Ask a Geologist

[thaumaturgy]

......

 

[Orogeny]

OK, a lot of these elongated quartz. I assume this image may sort of represent the textural relationship between the quartz and the ooids. Right?

Haha. Why would I have posted it if it didn't?

How do you know it is the quartz which "penetrated" the ooids, rather than the ooids which enclosed the quartz?

Are you serious? Could you please outline how you think ooids are formed? Could you then please explain to me how, based on this outline, the quartz could have been incorporated into the ooids?

Actually, you know what, don't even bother. The reason it certainly is NOT what you say it is is that the quartz crystal clearly affects two separate ooids. This would not be possible if the ooids 'enclosed the quartz'.

The interpretation by the green text should be wrong. I do not see any nuclei of this authigenic quartz.

See the grain in the red circle? Yeah. Matrix quartz. We know it's matrix quartz because it's surrounded by equant cement (the fact that we can observe this cement also means that the out-of-the-plane diameter of the matrix grain is larger than the diameter of overgrowth). We also know that the quartz overgrowth nucleated on this grain because the grain and the overgrowth are in optical continuity. I'll reiterate: I've seen dozens of samples of this rock (not to mention mapping this unit out over several kilometers), and you've seen one image less than a millimeter square.

Seriously Juve, you may have some basic geologic knowledge, but don't pretend you can hang with those of us who have earned our stripes. You can't.

I am trying to polish your interpretation, which can only be good to you. If you don't like it, then I will more than happy to stop (there is a long list to go). Be humble, kid.

No, keep going, it lets me know what NOT to include in my writeup.

By the way, if you don't have the information related to my previous questions, I suggest you to get them one way or another. They would be important for a good interpretation. You may even encounter those questions in your defense.

Didn't I mention that I have analyzed these samples for more than 40 characteristics AND gathered geochemical data on them? Don't you think I probably know about as much as could be known about these rocks? Do you really think that noting quartz content is a new and revolutionary idea?

 

[juvenissun]

Haha. Why would I have posted it if it didn't?

Are you serious? Could you please outline how you think ooids are formed? Could you then please explain to me how, based on this outline, the quartz could have been incorporated into the ooids?

Actually, you know what, don't even bother. The reason it certainly is NOT what you say it is is that the quartz crystal clearly affects two separate ooids. This would not be possible if the ooids 'enclosed the quartz'.

See the grain in the red circle? Yeah. Matrix quartz. We know it's matrix quartz because it's surrounded by equant cement (the fact that we can observe this cement also means that the out-of-the-plane diameter of the matrix grain is larger than the diameter of overgrowth). We also know that the quartz overgrowth nucleated on this grain because the grain and the overgrowth are in optical continuity. I'll reiterate: I've seen dozens of samples of this rock (not to mention mapping this unit out over several kilometers), and you've seen one image less than a millimeter square.

Seriously Juve, you may have some basic geologic knowledge, but don't pretend you can hang with those of us who have earned our stripes. You can't.


No, keep going, it lets me know what NOT to include in my writeup.
Didn't I mention that I have analyzed these samples for more than 40 characteristics AND gathered geochemical data on them? Don't you think I probably know about as much as could be known about these rocks? Do you really think that noting quartz content is a new and revolutionary idea?

The circled quartz is definitely the remnant of the corroded (or replaced) quartz. You have only ONE quartz crystal in this image. You may confirm this interpretation by examining other thin sections. I bet most quartz grains embedded by the calcite matrix are of the same origin. (That is why I asked you if you see chert grains in the rock.)

Now, you may be able to figure out a lot more details related to the crystallization history of this rock.

Do you want me to continue?

 

[Orogeny]

The circled quartz is definitely the remnant of the corroded (or replaced) quartz.

First, you completely ignored my specific explanation of why this CANNOT be a single quartz crystal.

Second, in your 'expert' opinion, the following things happened:

1. a matrix quartz grain was incorporated in the rock
2. the grain was dissolved LEAVING THE SURROUNDING CARBONATE INTACT,
3. no further cementation took place in the new pore, then
4. a new quartz crystal nucleated SOMEWHERE NEAR THE PORE (after all, it couldn't have nucleated in the pore, otherwise we would see an isopachous rim of quartz crystals around the pore margin-we don't), then
5. the crystal grew into the pore, filling it completely with a single crystal.



Yeah, that's WAY SIMPLER than:
1. A matrix quartz grain was incorporated into the rock,
2. The grain developed a penetrative overgrowth.

How did I not think of that?

You have only ONE quartz crystal in this image. You may confirm this interpretation by examining other thin sections.

Oh man, you're killing me here Juve. As I have already stated, I've got DOZENS of thins of these rocks clearly showing that these are, in every case, overgrowths on detrital quartz grains. Read. It's not difficult.

I bet most quartz grains embedded by the calcite matrix are of the same origin. (That is why I asked you if you see chert grains in the rock.)

This doesn't even make sense. Authigenic quartz crystals are not grains! They are AUTHIGENIC CRYSTALS!

Now, you may be able to figure out a lot more details related to the crystallization history of this rock.

Picard so hard.

Do you want me to continue?

One thousand times over, yes, yes, yes! Continue! Derail my thread! For the lulz!

 

[3rdHeaven]

I don't know beans about quartz but in case your wondering how this looks from the out side looking in, Juve is looking and sounding 150% more professional. and your acting like a snotty know it all kid. No offense, but thought you might be interested to hear that. You may want to work on your delivery a bit. You may know more then Juve but by your posts I would never know that, just saying.

Peace

 

[Tiberius]

And that's how a used car salesman with a neat suit and nice haircut can sell you a car that runs like an asthmatic camel. Because he sells it. But you're still a fool if you don't take a test drive.

Likewise, when looking for the truth about the way the world works, don't just go with whoever presents their arguments in the snazziest way. Go out and do your own research into things and see for yourself who is right.

 

[razeontherock]

can sell you a car that runs like an asthmatic camel.

Snort. Chuckle. I have to remember that ...

 

[Orogeny]

I don't know beans about quartz but in case your wondering how this looks from the out side looking in, Juve is looking and sounding 150% more professional.and your acting like a snotty know it all kid. No offense, but thought you might be interested to hear that.

I'm not. I'm sorry you can't follow the conversation, but Juve is essentially telling me that he know more about the science I'm doing based on 5 minutes' study of a 1mm x 1mm photomicrograph than I do after dedicating thousands of hours investigating tens of square kilometers of the same system. You tell me who's being ridiculous here. Also realize that Juve holds himself up as an authority on geology even though he has demonstrated little to no grasp of the subject, and when pressed for evidence for his statements, responds with statements like those quoted by Thaumaturgy here.

You may want to work on your delivery a bit. You may know more then Juve but by your posts I would never know that, just saying.

If you're after delivery, you'll find some of the best at Answers in Genesis. If you're looking for scientific reliability, you'll look to scientists and not snake oil salesmen. I mean seriously. The guy invokes intersecting multidimensional timelines to explain the age of the earth.

Go back and read the thread again. You will see that my evidence backs my assertions.

If you've got a question regarding geoscience, I'd be happy to answer it.

 

[juvenissun]

First, you completely ignored my specific explanation of why this CANNOT be a single quartz crystal.

Second, in your 'expert' opinion, the following things happened:

1. a matrix quartz grain was incorporated in the rock
2. the grain was dissolved LEAVING THE SURROUNDING CARBONATE INTACT,
3. no further cementation took place in the new pore, then
4. a new quartz crystal nucleated SOMEWHERE NEAR THE PORE (after all, it couldn't have nucleated in the pore, otherwise we would see an isopachous rim of quartz crystals around the pore margin-we don't), then
5. the crystal grew into the pore, filling it completely with a single crystal.



Yeah, that's WAY SIMPLER than:
1. A matrix quartz grain was incorporated into the rock,
2. The grain developed a penetrative overgrowth.

How did I not think of that?

Oh man, you're killing me here Juve. As I have already stated, I've got DOZENS of thins of these rocks clearly showing that these are, in every case, overgrowths on detrital quartz grains. Read. It's not difficult.

This doesn't even make sense. Authigenic quartz crystals are not grains! They are AUTHIGENIC CRYSTALS!

Picard so hard.

One thousand times over, yes, yes, yes! Continue! Derail my thread! For the lulz!

So you said the quartz overgrowth in your limestone is commonly observed.

In spite of your bad attitude, I am interested in your rock. In particular, the quartz/ooids relationship is inspiring (it is my first time seeing that). It strongly suggest at least a shallow burial origin of the ooids. The the logic sequence would be:

detrital quartz (?) > dissolution of detrital quartz (?) > quartz authigenesis (euhedral quartz and overgrowth) > formation of ooids > corrosion of authigenic quartz > cementation of limestone.

There would still be a few minor problems in this model. But, any question so far?

Are you doing this for your MS or Ph.D.?

 

[Orogeny]

Based on your 'logic sequence', you've absolutely no idea how ooids form. Read this webpage, then revise your sequence.

 

[thaumaturgy]

I don't know beans about quartz but in case your wondering how this looks from the out side looking in, Juve is looking and sounding 150% more professional. and your acting like a snotty know it all kid. No offense, but thought you might be interested to hear that. You may want to work on your delivery a bit. You may know more then Juve but by your posts I would never know that, just saying.

Peace

3rd Heaven, let me put my two cents in. I have a BS, MS and PhD in geology. I've dealt with Juvenissun on numerous occasions before on geologic topics.

Juvenissun does appear to have some bit of geologic training, but I have to say, in my opinion, his actions, his posts and his points are seldom particularly "professional". The only thing he does is keep his condescension well moderated.

Don't get me wrong, it is still there, he talks big, but when pressed to support the geology will either back down, refuse to answer or turn the onus on those who are reading his "stuff" to figure it out.

He has a unique way of getting under my skin at least. I don't actually believe he is particularly advanced in his knowledge of geology, but that is not to say he has no training. I simply feel he is invested more in making it appear that he has some greater knowledge than he actually has.

Again, simply my two cents, speaking as one with significant training in geology and one who has himself taught geology at the university level as well (another area Juvenissun has indicated some skill but seldom shows it).

 

[thaumaturgy]

detrital quartz (?) > dissolution of detrital quartz (?) > quartz authigenesis (euhedral quartz and overgrowth)

So the quartz crystal forms somewhere, but the ooids were not yet formed? And this doesn't make the quartz allochthonous? Was the quartz crystal forming "authigenically" suspended in the void of space and the ooids later formed around it?

I thought the words "authigenic" and "allochtonous" had some meaning in geology. Was I mistaken?

> formation of ooids > corrosion of authigenic quartz > cementation of limestone.

So the authigenic quartz (which is actually in relation to the ooids allochthonous, not authigenic) is corroded?

There would still be a few minor problems in this model.

Just a few.

Are you doing this for your MS or Ph.D.?

Maybe it's just for a book report in junior high school geology class. You know, junior high school geology? Like when you cited a jr high geology class for your definition of "mountain" here?

I bet he's going to be doing some re-writes after reading your posts, Juvenissun.

Get to it, Orogeny!

 

[Jazer]

Juve is essentially telling me that he know more about the science I'm doing based on 5 minutes' study of a 1mm x 1mm photomicrograph than I do after dedicating thousands of hours investigating tens of square kilometers of the same system. You tell me who's being ridiculous here.

Isn't that what the Atheists do when they want to put 5 min study into the Bible and expect that they know more then people who have read the Bible many times and put many years of study in. Chances are they do not even read the Bible but just get mis informed by another atheist on a web site somewhere.

 

[Jazer]

I (or another geologist) will answer to the best of our ability.

Is there any conglomerate rock that is a result of continental plate technics. Or is conglomerate more the result of the ocean, and weather breaking the rock down.

 

[thaumaturgy]

Is there any conglomerate rock that is a result of continental plate technics. Or is conglomerate more the result of the ocean, and weather breaking the rock down.

The question here is somewhat vague and requires a rather detailed answer which may not particularly satisfy.

Conglomerates are merely a type of rock. It describes the features of the rock not the origin, but the features give some information about the origins.

In a conglomerates are simply rocks made up of a wide variety of particle sizes, mostly rounded grains that are cemented together by a finer grain matrix.

HEre's a nice picture of a conglomerate:

The rounding of the grains tells us something about the origin of the rock or at least the origin of the individual clasts in the rock. The rounding comes from being rolled around and eroded perhaps in a stream. If the individual clasts (chunks) are harder rocks like quartz-containing rocks it may take a lot of effort to smooth and round them.

Finally the chunks wound up somewhere that allowed them to be cemented together. This could have been in a basin formed due to plate tectonic actions, or it could have just been in lake fed by some relatively strong streams which could carry these things down there.

Counter this with something called a Breccia.

Note that the clasts are much more angular and jagged. They haven't been eroded enough to become rounded. Sometimes breccias form in places like faults where the rock is shattered or broken up, sometimes breccias form because the clasts didn't have enough of a chance to be rounded.

So you can't really look at a conglomerate (or a breccia) and say "Oh that's due to plate tectonics".

 

[Orogeny]

Isn't that what the Atheists do when they want to put 5 min study into the Bible and expect that they know more then people who have read the Bible many times and put many years of study in. Chances are they do not even read the Bible but just get mis informed by another atheist on a web site somewhere.

If people would stop bringing bible discussions into the physical and life sciences board, this issue would resolve itself. But this is off topic, so let's move away from it.

 

[keith99]

Isn't that what the Atheists do when they want to put 5 min study into the Bible and expect that they know more then people who have read the Bible many times and put many years of study in. Chances are they do not even read the Bible but just get mis informed by another atheist on a web site somewhere.

Typically athiests are more apt to have read the Bible than Christians. That is read the whole thing cover to cover as opposed to chunks, likely taken out of context.

 

[RickG]

If people would stop bringing bible discussions into the physical and life sciences board, this issue would resolve itself. But this is off topic, so let's move away from it.

 

[Orogeny]

And that's how a used car salesman with a neat suit and nice haircut can sell you a car that runs like an asthmatic camel.

I dunno what and asthmatic camel runs like, but you reminded me of this clip and I laughed and laughed.

Girl vs. Camel (in race!) - YouTube

 

[Jazer]

If people would stop bringing bible discussions into the physical and life sciences board, this issue would resolve itself. But this is off topic, so let's move away from it.

So the Holocene Extinction and the Neolithic Revolution has nothing to do with Science?

Can you count the grains of sand?

17How precious to me are your thoughts, O God!
How vast is the sum of them!
18Were I to count them,
they would outnumber the grains of sand.
When I awake,
I am still with you.
Psalm 139 niv