CompuServe Thread

Thai Tektites,

6 messages in this thread
#136909From: Doug MitchellJul 9, 1994 2:43 PM
Hi, Adrian– It is easy to figure how the NASA people might link tektites to the Moon, but I wonder how they figure volcanism instead of a lunar impact? Just because they found no crater? It seems any signs of impact in the tektites would likely be obliterated if they are melted during re-entry into Earth's atmosphere. And since volcanism on the moon is not clearly established (I think; see my replies to Tom and Guy in this thread), I would think lunar impacts would be the preferred explanation for Thai tektites. –Doug
#136969From: Alan MitterlingJul 9, 1994 11:08 PM
Hi everyone, I started following this thread a little late so I probably should not add my two cents worth but I can't help it <<G>>. Surely you don't suggest that the moon is the source of tektites? Nearly all of the experts agree that the moon is no longer considered the source for tektites. Except for just a handful who won't give it up and don't seem to be listening to the known facts. The absence of silica-rich lunar rocks effecticely rules out a suggested lunar origin for these objects! These objects have an Earth origin. In some cases the parent crater _is known_. An example of this is the moldavites recovered in Bohemia, Czechoslovakia are most very likely from Ries Crater in southeastern Germany. Tektites contain mostly terrestrial material, although some meteoritic spice <<G>> is contain in just a few. I am by no mean an expert of this subject but have read abundant books on the subject of meteorites where tektites are given a few pages. It may be that the source of some of the information on tektites you have read are old and there fore out dated. I do know the widely held idea of the origin of tektites no longer include the moon. Its your shot now <<G>>, go easy on me. –AL
#137032From: Doug MitchellJul 10, 1994 6:02 PM
Hi, Al and folks– Adrian was talking specifically about Thai tektites (and likely all of those from southeast Asia); he mentioned hearing of a NASA study that related their composition to moon rocks. _If_ that was a post-Apollo result (?), a lunar origin for _some_ tektites would still seem to have merit. How are asteroids as sources of silica? With a lunar impact, perhaps part of the asteroid would mix with some of the moon rock and be ejected? Lunar volcanism might be able to sort out a small amount of silica from moon rocks generally poor in such, and preferentially throw the silica out of the Moon's gravity, though this would seem to need more than just a little outgassing. So where are the volcanoes? Could tidal stress really drive such processes? Might a major impact leave a magma reservoir and some true volcanism afterwards? The lunar maria are examples of such a thing, though they are way too old to explain tektites. I wonder if anyone has ever counted craters-within-craters to see if there are more of them than impacts would likely explain. Anyway, I am just fooling around with ideas not to be taken too seriously; my best guess is that some dealers find the old theories sell more tektites. –Doug
#137164From: Alan MitterlingJul 12, 1994 2:20 AM
Hi Doug and everyone, Probably the most compelling evidence (and refutable) of an Earth source, is the air bubbles that are found in tektites. These air bubbles are found in all tektites and are sealed by the glassy material they are made of. Scientists sampling these air bubbles find it samples the Earth's atmosphere. It is the rare gasses of Argon 38 – 39 that carry the signature and imply tektites are from impacts on Earth. I'm not taking this too seriously either. I just would not want someone selling me a Zagami (Mars Meteorite) when it was an ordinary meteorite. I have sold a few tektites and I would say one in three people think these are from the moon. I always tell them before selling them, that they are believed to be from impact craters here on Earth. I do get a lot of disapointed people that way. There still is a lot of mystery about these things. They still don't fully understand the forces that generate tektites. Also don't get me wrong. I am not implying anyone is misrepresenting tektites here. I believe we were trying to unravel some of the mystery that still exists! –AL
#137315From: Doug MitchellJul 13, 1994 10:55 AM
Hi, Al and folks– Bubbles of Earth air are indeed troublesome for lunar-origin theories of tektites. I wonder how possible it is that air bubbles would be inserted into a lunar tektite during entry into Earth's atmosphere? Old theories have a way of hanging around long after their demise. It is easy to imagine a dealer who only sells tektites as one of many wares, and spends only enough time to read an old book or label, or talk to someone who has read that old book, passing along an older theory to a customer. I would indeed be peeved at being handed an old theory presented as "fact" with my specimens. But even assuming tektites are from Earth does not steal much of their charm in my eyes, since they come from such spectacular impacts of objects from outer space. –Doug
#136975From: Adrian WhiteJul 10, 1994 2:02 AM
Hi, Doug, OK, so the moon theroy is a bit old hat, but in the Far East the people who sell tektites sell them like hot cakes, to all sorts of people, health freaks, new age whatevers etc. So I guess keeping the moon story going is good for business, even though the evidence is very weak, as is clear from the replies. By the way, when mentioned impact craters, I was reffering to Earth not Moon, and the region being South East Asia. I am only relaying hear say, so I wouldn't take it to seriously. I rekon the Earth impact to be the best bet so far. I'm only a novice so I better to some reading on this subject before further comment. Adrian P.S. Will post off all orders on my return to the UK in two days time