologists would use that data in a wide variety of novel ways that neither I or nobody else on this list could at this time predict or image. Of course, once the "taphonomic" processes determining how meteorites are moved around after a fall and whether or not they are preserved are understood, I suspect that a person can "back engineer" the process to predict where to look for "fossil meteorites" from past falls even if they have been buried. I still think that there a number of Chinese falls, where even though they occurred centuries ago, a person has a significant chance of still being able to find meteorites from them if their "taphonomy" could be figured out and predictions made as to where exactly to look. Looking at some of the phrase diagrams that archaeologists have made showing the relationship between different physical characteristics of soils and sediments and the long term survival of iron artifacts, it is quite clear that iron objects, including meteorites, under specific circumstances can survive even in wet soils and sediments that they become buried in for significantly long periods of time. They might be bit too rusty for many collector's tastes. Still, they still have scientific value even in less than pristine condition. Just Some Thoughts, Paul H. Received on Sat 13 Mar 2010 09:36:20 PM PST |
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