#Geologic Time Table
20 messages in this thread
– Reply to message #144215 (already scrolled)
>> So when I find a bed of gravel with out scratches and grit marks I
attribute it to a process where molten material is allowed to cool while
airborne or not in contact with a surface. There is no other process that I
have found that produces this condition.
When faced with the worldwide abundance of gravel in this condition we must
explain how this apparently common creation method could produce this
abundance. <<
If you use a microscope, you will see the scratches on the gravels you are
talking about.
GTL
– Greg Laden, Written 06-Sep-1994 @ 21:22:26
Using: Windows NavCIS PRO 1.25
No there aren't scratches.
What you see is a textured surface that composes the smooth surface that can
only be created by a shrinking cooling effect. Areas level with a grove running
around the perimeter, like an orange peal.
Even when the gravel has been scuffled up the glossy surface appears in these
depressed rings.
Take a look.
>> No there aren't scratches. <<
I have studied gravel surface features with various sorts of microscopy. You
have to use a variety of techniques to bring up scratches that are very small.
Usually, polarized light does the trick if you play around with it.
Electron microscopy also works. Take a look!
Cheers,
GTL
– Greg Laden, Written 08-Sep-1994 @ 10:42:36
Using: Windows NavCIS PRO 1.25
Greg
On my gravel samples the surface has a texture easily seen at even 20x. The
surface is one that has cooled and slightly shrunk. There is an orange peal
like surface with areas demarcked by a grove running completely around it.
Inside this small grove is a shiny mirror finish surface.
You want a sample? Email address and I'll mail you a couple of low g gravel
but you can find it anywhere in a gravel bed. Pick some small pieces from
within the bed. Grab a bit of the sand also, some of the sand is rounded and
glass like but most resulted from shattered quartz sprays.
Next time your out get fresh samples and take them home and look. It will
change your life.
Sincerely
Kamron
The history of the earth doesn't hang by gravel. It was covered by gravel.
Kamron
>> On my gravel samples the surface has a texture easily seen at even 20x.
The surface is one that has cooled and slightly shrunk. <<
The problem is that fine scratches don't appear even to be on the surface.
They are deflected by non-polarized light to appear to be off the surface, and
in fact, out of focus. So you can never see the fine scrateches at that
magnification in non-polarized light, and probalby not at that magnification at
all . The scrateches appear to be a gloss or shinyness at that level
– Greg Laden, Written 09-Sep-1994 @ 10:43:17
Using: Windows NavCIS PRO 1.25
I've got some new samples from the Colorado river area at Columbus Texas.
Some of the dullest looking pieces have the most delicate structures. There
are fine crystal like appendages that are visible on the surface. One small
wash with a toothbrush and they would be gone.
No matter where I look in hundreds of pieces the surface is a crystalline
surface with shiny planes and glistening wet look undulating surfaces. There is
no wear on them what so ever. No planes ground or distorted. The surface even
if not shiny displaces a clean crinkly texture. Like fused glass.
As you look closer the surface gets smoother and smoother with crystals and
tinny sand glued to shiny planes.
There is an almost reptilian or variable orange peel look to some pieces.
There are pores in some material. The pours and deformations in the surface are
filled with other matrixes usually glistening. There are hairs and tufts and
fused electrostatic sand stacks sticking out at angles.
The incredible details on the surface prove that it grew a crystal like
structure at the surface including very fragile features.
Gravel has dents where impacts created depressions sometimes shell prints.
Flattened gravel and fused cracked gravel demonstrate plastic condition.
Gravel is not a product of erosion or grinding.
99% of all the Gravel I have looked at so far is not a product of erosion or
grinding. Most show no trace of any friction or wear on the surfaces.
The surface is preserved proof.
Samples there soon.
Kamron
Kamron,
Do you have any idea how long it takes to grow a crystalline surface in waters
that are entirely saturated with calcium bicarbonate?
Not geologic time – you can do it in a few months.
The presence of such dendritic growth only means that the gravel hasn't been
ground in the last year or so. It tells you nothing at all about it's long
term origins. Moreover, have you ever tumbled rocks? You can get as smooth a
finish as you want, just by picking abrasive sizes. Why do you feel that such
events can't happen naturally?
— Norm
Norman
All you have to do is look over the surface of gravel to see that the surface
has never been ground. It has textures and features that are complex with clean
crystal faces in crystals that are well imbedded in the mass. There are
crinkles and folds and tiny features all glossy shiny.
Most of the gravel I have inspected is this way it shows no wear none. Zip.
Nothing. THis can be seen at only 10x to 40x power.
Look at gravel yourself and then we will talk.
I look at it almost every night lately.
Kamron
Looking forward to getting them!
GTL
– Greg Laden, Written 12-Sep-1994 @ 11:00:24
Using: Windows NavCIS PRO 1.25
Got the samples, and will be looking them over during the next day or two.
GTL
– Greg Laden, Written 13-Sep-1994 @ 16:24:42
Using: Windows NavCIS PRO 1.25
Kamron
I've had a chance to look at the samples under various powers of Optical Light
Microscopy (OLM), but I probably won't get to look at them under SEM. (I don't
happen to have one in my lab, but maybe we'll run one or two later in the
semester if we have other samples going in).
I've also discussed this with a graduate student here, Sho, who is doing his
thesis on polish.
All but one of the stones you sent is almost certainly quartz. The other is a
piece of granite or gneiss (too small to tell by just looking at it) but the
piece is mainly quartzy stuff within a granitic matrix.
The surfaces all show some degree of gloss. Some of them, possibly all if
inspected closely enough, show carbonate encrustations, the result of being
embedded in a matrix with the appropriate materials.
The sheen, or gloss, which is visible on all the samples but to varying
degrees, is as I understand it the main point you are making. This kind of
gloss projects under most conditions as a shiny surface, except under the
greatest magnification. There are scratches on some of the surfaces as well.
The orange peel effect you mention is clearly visible on one of the surfaces.
It is interesting to note that the gloss is stronger on the outside aspects of
this surface than in the pits. Also, where a stone or two has a facet that is
less exposed, you see reduced gloss there as well.
This is all typical of what we see as resulting from erosional experiments,
where we put freshly broken material in a tumbler, or in use wear experiments
where we use a freshly made stone tool to, say, butcher up a deer and process
the hide, etc., or to process plants. The gloss is most commonly formed, by
the way, in processing plants with a lot of silica. And in fact, in streams,
etc., it is mainly the silica in the substrate that results in the polish
formation.
The polish is identified as erosional because it is more common on outermost
facing surfaces, at the semi-micro level in the orange peel pits, and at the
larger level around the facts, where they occur. It is also distinguished from
melting because in some cases the quartz crystal structure is clearly visible.
If the stone had actually vitrified, this structure would be obliterated or
would remain only vaguely and probably show distortion (I'm assuming that you
are suggesting that the glossy nature as a result of melting also accounts
partly or largely for the globular shape of the stones).
In the experiments we've done in our labs here, and experiments done
elsewhere, the striations that result in gloss on silica material (like quartz,
chert, etc.) are in the sub 1 micron range, accompanied by a small number of
larger striations which may be nearly 1 micron wide and up to tens of microns
long. The latter are visible on the samples you sent me, the former not
visible with the equipment I have available to me in my own lab (but I will
cart them along next time I go to the labs with the big mean machines in them).
I don't see anythin consistant with melting as causing the surface
characteristics of the stones you sent. The additional characteristics you
describe seem to be the result of calcrete formation (carbonates) on the
surface of the stones from the matrix. You are right in that this would
probably wash off at least partly, although this stuff can be pretty hard to
get off some times.
Hope this helps. More later if I can take closer obervations.
Cheers,
GTL
– Greg Laden, Written 13-Sep-1994 @ 21:08:34
Using: Windows NavCIS PRO 1.25
Greg
Hey I really appreciate the collaboration 🙂
You got to admit …..
Gravel is one of the earths most glossed over treasures.
The surfaces of gravel are complex.
I noted that the samples have these qualities…
In places the crystalline structure is perfect.
There are grove systems like shrinkage cracks.
They could be formed of globs of liquid masses.
They display frozen examples of oblong, flattened, dented, and shattered
shapes.
Gravel taken from a bed along a fault has a good chance of having no erosion
or scratch marks anywhere.
The examples I gave you were in a bag all together so they received a bit of
scratching but should be 99.99% scratch free.
So …… the crystalline and smooth surfaces cannot be the product of
erosion or polishing. If so lets see you come even close to duplicating any one
of the billions of textures that exist on all the gravels of the world.
The Theory is
Gravel was belched from the earth in molten globs. The class or type of gravel
depends on the depth of the source materials. The sands they are found with are
condensed quartz and other materials with smooth sides and intricate features.
Greg … feel the force Greg ……go with the Force… :)))
Kamron
Want a box of gravel?
>>
Want a box of gravel? <<
No thanks, I've already got one!<g>
– Greg Laden, Written 15-Sep-1994 @ 10:18:36
Using: Windows NavCIS PRO 1.25
Greg – A simple acid wash would remove and carbonate film, as you are well
aware. I suspect that it partly accounts for the "gloss"
Michael
Hi, Greg–
>> it is mainly the silica in the substrate that results in the polish >>
formation
I think you are saying that only quartz is well-polished in these gravels? I
wonder what makes quartz (or any other mineral) more capable of a fine polish
than another mineral. What is a polish anyway? I have a very vague memory it
involves a melting of a very thin surface layer.
–Doug
>>
I think you are saying that only quartz is well-polished in these gravels? I
wonder what makes quartz (or any other mineral) more capable of a fine polish
than another mineral. What is a polish anyway? I have a very vague memory it
involves a melting of a very thin surface layer. <<
Ah, you bring up some interesting points. Among these stones, there are
quartz pieces that are more and less polished. The granitic stone is not
polished.
The issue of surface melting (called the "silica gel effect") is interesting.
Our student here, Sho, has demonstrated that it may not actually be what
happens with silica. He has shown that polish is instead wear and erosion with
no silica "melting" in at least some cases, and he's published his results. To
my knolwedge, the "other side" of the issue has not yet responded, so the jury
is still out, as it were.
Cheers,
GTL
– Greg Laden, Written 15-Sep-1994 @ 10:20:42
Using: Windows NavCIS PRO 1.25
Hi, Greg–
If the granitic gravel shows no polishing, how about any quartz grains at the
surface of the granite (or whatever)? Maybe the surface is just younger – I am
guessing that as they weather, granite pebbles will be continually losing
faster-weathering mineral grains and thus losing their whole surface more often
than quartz pebbles, constantly returning to an unpolished surface.
"Silica gel effect" does not suggest anything like surface melting to me,
seeming to refer to some dissolving and redeposition or hydration and
dehydration effect.
–Doug
>> If the granitic gravel shows no polishing, how about any quartz grains at
the surface of the granite (or whatever)? Maybe the surface is just younger –
I am guessing that as they weather, granite pebbles will be continually losing
faster-weathering mineral grains and thus losing their whole surface more often
than quartz pebbles, constantly returning to an unpolished surface.>>
I think you are absolutely right.
<<"Silica gel effect" does not suggest anything like surface melting to me,
seeming to refer to some dissolving and redeposition or hydration and
dehydration effect. <<
The SGE is something that happens quickly and while hard materials are
contacting the surface. It is aparently not exactly melting, as you suggest,
but does act as though the surface is melted.
Our student got into this because of an interesting observation some one made.
An archaeologist had found a phytolith "embedded" in the silica surface of a
stone tool. If this was embedded in the surface as a result of the silica gel
effect during the tool's use (in this case as a tool for cutting cereal grains,
a sickle), it would be a very interesting way to find out exactly what people
were doing with the tool. (this is part of a very large research effort to
determine the uses to which stone tools were put).
An alternative explanation could exist for the phytolith. That is, it is not
really a phytolith, but part of a diatom, and is a componant of the
fossiliferous flint from which the stone tool was made! In any event,
determining whether or not the "silica gel effect" was real thus became an
important part of this overall research program.
Cheers,
GTL
– Greg Laden, Written 18-Sep-1994 @ 20:42:06
Using: Windows NavCIS PRO 1.25
>> You want a sample? Email address and I'll mail you a couple of low g
gravel but you can find it anywhere in a gravel bed. Pick some small pieces
from within the bed. Grab a bit of the sand also, some of the sand is rounded
and glass like but most resulted from shattered quartz sprays. <<
Harvard University
11 Divinity Avenue
Cambridge MA 02138
– Greg Laden, Written 09-Sep-1994 @ 10:43:58
Using: Windows NavCIS PRO 1.25
Greg
Ok Plan a
Give me couple days I am going to "cook up"<gg> some fresh samples and look
some over then send them to you.
It would be great is if We could conference some microscopes Images live.
I'll mail em.
Kamron
Kamron