Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/17/84; site bcsaic.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!vax135!cornell!uw-beaver!fluke!ssc-vax!bcsaic!pamp From: pamp@bcsaic.UUCP (pam pincha) Newsgroups: net.origins Subject: Re: archeopteryx: THE PILTDOWN CHICKEN Message-ID: <350@bcsaic.UUCP> Date: Mon, 28-Oct-85 12:57:37 EST Article-I.D.: bcsaic.350 Posted: Mon Oct 28 12:57:37 1985 Date-Received: Wed, 30-Oct-85 06:35:39 EST References: <420@imsvax.UUCP> <880@gitpyr.UUCP> <336@bcsaic.UUCP> <814@psivax.UUCP> Reply-To: pamp@bcsaic.UUCP (pam pincha) Organization: Boeing Computer Services AI Center, Seattle Lines: 58 Summary: In article <814@psivax.UUCP> friesen@psivax.UUCP (Stanley Friesen) writes: >In article <336@bcsaic.UUCP> pamp@bcsaic.UUCP (pam pincha) writes: >> >>I would also like to note that the claims have not been even slightly >>accepted. The comments made about the specimens would be highly unlikely >>given the unusual type of limestone they are found in. It is a very fine >>grained micritic limestone. It has such an even surface that it makes >>an excellant base for printing lithographic prints -- hence its common >>name of lithostone. To do what Sir Hoyle(who has little experience in >>micro-petrology) claims was done would be quite a feat indeed. > > What exactly does Hoyle claim to have done? Hoyle claims that the feather impressions were added later in a manner similar to the Piltdown Hoax. The method he proposes is a cement-like mixture. >>I'd like to see some electron microscope work (AND some >>micro-petrographic studies done first) these would show up differences >>that would be much more difinitive. > > Ditto! >> >>I'm not convinced that a cosmologist could tell the difference >>between different limestone types that occur naturally - let alone >>if cement had been used. >> > Hold it! Isn't cment essentially just crushed limestone in >water?!?! If he is trying to claim that part of the specimen is in >artificial cement he is on shaky ground! I doubt *I* could tell the >difference between fine grain cement and micritic limestone, and I am >more qualified in that area than Dr Hoyle. There is a definite difference between crushed regular limestone and micrite -- especially the micricrystalline quality of the limestone discussed here. Remember micrite rarely has what could br called a good granualr texture -- hence the microcrystalline texture it's usually described as in the literature. Crushed cement is not just limestone. It contains alumina,silica,iron oxide and magnesia that haas been burned together in a kiln,then finely pulverized. That is the only way it will react with water to form the hard matrix. The limestone has to undergo a calcining process (heating to high temperatures ,just below fusing, in order to drive off the volatiles and/or oxidizing the material) in order to change it to lime. Lime is the major reactant with water. After all these changes the calcium carbonate would not be the same structure or make up that a fine micritic ls would be. This would show up uder a microscope. One would have to be a carbonate petrologist to tell, but it is distinguishable. (Note I am basing this on the fact that the limestone that these fossils are found is an unusually distinctive limestone that would be very difficult to fake. A detrital limestone would be difficult. But all descriptions I've run across indicate that this limestone is nearly a pure micrite. This means almost no allochems or detrital material in it. Have you run across anything to the contrary?)(Carbonates are a favorite field of mine. Any info would be appreciated.) P.M.Pincha-Wagener