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Author Topic:   Is Radiometric Dating Really that Accurate?
gene90
Member (Idle past 1957 days)
Posts: 1610
Joined: 12-25-2000


Message 22 of 114 (15948)
08-22-2002 8:08 PM
Reply to: Message 21 by Thunderbird
08-22-2002 7:08 PM


Who did the analysis and what methodology was used? In lava flows you can find xenoliths--fragments of rock from deep underground that are carried with the lava and so are much older than the flow.

YECs can make radiometric dating fail by doing such things as sampling xenoliths and taking only one data point, or discarding several datapoints for one spurious, irreproducible one.

Another problem with dating such recent flows is that the margin of error commonly is within a couple of million of years. If a flow is 100 million years old, and gives a radiometric age of 102 MY then that error is perfectly reasonable. But if a flow that happened yesterday gives 2 MY, YECs cry foul. It's really a silly argument when taken in the correct context.

[This message has been edited by gene90, 08-22-2002]


This message is a reply to:
 Message 21 by Thunderbird, posted 08-22-2002 7:08 PM Thunderbird has responded

Replies to this message:
 Message 24 by Thunderbird, posted 08-23-2002 1:53 AM gene90 has responded

  
gene90
Member (Idle past 1957 days)
Posts: 1610
Joined: 12-25-2000


Message 32 of 114 (16082)
08-26-2002 9:26 PM
Reply to: Message 24 by Thunderbird
08-23-2002 1:53 AM


[QUOTE][B]What reason is there to
believe that accusation?[/QUOTE]

[/B]

Because YECs are known for such. Also Austin's work is not peer-reviewed like real science is.

Since you narrowed it down to Austin I was able to find fairly detailed information about this "incident".

From TalkOrigins

[QUOTE][B]First, Austin sent young, low-potassium (and therefore very low in radiogenic argon) rocks to Geochron Laboratories, which specifically states in its advertisements: "We are not in a position to analyze samples expected to be younger than 2 M.Y." (Geotimes 1995-7). He did it anyway and specifically states in his paper that "No information was given to the lab concerning where the dacite came from or that the rock has a historically known age (Austin 1997)". This puts potentially large error-bars on the data and also opens his research to ethical questions. In response to the original post, Andrew MacRae replied "...all Austin has proven is that if you do something silly, and misapply K/Ar dating to rocks erupted yesterday, you get nonsensical age results" (MacRae 1998). Henry Barwood notes that "Bad measurements, like bad science, reflect only on the measurer (Austin), not on the measurement (the procedure) (Barwood 1998)." [/QUOTE]

[/B]

In the next paragraph it points out that Austin did mention that there were xenoliths present in the lava, and assured us that he avoided them. There is no satisfactory way for us to confirm that (this is why reproduciblity is important in science).

The article then points out that Austin has a history of botching radiogenic ages.

One final issue: an error of 350,000 years isn't so bad, that lab should be commended for a job well done, particularly considering the ridiculous circumstances.

[This message has been edited by gene90, 08-26-2002]


This message is a reply to:
 Message 24 by Thunderbird, posted 08-23-2002 1:53 AM Thunderbird has not yet responded

  
gene90
Member (Idle past 1957 days)
Posts: 1610
Joined: 12-25-2000


Message 39 of 114 (28262)
01-01-2003 7:24 PM
Reply to: Message 36 by Watson
01-01-2003 3:43 PM


quote:
Each part slaming into the glacers forming the greatlakes

No impact craters, melts, or shock morphs of quartz.

quote:
Even NASA admits the mars rocks doesn't match anything
known on mars.

Quite the contrary the SNCs contain vesicles gas that match the Martian atmosphere. I also recall a match between x-ray spectrometry from the Mars Pathfinder rover and the SNC suite. I've been trying to find that chart recently.

Plus, you are trying to infer that the SNC achondrites originated on an asteroid, which is impossible because they are basalts. Basalts only occur on differentiated bodies, asteroids lack sufficient gravity to differentiate. Plus they don't fall in large quantities, the largest so far is Nakhla (fall, 1911) with a total known weight of only 40 kilograms.

quote:
And guess where you can
find these types of meteorites? answer. around the mediterranean
and the greatlakes area.

You can also find them in Chile (Imilac) Antarctica (Yamato 8451; Theil Mountains) Kansas (Bremen) Russia (Brahin) Australia (Huckitta; Molong).

I have read of meteorite finds being concentrated by type in certain geographic areas, because soil conditions favor preservation of a certain class or because finders are only taught to recognize a particular type. But I have never heard of any pallasite concentration around the Great Lakes or the Mediterranean Basin.

quote:
The areas in general are
contaminated with still today radioactive rocks that are not from
this earth and are from another timeframe.

We would notice that with a Geiger counter.

Plus, don't you find it odd that there are no radioactive meteorites falling today?

And finally, just scattering radioactive elements across a sample won't necessarily make a young specimen look old. If you happen to be scattering more radioactive parent element you will actually make a specimen look *younger* than it really is. That hypothetical asteroid would have to have exactly the right elements in exactly the right concentrations. And those concentrations would be immediately skewed as they began to spread across the planet.

Then you have the observation that meteorites and lunar samples still give old ages. How do you explain those?

[This message has been edited by gene90, 01-01-2003]


This message is a reply to:
 Message 36 by Watson, posted 01-01-2003 3:43 PM Watson has responded

Replies to this message:
 Message 40 by Watson, posted 01-01-2003 11:11 PM gene90 has responded

  
gene90
Member (Idle past 1957 days)
Posts: 1610
Joined: 12-25-2000


Message 42 of 114 (28277)
01-02-2003 2:00 AM
Reply to: Message 40 by Watson
01-01-2003 11:11 PM


quote:
The glaciers move north to south

I checked a field guide on the Finger Lakes region, yes I'll agree that the glaciers were flowing N-S there.

I did an online search for the origin of the escarpment when the guide failed to discuss it and could find no reference to it being carved by glacers. Instead it seems to be an erosional remnant in a syncline.

http://www4.vc-net.ne.jp/~klivo/gen/geology.htm

If that were a crater there should be shock products throughout the structure, a lens of impact breccia beneath Michigan Basin, and lots of faulting in the escarpment itself.

quote:
I have had a lot of spectrographic analysis done on glass rocks found in lake erie and the boys at NASA said spectrographic
analysis is not reliable is this true?.

Could you describe these glass rocks a bit?

Who did the analysis? Also, which NASA facility was involved?

quote:
An asteroid could be a planet that has never formed

That's the current thinking. But if that's the case then most wouldn't be able to differentiate enough to form a basalt.

If there were meteorites falling that were consistent with Earth's mantle material then I would be more open to basalt asteroids.

But I've looked into this a little further and found that now some scientists are arguing that Vesta is partially covered by a basaltic rock, based on HST observations.

quote:
or a large
piece of a planet that has been distroyed

It's very unlikely that there are any asteroids formed by destroyed planets because achondrites are so rare. Most meteorites are undifferentiated. If there were meteorites with compositions like solid slabs of olivine or peridotite falling in large numbers I would be more open to the possibility.

quote:
So why couldn't basalts occur in asteroids?

Most asteroids are too small to retain enough heat and hold a graviational field significant enough to allow differentiation. I think I may need to read up on Vesta to see what researchers are claiming has happened there to facilitate production of basalt.

This is a surprising find and you'll notice that people in the following article suggested that perhaps it should be thought of as a small planet.

http://www.xtec.es/recursos/astronom/hst/hst2/9540.html

quote:
Next Draw a line from Brenham kansas east through lafayett Indiana

I see that that the three line up but I don't understand the significance. Brenham is a pallasite and Lafayette is an SNC. Brenham is often terribly weathered and Lafayette is fresh. And also, Lafayette was found in a Purdue collection. Nobody knows where it was found (though I wish I did!), it was brought to Lafayette by human agency from some place unknown. There has even been speculation it may be a Nakhla that was misplaced (but it has been discredited by lab work). For this linear trend to be valid we must assume that the rock was found right there in Lafayette.

But that itself doesn't necessarily say much. So many meteorites are known that I can use them to draw lines to any place I want.

Where does Atlantis fit into this?

And I still don't understand why there would be any sort of "politics" involved with this. The Sudbury impact structure is only a few hundred miles from there.


This message is a reply to:
 Message 40 by Watson, posted 01-01-2003 11:11 PM Watson has responded

Replies to this message:
 Message 43 by Watson, posted 01-02-2003 5:59 AM gene90 has not yet responded

  
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