Re: Meaning of the Geological Column

Zoe wrote:

On Wed, 14 Mar 2007 15:01:34 GMT, John Harshman
<jharshman.diespamdie@xxxxxxxxxxx> wrote:


Zoe wrote:


snip>

the question is WHAT cycles of deposition were there to cause later
layers to lithify lower layers? Repeated flooding, with each event
occurring over millions of years? How would a tilted or even
horizontal layer lithify if there were as yet no layers above it to
compact it?

Agreed. there must have been deposition above any layers that were
lithified. Note that your idea of "flooding" is not necessary to explain
deposition. There is all sorts of transport by water that couldn't
reasonably be called flooding, and all sorts of wind and even gravity
transport too.

how does this answer the question of: How does a layer lithify if it
sits for millions of years with no new layer above it to compact it?

It doesn't. Nor does it answer the question "Why do we wear shoes on our
heads?"

So if a deposition sits out in the open for millions of years, with no
layers on top of it to compress it, it would more likely erode away
than turn into solid rock. Right? And the same thing would happen to
the next deposition.

Yes.


okay. So why would you assume that there are millions of years
between layers that you now concur could not have lithified?

No. I really don't understand what you're trying to say here. Which
layers do you think never had sediment on top of them?

In general something has to push the excess water out, and in
general that's pressure from layers above. So if you really want you can
add an extra step of non-lithified layers.


I don't want to add anything just to make it work on paper. I want a
real-world answer.

If, for instance, a layer of transition limestone lays around for
millions of years during the Silurian period, what prevents it from
eroding away?

Actually, much limestone is deposited as rock. Let's try shale instead.
The answer to that question is that nobody is supposing that any such
layer is lying around for millions of years without either eroding or
having something deposited on top of it. I have no idea where you get
this idea.

Why would you expect it to remain in place over
millions of years until water again covers this loose bed and deposits
a layer of "old red sandstone" supposedly marking the beginning of the
Devonian period?

I have no idea how you arrived at this scenario. I don't expect any such
thing.

3. Tilting of the lower layers.

not just tilting but sometimes literally turned on their sides.

That's a lot of tilting, eh?


4. Erosion of the tilted layers into an approximately horizontal surface.

that's the question. Erosion does not seem to produce a horizontal
surface. More like ragged ups and downs, depending on the varying
means of erosion and what particular elements hit what particular
spots in the layer.

Actually, over time it does give you a fairly horizontal surface. It
might start out raggedy, but sediments will be deposited in the low
spots which will then erode less, and the high spots will be
extra-exposed and will then erode more. Anyway, the erosional surface is
only more or less flat.


see (will probably wrap):

http://www.earthscienceworld.org/images/search/results.html?begin=0&num=1&numBegin=1&Category=&Continent=&Country=&Keyword=Erosional%20Surfaces

erosion does not appear to be more or less productive of flat terrain.

or look at this:

http://www.geo.umn.edu/people/grads/hasba002/sandbox_stats/ObliquePhotos.htm

doesn't look flat to me.

I agree that erosion can produce non-flat surfaces temporarily. How
about a photo of the Canadian Shield?

5. Deposition of sediments on top.


finally..



6. Lithification of those sediments.


again, what would cause this next deposition to lithify if, for
millions of years, there was not another layer deposited on top of it?

Who says that another layer isn't deposited for millions of years?

those who identify the various layer types as belonging to certain
periods consisting of millions of years, they are the ones that say
that.

No.

You know, like the Cambrian period doesn't get its
Ordovician-period layer until 57 million years later, and the Silurian
period of layers don't come along until 23 million years later, and
the Devonian period of layers don't get laid down until 58 million
years later. Or do I misunderstand the time line?

You misunderstand something. Not sure what. The timeline is continuous.
The Cambrian is not a single week. It's all 53 million years. The
Ordovician starts as soon as the Cambrian ends. So there's no need for
Cambrian sediments to sit around, uncovered, for millions of years
waiting for the Ordovician to come. There are many places in the world
that show continuous deposition across the Cambrian/Ordovician boundary.
Of course deposition need not be continuous even within a period, and
generally isn't. There can be many episodes of deposition and many
episodes of erosion within a period. And any given site is generally
undergoing one or the other at any given moment.

As to your explanation for what an inconsistency is -- okay, I see
what you're saying. The inconsistency that McBane was talking about
was the missing part of the tilted layer; not an entirely new and
missing layer, but the peaked part of the tilted layer.

I think you have some bizarre misconception of what constitutes a layer.
The inconsistency was the unconformity, the erosional surface in the
tilted layer that indicates missing time.

okay, if you wish to rephrase it in your own words, fine with me. We
are both saying the same thing.

If so, you are saying it so badly that I can't recognize it.

Not only are parts of the
tilted layers missing, but clearly while they were being eroded nothing
new could have been deposited in that spot. You can't have both erosion
and deposition in the same spot at the same time.

except we are not talking about "at the same time" here, but a span of
millions of years in which erosion could occur, deposition could
occur, and further erosion could occur. A lot of things can occur in
millions of years that we have no idea of, including the sprouting of
a wing on a dinosaur.

OK, now I have no idea what scenario you're trying to promote.

So I went and found some photos of these angular uncomformities. More
questions are raised than answered, however. Look at this one:

http://en.wikipedia.org/wiki/Image:Vallisvale.jpg

That's a very pretty unconformity.

doesn't the top appear to be cleanly sliced off rather than raggedly
eroded away?

Top of what? Do you mean the erosional surface of the unconformity or
the present-day erosional surface? They both look pretty flat to me.

The explanation given for a missing layer is that it eroded. How
about the possibility that it could have been sliced off through an
onrushing cataclysmic action.

Onrushing cataclysmic actions don't do that sort of thing.


have you ever witnessed the power of water pressure or wind speed?

Yes I have. They don't seem to make especially flat erosional surfaces,
compared to any other process.

And besides,
you are trying to explain both the tilted and horizontal bits, above and
below the unconformity, by a single flood, right?


no, not necessarily a single flood, or even a global flood. I said an
onrushing cataclysmic action or event.

Yes. "An" refers to one event. You need several events here: one to
deposit the lower layers, one to erode them after they're tilted, and
one to deposit the upper layers. And it seems that they need to be
widely separated in time. But you only have a couple of thousand years
to work with, maximum. Right? Remember that it all has to be done before
anyone who can write notices. How do you accomplish all my 6 steps so
rapidly in succession?

But remember that
6-part sequence above? All except number 6 would have to happen during
that brief flood. This is physically impossible. It would take many years.

thousands or hundreds or years can do it. You don't need millions of
years.

Really? How do you tilt the lower strata so quickly without shattering them?

As a matter of fact, in order for lower layers to lithify, I
think you would need to have layers laid down fairly rapidly, in
quick, short-term events, as water covers an area.

Why?

And what about the area left vacant at the angle where the rocks tilt?
What fills that area?

I have no idea what you're talking about there. No area is left vacant.

tilting or uplift of a layer would cause one end to rise up higher,
leaving a vacant area. What fills the area left vacant by the uplift?

There is no vacant area. The tilting involves blocks or folds that go
way down through the crust, down to regions that experience plastic flow.

I think a better answer, instead of uplift, would be a slippage of a
layer (through an earthquake or landslide maybe) such that the lower
end sinks deeper into the earth. There would be no vacant area left
in that case.

That's right. In your naive view, what would be needed would be for the
rocks below to get out of the way, presumably into some vacant area that
had already existed. This scenario is no less ridiculous than the one
you had proposed before. But in fact we can often say what happened. For
example, the Sierra block has risen on its eastern side and sunk on its
western side, which is why the eastern side sticks up and is eroding,
while the western side is buried under thousands of feet of sediment.

Here's the original scenario, horizontally laid layers:

----------------------------------------
----------------------------------------
----------------------------------------
----------------------------------------
----------------------------------------

would a volcanic eruption cause tilting?

It would cause some local tilting. Intrusion of a sill or suchlike would
cause tilting, but both would be on the scale of a few meters. That's
not the reason for angular unconformities.


I'm not sure I can see how
an eruption would tilt rock. Wouldn't it merely intrude as follows:

---------------- ----------------
-------------- ---------------
----------- -------------
--------- -----------
----- --------

Where does the rock that gets intruded go? Now in fact some of it would
be melted or included as xenoliths. Never mind, though. This is not the
cause of most tilting.


how about an earthquake, where the earth beneath layers of rock gives
way so that the original horizontal layers tilt at an angle? This
could happen in an instant. And, from the site below, it appears that
the layers continue on down under the earth.

http://en.wikipedia.org/wiki/Image:Vallisvale.jpg

How did that happen? I'm intrigued.

Not one earthquake, but perhaps many over a long time. Tilting of this
sort has several potential causes: Block faulting or syncline/anticline
formation due to continental-scale compression are the big ones.


Also, erosion doesn't seem to be the best answer, considering that
erosion is not a consistent, evenly occurring process, where the top
of a rock layer flattens out. The eroding particles appear to come
from the sides, as in the following:

Eroding particles? From the sides? What you see here is an angular
unconformity in which the erosional surface has itself been tilted
sometime after formation. Remember that the rocks both left and right of
the unconformity were originally horizontal. By the way, it also looks
here as if the erosional surface isn't quite flat, and that the younger
(left) sediments fill some holes in the older (right) surface.


http://geoweb.gg.utk.edu/courses/HistoricalGeo/angular.html

gravity seems to be a factor in erosion here. If that continues, then
I would expect that the next thing you'd see is the serrated edges of
the sideways layers, showing at the top.

Of course gravity is a factor. That's why you tend to get a flat
surface: the parts that stick out experience faster erosion than the
parts that don't. I don't know what you think you're looking at in that
picture, but the unconformity is the surface that's at about 80 degrees
in the center of the picture. And looking at the current erosional
surface above the road cut, that looks quite flat too.

Or this one:

http://marlimillerphoto.com/SrU-01.html

where the rocks have definitely been turned on their side, and the top
surface doesn't show the kind of erosion that creates a flat top.

Another angular unconformity where the erosional surface isn't
horizontal. Yes, the recent erosion here hasn't produced a flat surface.
But if it goes on long enough, it will -- more or less flat at wave base.

long enough, like millions of years? How did this rock lithify in the
first place?

Presumably it was buried way down, and all the overburden has been
removed by erosion.

Compare that, again, to the "inconsistency" or top of the tilted layer
in the photo below. The top of the tilted layer does not look like
the result of erosion, either. It is too clean a slice.

http://en.wikipedia.org/wiki/Image:Vallisvale.jpg

This is because you don't know what erosion looks like. A snapshot of
erosion in process doesn't look the same as what it looks like when
erosion stops.

see the links I've added above as to what erosion looks like. Doesn't
look flat to me.

It will.

Do you have, somewhere, some real-world series of stacked layers that
contain the types of fossils that generally, in succesion, span life
forms from trilobites, starfish, Pterygotus, Ichthyostega, Dimetrodon,
Placodu, Archaeopteryx, Tyrannosaurus, Brontotheres, Sabre-toothed
cat, Deinotherium, woolly mammoth, ending with primates?

This is the silliest sequence ever imagined. It's not an evolutionary
sequence, it's not a temporal sequence. It's just a random list of
names.

the above list of names is not random. Apparently, you're not
familiar with your own theory's evolutionary tree, John.

Or perhaps you can pick out random words without understanding what they
mean.


I picked
them from the following site which gave the types of speces found in
each of the periods of the eras, going from trilobites on up to the
present-day species:

http://www.bobainsworth.com/fossil/palaeozoic.htm

http://www.bobainsworth.com/fossil/mesozoic.htm

http://www.bobainsworth.com/fossil/cenozoic.htm

All very nice. Was it intended to be a temporal sequence, not an
evolutionary one?


the evolutionary sequence IS a chronological sequence.

You are incapable of clarity. You picked a bunch of random species and
larger groups that happen to be found (though in most cases not
exclusively) in particular periods. It's certainly not an evolutionary
sequence. It's not even a temporal sequence, since there are starfish
today and primates in the Cretaceous.

If so, you should choose groups, at least, that are
unambiguous representatives of the periods, and don't extend into other
periods. Primates are known from the Late Cretaceous to the recent, for
example, and are not the culmination of all time.

you still have not answered my question of where do you find these
higher-level fossils stacked so as to corroborate the independent
notion of evolutionary theory.

There are too many false assumptions in that question for it to be
answerable. Here are some of them:

1. You suppose that this is an evolutionary sequence when it most
certainly is not.
2. You assume that corroboration of evolution requires there to be some
linear sequence, which it doesn't.
3. You assume that in order to put fossils in sequence we need to find
them stacked vertically above each other. But we don't need to do that
if we have first constructed a geological column and know which layers,
in different places, are younger or older.

However, there are in fact many places where fossils from multiple
periods appear vertically stacked. The Grand Canyon is one such
prominent place.

I will just note that your second-listed group is still around
today, and that there are primates older than the oldest known
sabre-toothed cat.



Your position is that fossils in rock strata serve as evidence for
evolving species; that after these findings were made, then
evolutionists came along and merely recognized the ascending order and
interpreted such a progression as evidence for evolution of the
species from simple to complex. So please for this evidence from the
real world. Where have fossils beyond the shell level, been found in
this ascending order?

Once again you make the false assumption that biostratigraphy has
something to do with evolution.

John, stop backing away from your own theory. You're trying to
divorce evolution from the fossil succession in the same way you guys
divorce evolution from abiogenesis. I expect one day you will divorce
evolution from evolution because none of it makes any sense.

No. You just don't understand anything here. I can't tell any more what
you're trying to talk about. Have we left biostratigraphy behind? Do you
now want to talk about evolution? I have no idea.

I have been questioning how biostratigraphy (the fossil record that
comes with it) relates to evolutionary theory.

And I keep telling you it doesn't, at least not in the way you imagine.
Biostratigraphy receives no input from evolutionary theory. However, it
helps correlate rocks, and knowing the ages of rocks helps evolutionary
theory. In other words, any interaction is just in the opposite
direction from what you seem to be imagining.

I have early on changed and acknowledged that biostratigraphy was
ongoing before the theory of evolution came limping along. Let me
repeat.

I have acknowledged your claim that the fossil succession was firmly
in place before evolutionists came along and interpreted the
succession as meaning evolution from a single common ancestor. So
stop trying to insist that I am still saying that the geological
column was developed by evolutionists. I have retracted that and
refined my position to say that evolutionists, in the later history of
the geological column, began to apply their interpretations to the
finds such that the final version of the geological column reflects
their understanding. And if you read the history, there was much
controversy before that happened.

If you read the history, this idea that the dating of any fossil depends
on evolutionary theory can be seen to be silly.

did you read what I just said. I do not hold you to my early mistaken
idea that the fossil finds depended on evolutionary theory. I am
asking what exactly are the fossil finds that evolutionists later came
along and interpreted to mean common descent.

Actually, common descent doesn't rely on fossils. The theory was
developed before we had a very good record of transitional fossils, and
the great majority of the evidence has nothing to do with fossils.
However, fossils do provide much useful information in support of the
theory. Much of this information has nothing to do with their ages, but
with their providing examples of intermediate conditions.

Stratigraphy is useful, though. For one thing, we can see that different
species appear at different times, all through the history of earth.
They have definite stratigraphic ranges, and do not all arise at once.
We can also see that the biotas of different periods are different from
each other, and that the biotas of periods close together in time are
more similar to each other than to those of periods that are more widely
separated. The modern world looks quite a bit like the Miocene, less
like the Jurassic, and much less like the Silurian.

And stratigraphy also provides extra corroboration for our phylogenetic
hypotheses. More inclusive groups should appear before less inclusive
ones -- we expect to see amniotes before mammals, mammals before
primates, primates before hominids, and so on. And statistical tests of
such sequences always show there to be a significant correspondence,
hard to explain unless our theories of phylogeny are pretty good ones.

That's why I contradict
you every time you say it. Let me repeat. No fossil is dated based on
any assumptions of evolution.

and let me repeat that I acknowledge that fossil finds were not
originally dated based on evolutionary assumptions. What I want to
know is how evolutionary assumptions went about using the fossil
record to mean what they say it now means. Where are the fossils of
higher life forms that you say have been found (before evolutionary
theory) and are so ordered that a progression from simple to complex
is observed? If you cannot produce that original ordering, then I can
only conclude that you evolutionists have come along and put your own
spin on the fossil finds.

This is silly. If you agree that index fossils are not dated based on
evolutionary assumptions, and that rocks are dated without evolutionary
assumptions, it should be obvious that those fossils that are dated
merely by the rocks they are found in can't be dated using evolutionary
assumptions. That is, the time sequence of no fossils can rest on
evolutionary assumptions. And certainly they aren't dated by any
progression from simple to complex.

Now in fact it's not clear what progression you're talking about. You
have been told many times that evolution doesn't require any such
progression, and it's hard to figure out what you mean by it. Which
fossils are simple? Which ones are complex? Is a human more complex than
a Deinotherium?

You persist in asking questions that contain too many false assumptions
to be answered. If I take away the false assumptions, it would seem to
take away the entire question, leaving nothing to address.

So to repeat: the ordering of fossils in time has nothing to do with an
assumption of evolution. And our understanding of evolution is not
strongly informed by the ordering of fossils in time either, though it
turns out that the order we find fits our theories of evolution pretty well.

Why can't you get rid of this? It's
preventing you from understanding anything that is said to you, and
renders your questions and demands nonsensical.

the questions seem nonsensical because you are still back at square
one, when I have long since corrected myself and moved on.

Where are you? I have no idea.

over here....where the light is.

Sorry, looks like you're in the dark to me. You appear to have learned
nothing.

Once again: index fossils are among the forms of evidence used to
correlate and order the geological column.

and once again, I am asking for index fossils higher than the level of
shells. How did they order the scattered fossils of vertebrates
through the shell index fossils, for instance?

This should not be difficult to understand. Shells appear at all levels,
including those levels in which vertebrates also appear.

if the same type of shells appear at all levels, then they cannot
serve as index fossils.

Not the same type.

And if you have different types of shells in
different layers, then do you have a reference stack that shows the
positions of shells from old to young?

Yes. That's what biostratigraphy does.

And do these shells show up
next to the dinosaur digs and bird excavations and primate discoveries
so that you can know for sure that these surface sites belong to the
period of that particular shell?

Yes. Though in fact many index fossils are not shells.

If so, I'd like to see references
and better yet, photos, of such confluences.

Then you need to look up the primary literature.

There are other
index fossils too. Mammal teeth can be good.

how does a mammalian tooth help you order fossils from simple to
complex?

Yet more false assumptions. It doesn't. It helps you place fossils in
time. The teeth in question are index fossils. Remember index fossils?

Pollen can be good.
Remember: all an index fossil needs is to be plentiful and widely
distributed in space, but narrowly distributed in time.

and that is what I want to see. I know if I were a geologist, and I
had found consistent index fossils that marked the excavations of
higher-level fossils, I would photograph the two together and present
this as concrete evidence that the two were deposited together and
therefore must have lived at the same time. But that index fossil
would have to be compared to a reference stack.

Why do you have to photograph the two together? What if they were found
in the same layer, but 100 feet apart? Wouldn't that do? But at least
you now have some inkling of how fossils that aren't index fossils are
dated.

Use of index fossils has
nothing to do with evolution.

but evolution has a lot to do with interpretation of the index
fossils. Don't try to divorce the two.

Here you are still confused. Evolution has a lot to do with the ages of
fossils, but not with finding out their ages, which is what we're
supposedly talking about.

I don't care to find out the ages right now. I just want the
sequence, from older to younger, relatively.

And it should now be clear how this is done. Biostratigraphy is one of
the several sources of information by which strata are correlated.

And those are determined by the ages of the
rocks they're in. One way to determine the ages of rocks is by using
index fossils. That doesn't mean index fossils have anything to do with
evolution, any more than a thermometer has anything to do with snow falling.


Once we have a geological column in order,
we can determine the ages of non-index fossils. The ages of fossils do
show vast transformations in biotas through time -- thus there are no
species in common between Cambrian and Recent. However, the ages of
fossils have very little to do with inferring evolutionary
relationships. Nobody gets together a list of fossils in order of age
and then uses that as evidence that this is also a list of ancestors and
descendants. Though in fact it's interesting and informative to see just
how well the order of groups in the fossil record fits the order
expected from phylogenetic analyses.

then you might want to warn your disciples of evolutionary theory that
they should not cling so desperately to a fossil record that, as you
say, has nothing to do with evolution.

I say nothing of the sort. I said that using index fossils to find the
ages of strata has nothing to do with evolution. The fossil record is
much more than index fossils, and fossils are much more than their ages.

the fossil record apparently depends on index fossils to pinpoint
position relative to older and younger. I'm asking for those index
fossils that pinpoint younger life forms that have been fossilized.

Google gives me lots of hits for "index fossil" and whatever geologic
time I put in. Try one.

And if the fossils are not stacked but scattered, then please for the
index fossils that place these scattered higher-level fossils in
ascending order.

Once again, what exactly do you mean by "ascending order". Does this
refer to time or to evolutionary advancement, whatever that is?

ascending order has to do with evolutionary advancement, as supposedly
observed to occur through time, starting from simple organisms and
ending in modern, complex organisms. You say that geologists (not
evolutionists or evolution-believing geologists) first observed and
noted a progression of fossils that later corroborated evolutionary
theory. Can you show me this progression?

There is in fact no general progression of increasing complexity.

oh-oh, it's happening already. You're divorcing evolution from
evolution.

No, what's happening is your usual misunderstanding of the basics of
evolution.

What are you going to do with all those pictures in your
textbooks that show a progression from simple bacteria to primates?

I will agree that primates are more complex than simple bacteria. But
are they more complex than theropods or trilobites? On what basis would
you make such a determination? What textbooks are you talking about, and
how do they show such a progression? This sounds like the linear scala
naturae, which is evolutionary nonsense. Humans are not the culmination
of evolution any more than any other living species is.

There
is a general progression of "more like current life", though.

whatever that means.

It means that the longer ago you look, the less like the modern sorts of
species you see. I believe I explained that pretty well below, if you
would only read.

However,
the average complexity of life is about what it was 2 billion years ago:
lots of bacteria. You might say that the complexity of the most complex
life has increased over time, but I'm not sure even that is true since
about the late Paleozoic, when land faunas assumed something like their
present diversity.

okay, let's put evolution over there with abiogenesis. What's left?

I have no idea what you think you mean there.

However, "more like current life" is pretty easy to demonstrate. Look at
the Cambrian fossil record: no modern species, hardly any modern orders,
and few modern classes. No life on land at all. Now look at the
Triassic. Some of the modern orders have appeared, though still no
modern species, and land life has assumed much of its modern character,
though the actors are quite different. Now look at the Miocene: almost
all modern orders, many modern families and genera, even a few species.
Life everywhere is of quite modern aspect, though again with differences
and with few species in common. That's a progression right there.

you're looking at variation and calling that progression?

No. "Progression" is your term, not mine. I'm looking at vast changes
through time and calling them evolution.

There are
certain breeds of dogs that will disappear because they are no longer
bred by dog breeders. If you find one of those varieties a thousand
years from now, will you declare that here is evidence that dogs were
evolving into some new genus? Or would you be reasonable and say,
well, that breed died out. Period.

Which breeds of dog existed in the Cambrian? Now in fact we find dogs,
even in the most generous meaning of the term to encompass wolves,
foxes, and such, only from the Late Eocene. Before that comparatively
recent time, there were no dogs at all. So something must have happened,
either separate creation of the dog group at that time, long after
creation of many other groups, or evolution from some ancestor. And in
fact there are Carnivora (the order dogs belong to) that are older than
that, just as we would expect. This is hard to reconcile with your
theory, that everything was created simultaneously a few thousand years ago.

I would like to see an example of a Tyrannosaurus,
for example, that is found in the same location as an index fossil
that has been relatively dated as belonging to a specific period. And
what determines that the particular index fossil is older or younger?

Index fossils are found in vertical sequences.

so do you have references to locations where the index fossils are
found in vertical sequences, all the way to the present day?

Is this another request for the entire geological column in one place?


okay, so you admit that there is no such reference sequence.

Of course there isn't. The geological column had to be assembled by
correlating different sections around the world. No single spot has the
whole thing. But these different sections can be correlated by the means
that have been explained to you already.

I
thought we had passesd beyondd that. Index fossils, like anything, must
be correlated across different sections. You have been shown how this is
done. No one spot has everything. Remember the various letter sequences
you have been shown. Now imagine that each letter is an index fossil.

are we back to the alphabet again? I think we're spinning our wheels
now.

We are doomed to continually spin our wheels while they are buried in
the mud of your incomprehension.

That's one thing that
makes them good index fossils. But this is a multi-step process, and
there are many means other than index fossils for dating strata. If you
look at any paleontological report on a new fossil discovery, you will
find that it is referred to a particular stratum in a particular
formation.

on paper, yes. It will say something like "Triceratops" was excavated
from a site noted as from the Cretaceous period. And that has been my
question all along. How do you determine that a site is Cretaceous or
Jurassic or Silurian, when it lies far away from the originally named
site?

You look up the reference in the paper, the one that tells you how the
formation was dated. There are many methods for this, all of which have
been explained to you.

poorly explained, if at all.

You just refuse to comprehend.

Absolute dating is generally by radiometric
methods.

okay, so you take refuge in radiometric dating. I'm done with that
aspect.

It's not a refuge. It's just the truth. Radiometric dating provides an
absolute time scale to the geologic column.

Briefly, a radiometric date of a stratum in spot A can be
correlated with spot B by using index fossils and such, which thus
assigns an absolute date to spot B.


And there will then be references to that formation that will
tell you how the age of the formation was determined. The ways in which
that is done have been explained to you many times.



Strata below
a certain level may be interrupted while strata above that level are
continuous.

how does interrupted strata demonstrate a missing layer?

The interruption might indicate erosion had taken place. Using an
illustration similar to McBane's from your original post:

aaa aaaaaaaa aaaaaaaaa aaa
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
cccccccccccccccccccccccccccccccccccccccccccccc
dddddddddddddddddddddddddddddddddddddddd
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

This is what we would expect to see if the upper layer - and any layers
above it - were exposed to erosion. Now, if this formation is submerged
again, a new layer would be deposited on top of the upper layer, filling in
the gaps.

hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
aaahhhhhhhhhhhhhaaaaaaaahhhhhhaaaaaaaaahhhaaa
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
cccccccccccccccccccccccccccccccccccccccccccccc
dddddddddddddddddddddddddddddddddddddddd
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

This would indicate that there had been a gap in deposition.


is this an example of a single location? If so, I understand and
agree with your illustration as an example of how to recognize erosion
of a layer for a localized stretch of rocks. However, if your example
is in answer to my question of how layers in North America are
identified as being from the same period as layers in Europe, then it
doesn't add up.

True. For any time after the opening of the North Atlantic, North
America and Europe will not share any layers (barring the odd iridium
anomaly). They might however share index fossils; many marine species
even today are found on both sides of the Atlantic. That's one way to
correlate layers on different continents.

so you can correlate layers up to the point of shells that are common
to both North America and Europe. Beyond that, it is guesswork for
the higher-level fossils?

No. There are other methods. Please stop using "higher-level", because
neither of us has a clear idea of what it means.

speak for yourself. My understanding of higher-level comes from the
drawings that evolutionists make of life forms that evolve from
low-level algae right on up to primates. If a primate is not at a
higher level of development than a bacterium, then we are definitely
on different pages and cannot communicate any more.

We have never been able to communicate. I will agree that primates are
more complex than bacteria, but you seem to require some linear scale
reaching from bacteria through humans, to which each organism can be
assigned a place. And there is no such scale.

.

Relevant Pages

  • Re: Meaning of the Geological Column
    ... am not questioning the correctness of the superposition of the layers. ... geological column together. ... A pattern of *specific* fossils is what allows the designation of the ... and so make the best index fossils. ...
    (talk.origins)
  • Re: Meaning of the Geological Column
    ... am not questioning the correctness of the superposition of the layers. ... geological column together. ... Once again you confuse biostratigraphy with evolution. ... Index fossils, ...
    (talk.origins)
  • Meaning of the Geological Column
    ... am not questioning the correctness of the superposition of the layers. ... geological column together. ... With respect to fossils, it ... If, as is the case here, layers that have the identifier ...
    (talk.origins)
  • Re: Meaning of the Geological Column
    ... layers to lithify lower layers? ... There's a lot of places where rocks just lie there without any significant ... contain the types of fossils that generally, in succesion, span life ... something to do with evolution. ...
    (talk.origins)
  • Re: Meaning of the Geological Column
    ... "the geological column" means. ... I don't understand what you mean by "some rocks from EACH period" are ... You can't do that worldwide for all layers. ... Among the characteristics of layers, of course, are the index fossils ...
    (talk.origins)