Dating Question For Members

OK, Dr Adequate, I've been thinking this through and doing some reading. So it appears that as per my OP question, what is being dated in order to determine the time the organism was deposited is the intrusive igneous rock which is above the fossil.This seems to imply that the igneous rock likely originated from the earth's mantel and rose by plate tectonics so as to be above the fossil.So it appears that what would ultimately determine the age of the fossil is whether the plate tectonic activity was relatively sudden via catastrophe or over the millions of years, inch by inch.What think you?

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BUZSAW B 4 U 2 C Y BUZ SAW.
The Immeasurable Present Eternally Extends the Infinite Past And Infinitely Consumes The Eternal Future.

What hubris! How can you post stuff like that, Buzsaw? Your original post did not even hint at dating of igneous rock. You weren't even close. I think you've demonstrated how incredibly difficult it is to get anywhere with one foot nailed to the ground.If a fossil is between two layers, how would your assumptions affect dating of the fossil? I'm asking that you explain how the catastrophe model would affect the dating of each of the two layers. In your explanation, please at least attempt to identify the mechanisms that affect layer dating.Some hints. The birth date of igneous rock is assumed to be the date the rock solidified from lava. Please remember take into account the direction in which you want scientists dates to be wrong.

How could a flood alter elemental isotopes? I know you've long asserted this as a result of a putative Biblical Flood - that somehow the Pre-Flood Earth had different ratios of various elemental isotopes than the Post-Flood Earth - but I've never seen you explain exactly how plain water is supposed to do that. This seems like something you assume the Flood can do because you have to assume it, because you have to have a Pre-Flood Earth with different isotope ratios in order to queer the radiometric dating, which always has been the strongest evidence against a short history for life on Earth.In order to change the ratio of isotopes of a material, at least one of the following has to happen:1) Sufficient time has to proceed to allow radioactive decay to eliminate the more unstable isotopes.
2) Nuclear reactions have to occur that result in fission or fusion of nuclei.It's possible, mechanically, to separate isotopes by weight, but that doesn't really alter isotope ratios, it just moves them around in space.Please note - plain water can't cause nuclear reactions. It's all very well and good for you to imply that the Great Flood somehow changed the isotope ratio of the entire Earth, but what could possibly be the explanation for how water was able to do that?

The igneous material above the fossil is younger than the fossil. The igneous material below the fossil is older than the fossil. It doesn't matter how quickly they were deposited.It is possible for younger igneous material to intrude below the fossil but it's pretty unlikely that it would appear as a layer, neatly inserted between sedimentary layers. Even if it did, it would make the fossil appear younger, not older.

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If you have nothing to say, you could have done so much more concisely. -- Dr Adequate

I think you are wrong.It does not matter if the intrusion was slow or fast. What is being measured is the time elapsed since the intrusion changed states from fluid to solid.And if it is above something then by definition it will be younger than material that is below unless the whole formation is disturbed and THAT will leave clear evidence of the disturbance.

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Anyone so limited that they can only spell a word one way is severely handicapped!

This is incorrect, they are being dated by extrusive igneous rock. Intrusive rocks would be useless for this purpose.

Hi Buz,I'm not participating in the debate, please do not reply. I just want to help move the discussion forward by providing a very clear description of how the layers being talked about are formed. Here's a very common scenario:

1. A volcanic eruption deposits a layer of lava. The lava layer cools and solidifies and becomes extrusive igneous rock. The igneous rock can be dated by a variety of radiometric techniques.
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2. After that, sedimentary layers are deposited on top of the lava layer, and these layers contain fossilized remains.
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3. And lastly, another volcanic eruptions deposits a layer of lava on top of the sedimentary layers, and this lava layer also becomes extrusive igneous rock that can be dated radiometrically.

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--	Percy
	EvC Forum Director

Well my first thought is to wonder what you can have been reading to end up with your brain that full of nonsense.How the heck did plate tectonics get involved in this?

Intrusive rocks aren't necessarily completely useless. If you have an intrusive rock sticking up through a sedimentary layer then it is:* Younger than the sedimentary rock if it intruded into it, and
* Older than the sedimentary rock if it is a buried outcrop.Now it is possible to tell which it is: the presence or absence of contact metamorphism would be one clue; its shape and the way it fits into the sediment would be another --- a sill, for example, would be a sign of intrusion.Of course, this has nothing to do with Buz's blather.Edited by Dr Adequate, : No reason given.

From what I read, the intrusive igneous originated from the hot mantel of the planet's core. I would assume that plate tectonics would be one cause of the rise of the intrusive igneous from the mantel to above the fossil. How else does it end up above the fossil sediment being studied?

Plate tectonics doesn't move it, and when it rises it's magma, not rock.

Plate tectonics are caused by the same forces that cause lava to extrude and magma to intrude.

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If you have nothing to say, you could have done so much more concisely. -- Dr Adequate

Which raises more questions. What forces cause the lava to rise to the extent that it raises the plates?How far above the planet's mantel does the magma rise before it becomes cooled enough to harden into intrusive igneous rock?If it is the cooled magma rock that is tested by the radiometric dating, does it date differently than the rising magma and if so, why?

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BUZSAW B 4 U 2 C Y BUZ SAW.
The Immeasurable Present Eternally Extends the Infinite Past And Infinitely Consumes The Eternal Future.

Hi Buz, It does not matter where the igneous material originated.It did not flow up through cracks in the crust and slide in between the fossil layer and the layer above it. That would be intrusive and that is not the kind of layer we are talking about that is used to date the fossil.Picture a situation where there has been a volcanic eruption and a layer of ash covers everything, on the surface, the top layer.Many, many years later the area where that ash layer is, is flooded and becomes the bottom of a lagoon in a shallow sea. Animals that live in the sea die and some of them become buried in sediment and eventually become fossils.Many, many years later the sea dries up and the fossil layer are on the surface, the top layers. There is another volcanic eruption and this time a layer of lava covers the fossil layer and it is now the top layer.We can date the ash layer that is under the fossil layer. And we can date the lava layer that is on top of the fossil layer, so we know that the age of the fossils has to be between the age of the ash layer and the age of the lava layer.Do you understand what I am saying?

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Tactimatically speaking, the molecubes are out of alignment. -- S.ValleyWhat if Eleanor Roosevelt had wings? -- Monty PythonYou can't build a Time Machine without Weird Optics -- S. Valley

The plates don't "rise" per se. They "float", as it were, on the magma. The weight of the plates forces magma up into cracks in the plates. (Think of walking on a frozen-over puddle. The ice cracks and water comes up through the cracks.) The magma can harden inside the rocks of the crust, in which case it is an intrusion, or it can harden outside the crust as lava, in which case it is an extrusion. Geologists can tell the difference between an intrusion and an extrusion. Only the extrusions would be used as dating layers. The rate of cooling would depend on the initial temperature of the magma/lava, the temperature of the surrounding material, etc. My guess is that lava on the surface would cool more rapidly than magma below the surface.But it's the sequence of the layers that matters, not the rate of cooling. The bottom layer would have cooled to the point of closure before sedimentary layers were deposited on top of it, so the lower layer will always date older than the higher layer.

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If you have nothing to say, you could have done so much more concisely. -- Dr Adequate