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Author Topic:   Limestone Layers and the Flood
jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004


Message 106 of 128 (299478)
03-29-2006 8:43 PM
Reply to: Message 105 by Percy
03-29-2006 8:34 PM


One small question.
I was under the assumption that most limestone was originally made of the bodies of diatoms and other similar sized critters. IIRC they are really, really small critters, but often the limestone layers are hundreds to thousands of feet thick. Is that correct?


Aslan is not a Tame Lion
This message is a reply to:
 Message 105 by Percy, posted 03-29-2006 8:34 PM Percy has responded

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edge
Member
Posts: 4451
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.1


Message 107 of 128 (299503)
03-29-2006 10:46 PM
Reply to: Message 104 by Christian
03-29-2006 7:34 PM


Not that I understand chemical principles very well, but which chemical principles might it violate?

Okay, how do large bodies of water, at a specific gravity of 1 become emplaced in an oceanic crust with an SG of about 4. How do the caverns form, and where does the water come from? Does this water somehow dissolve gabbro?

In his book he goes into many evidences for the subterranian chamber. One of which is the mid-oceanic ridge.

So all mid-ocean ridges have caverns in them? WHat is the evidence for this? If you are going to be skeptical, these are the kinds of questions you need to start asking.


This message is a reply to:
 Message 104 by Christian, posted 03-29-2006 7:34 PM Christian has not yet responded

  
edge
Member
Posts: 4451
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.1


Message 108 of 128 (299504)
03-29-2006 10:50 PM
Reply to: Message 102 by Christian
03-29-2006 7:16 PM


Re: Do some of your comments help advance the discussion
I think I was referring to the binding, not the content. I don't understand the content well enough yet, to have formed an opinion.

Then I am confused. Didn't you write this:

"I know it's good quality because I purchased it about 3 years ago, and my husband and I have both read it and refered back to it many times and it has held up very well. That seems like a pretty good deal to me."

Perhaps interesting but not really a key point. Remember, all Christian had to judge by was the book itself. Let's see if we can stick to discussing content and individual evidences and not the medium

This message has been edited by AdminJar, 03-29-2006 09:59 PM


This message is a reply to:
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Replies to this message:
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arachnophilia
Member (Idle past 22 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 109 of 128 (299506)
03-29-2006 11:04 PM
Reply to: Message 108 by edge
03-29-2006 10:50 PM


Re: Do some of your comments help advance the discussion
and that quote started with "It costs $25 and you get a good quality hardback book. I know it's good quality because..."

let's not quotemine each other here. she says she didn't understand the content -- and opinions change as more information is acquired. she is asking for more information, so let's stick to that.


אָרַח

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 Message 108 by edge, posted 03-29-2006 10:50 PM edge has responded

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Percy
Member
Posts: 18249
From: New Hampshire
Joined: 12-23-2000
Member Rating: 4.0


Message 110 of 128 (299560)
03-30-2006 8:50 AM
Reply to: Message 106 by jar
03-29-2006 8:43 PM


Re: One small question.
jar writes:

I was under the assumption that most limestone was originally made of the bodies of diatoms and other similar sized critters. IIRC they are really, really small critters, but often the limestone layers are hundreds to thousands of feet thick. Is that correct?

Edge or Rox are probably better suited to answering this question, but my understanding is that sedimentary limestone layers are formed from a combination of the following:

  1. The skeletal remains of microscopic creatures known collectively as coccoliths, a type of algae.

  2. The same remains but after having passed through the digestive systems of other creatures such as coral or some fish.

  3. In some waters the concentration of calcium carbonate in the sea water is high enough to precipitate directly out of solution onto the seafloor. This is much more common in groundwater environments such as caves, but it apparently can happen in the ocean, too.

The composition of limestone layers ranges from almost exlusively type 1 to almost exclusively type 3. It is part of the reason why limestone building materials are available in such a wide variety of colors, textures and hardnesses. The range of temperatures and pressures and time a layer has been subjected to also have a considerable influence. Limestone under great pressure that is heated beyond a certain point becomes marble, which almost always erases all fossil evidence.

This thread is attempting to address the issue of how a flood could produce hundreds of feet of limestone layers in a single year, which at the rates we observe today would take well over a million years.

--Percy


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 Message 106 by jar, posted 03-29-2006 8:43 PM jar has not yet responded

Replies to this message:
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roxrkool
Member (Idle past 941 days)
Posts: 1493
From: Nevada
Joined: 03-23-2003


Message 111 of 128 (299561)
03-30-2006 9:12 AM
Reply to: Message 110 by Percy
03-30-2006 8:50 AM


Re: One small question.
In some waters the concentration of calcium carbonate in the sea water is high enough to precipitate directly out of solution onto the seafloor. This is much more common in groundwater environments such as caves, but it apparently can happen in the ocean, too.

Micrite is a significant component of carbonates, but it's origin is debated.

quote:
Origin of Micrite = Lime Mud

Micrite is lime mud. It exists in modern environments as extremely small aragonite crystals (needles) that can only be seen clearly with a scanning electron microscope. If you were to see the sediment, however, it would have the consistency of mud.

Aragonite is a variety of CaCO3 and is a common component of pearls and some shells. Aragonite is less stable than calcite, however, and more or less quickly recrystallizes to calcite.

The orgin of micrite has a long history of debate. Originally it was thought to be exclusively of chemical origin, precipitating directly out of supersaturated sea water. During the 1970's and 1980's evidence and opinion steadily shifted all the way to a biochemical origin for micrite - the sediment coming from the breakdown of calcareous algae skeletons which live abundantly in modern carbonate environments.

More recent evidence is pointing back to some micrite being of chemical origin. This is one of those problems that is yet to have a definitive solution. Micrite, though, is probably a mixture of chemical and biochemical origin.

By the time we see the rock, however, the aragonite/calcite needles have been so recrystallized and cemented that the original nature has been destroyed. Thus, the question of micrite origin is the focus of study of recent carbonates.

Source: Origin of micrite


This message has been edited by roxrkool, 03-30-2006 09:13 AM


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Replies to this message:
 Message 116 by Christian, posted 03-30-2006 5:25 PM roxrkool has responded

    
Christian
Member (Idle past 4300 days)
Posts: 157
Joined: 10-16-2005


Message 112 of 128 (299622)
03-30-2006 4:09 PM
Reply to: Message 105 by Percy
03-29-2006 8:34 PM


Re: Request that we address the topic
Percy,
You are the one that started this topic, so I want to respect your wishes to assume that the limestone is organic in nature. And again I am very ignorant in this field, so perhaps I'm misunderstanding something, but doesn't Message 111indicate that there is some debate about the origen of limestone (micrite in particular)?
This message is a reply to:
 Message 105 by Percy, posted 03-29-2006 8:34 PM Percy has responded

Replies to this message:
 Message 113 by Percy, posted 03-30-2006 4:43 PM Christian has responded

    
Percy
Member
Posts: 18249
From: New Hampshire
Joined: 12-23-2000
Member Rating: 4.0


Message 113 of 128 (299629)
03-30-2006 4:43 PM
Reply to: Message 112 by Christian
03-30-2006 4:09 PM


Re: Request that we address the topic
Christian writes:

And again I am very ignorant in this field, so perhaps I'm misunderstanding something, but doesn't Message 111indicate that there is some debate about the origen of limestone (micrite in particular)?

Debate? Between professional geologists? No, there is no debate.

The short answer is that you're being flim-flammed into thinking there's any scientific doubt on the matter. If you want a longer answer I think you should propose your own thread.

You keep alluding to your ignorance, but I don't think that's really a problem because ignorance is easily remedied. The real problem is that you don't know who to believe. Your inclination is to believe those telling you things consistent with your beliefs. You're also inclined to give credence to professional scientists.

Are you a professional or is there something you're really good at, perhaps a craft or a sport? Let me pick the medical profession, since everyone's been to the doctor. Let's say you're a doctor specializing in backs. You show a patient their X-Ray of a herniated disk with a fragment pressing dangerously against the spinal column. You tell them they're in danger of eventual paralysis without surgery. The patient isn't so sure. He's heard stories that plenty of people do fine without surgery. His chiropractor has told him that weekly manipulation is all he needs. He's read advertisements for magnets that he can wear that will fix his disk. A friend had wonderful results from sleeping next to a model pyramid. A neighbor down the street with a back problem saw a faith healer and now plays rugby. Doesn't all this imply that there is some debate about whether surgery is necessary?

The relevant question: Debate between whom? Between doctors in your profession? No, of course not. The patient is paying the most attention to the message he wants to hear, that he's not really in any danger and that he'll be alright without painful surgury.

And that's your real problem, not ignorance. Your rational side knows that the professionals who make a career in science are much more likely to be right, but they're not telling you the message you want to here. Walt Brown has made a career not out of science, but out of selling books and other materials to support a ministry, but he's got the right message as far as you're concerned.

--Percy

This message has been edited by Percy, 03-30-2006 04:44 PM


This message is a reply to:
 Message 112 by Christian, posted 03-30-2006 4:09 PM Christian has responded

Replies to this message:
 Message 114 by Minnemooseus, posted 03-30-2006 5:05 PM Percy has responded
 Message 117 by Christian, posted 03-30-2006 5:41 PM Percy has not yet responded

    
Minnemooseus
Member
Posts: 3696
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001


Message 114 of 128 (299634)
03-30-2006 5:05 PM
Reply to: Message 113 by Percy
03-30-2006 4:43 PM


There are always details to be debated
Debate? Between professional geologists? No, there is no debate.

The short answer is that you're being flim-flammed into thinking there's any scientific doubt on the matter.

The above quoted goes a bit too far. While, as best I know, there is indeed broad agreement that the majority of limestones are of direct or indirect biological origin, there are always details and specific occurances to be debated.

Also, I think there's sometimes a strong tendancy for geologists and other scientists to go "devils advocate". Question and debate conclusions even though you actually do agree with the conclusions. Maybe it's just a professional version of "everyone loves a good argument".

I find it mighty surprising that you would make a statement such as the above.

Moose


This message is a reply to:
 Message 113 by Percy, posted 03-30-2006 4:43 PM Percy has responded

Replies to this message:
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Percy
Member
Posts: 18249
From: New Hampshire
Joined: 12-23-2000
Member Rating: 4.0


Message 115 of 128 (299635)
03-30-2006 5:20 PM
Reply to: Message 114 by Minnemooseus
03-30-2006 5:05 PM


Re: There are always details to be debated
Moose writes:

I find it mighty surprising that you would make a statement such as the above.

Hey, I'm just full of surprises today! :D

Was the context more ambiguous than I thought? The point I thought I was making was the very same one you made, that "there is indeed broad agreement that the majority of limestones are of direct or indirect biological origin." Unless there are geologists out there somewhere seriously arguing for a significant non-organic origin, there's no debate about this. I didn't mean to imply there's no debate about any limestone anywhere.

--Percy


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Christian
Member (Idle past 4300 days)
Posts: 157
Joined: 10-16-2005


Message 116 of 128 (299636)
03-30-2006 5:25 PM
Reply to: Message 111 by roxrkool
03-30-2006 9:12 AM


Re: One small question.
roxrkool writes:

The orgin of micrite has a long history of debate. Originally it was thought to be exclusively of chemical origin, precipitating directly out of supersaturated sea water. During the 1970's and 1980's evidence and opinion steadily shifted all the way to a biochemical origin for micrite - the sediment coming from the breakdown of calcareous algae skeletons which live abundantly in modern carbonate environments.

More recent evidence is pointing back to some micrite being of chemical origin. This is one of those problems that is yet to have a definitive solution. Micrite, though, is probably a mixture of chemical and biochemical origin.


This looks like you're saying there is debate among scientists as to the origen of limestone. Is that what you're saying, or am I misunderstanding you because of my ignorance? If I am misunderstanding, then could you please explain to me what you are saying?
This message is a reply to:
 Message 111 by roxrkool, posted 03-30-2006 9:12 AM roxrkool has responded

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Christian
Member (Idle past 4300 days)
Posts: 157
Joined: 10-16-2005


Message 117 of 128 (299642)
03-30-2006 5:41 PM
Reply to: Message 113 by Percy
03-30-2006 4:43 PM


Re: Request that we address the topic
I was going to quit for the day, but I couldn't resist this one.

Percy writes:

The short answer is that you're being flim-flammed into thinking there's any scientific doubt on the matter. If you want a longer answer I think you should propose your own thread.

I just might do that, and I don't intend to use much more space on your thread, but need to answer this.

Percy writes:

You keep alluding to your ignorance, but I don't think that's really a problem because ignorance is easily remedied. The real problem is that you don't know who to believe. Your inclination is to believe those telling you things consistent with your beliefs. You're also inclined to give credence to professional scientists.


The reason I was alluding to my ignorance was because the way I read roxrkool's post, it looked like she was saying that there was a debate. I thought that there was no debate among "professional scientists". So I thought maybe I was misunderstanding because of my ignorance.

Percy writes:

Are you a professional or is there something you're really good at, perhaps a craft or a sport?


I think I'm pretty good at raising kids. But there is a lot of debate among us professional kid-raisers as to the best methods, so I'm not sure that's a good one.

Percy writes:

Let me pick the medical profession, since everyone's been to the doctor.


Probably not a good one either, since I tend to distrust physicians, mainly because they make their money off of drugs and surgery. I think both are often not as necessary as they make it seem. I usually throw away prescriptions without filling them.
This message is a reply to:
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roxrkool
Member (Idle past 941 days)
Posts: 1493
From: Nevada
Joined: 03-23-2003


Message 118 of 128 (299657)
03-30-2006 7:03 PM
Reply to: Message 116 by Christian
03-30-2006 5:25 PM


Re: One small question.
Actually, I did not personally make that statement, it was quoted from the link provided.

I'm not a carbonate geologist, but it is my understanding that while there used to be a lot of debate as the the origin of micrite, these days, most carbonate geologists seem to agree that micrite is primarily composed of the altered remains of aragonitic algal skeletons.

This is likely due to the amount of sampling and coring of modern oceanic sediment, which show appreciable amounts of aragonitic needles. These needles later alter to calcite, which is a more stable form of CaCO3, to form the limy mud called micrite.

However, no one can yet deny that supersaturation results in some carbonate precipitation in marine settings, but from what I've read, carbonate geologists don't believe supersaturation can contribute as much micritic carbonate as that derived from algal skeletons.

I found one paper from 1999 written by a microbiogeologist, but I can hardly understand the thing. It does state the following at the end, however:

Thus, apart from (probably mythical) purely evaporitic and autotrophic ones, most limestones must be considered as principally of heterotrophic bacterial origin. As the carbon of limestones is issued from organic matter, bacterial heterotrophic carbonatogenesis appears as a fundamental phenomenon in the relationships between atmosphere and lithosphere during the biogeological evolution of the Earth.

SOURCE: Camoin, Gilbert F, 1999, Ca-carbonates precipitation and limestone genesis; the microbiogeologist point of view, in Special issue: Microbial mediation in carbonate diagenesis,Sedimentary Geology, vol.126, no.1-4, pp.9-23.

I THINK it's saying most limestone is biogenically-derived, but I could be wrong, I had a hard time following the bio stuff.

Here is the whole thing for those more knowledgeable of the terminology - maybe they can interpret:

Abstract

Experiments show that the production of carbonate particles by heterotrophic bacteria follows different ways. In heterotrophy, the passive carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. It is induced by several metabolic pathways of the nitrogen cycle (ammonification of amino-acids, degradation of urea and uric acid, dissimilatory reduction of nitrates) and of the sulphur cycle (dissimilatory reduction of sulphates). The active carbonatogenesis is independent of the mentioned metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. In autotrophy, non-methylotrophic methanogenesis and cyanobacterial photosynthesis also may contribute to the precipitation of carbonates (autotrophic carbonates). As carbonatogenesis is neither restricted to particular taxonomic groups of bacteria nor to specific environments, it has been an ubiquitous phenomenon since Precambrian times. Carbonatogenesis is the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. After a phase of latency, there is an exponential increase of bacterial numbers together with the accumulation of metabolic end-products. These induce a pH increase and an accumulation of carbonate and hydrogenocarbonate ions in the medium. This phase ends into a steady state when most part of the initial enrichment is consumed and there is a balance between death and growth in bacterial populations. Particulate carbonatogenesis occurs during the exponential phase and ends more or less after the beginning of the steady state. The active carbonatogenesis seems to start first and to be followed by the passive one which induces the growth of initially produced particles. In eutrophic conditions, the first solid products are patches that appear on the surface of the bacterial bodies and coalesce until forming a rigid coating and/or particles excreted from the cell. All these tiny particles assemble into biomineral aggregates which often display "precrystalline" structures. These aggregates grow and form biocrystalline build-ups which progressively display more crystalline structures with growth. In oligotrophic conditions, the primary solid products are rapidly smoothed in the crystalline structure and leave no trace. In present aqueous environments, apart from deep ocean, the potential efficiency of heterotrophic bacterial carbonatogenesis in Ca-carbonate sedimentation is much higher than autotrophic or abiotic processes. It much more likely accounts for extensive apparently abiotic limestone formation than any of the latter. As far as biodetrital particles are concerned, it may be observed that the shells and tests of organisms are built from the activity of cellular organites which are nowadays considered by a number of biologists as endosymbiotic bacteria. Thus, apart from (probably mythical) purely evaporitic and autotrophic ones, most limestones must be considered as principally of heterotrophic bacterial origin. As the carbon of limestones is issued from organic matter, bacterial heterotrophic carbonatogenesis appears as a fundamental phenomenon in the relationships between atmosphere and lithosphere during the biogeological evolution of the Earth.


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Percy
Member
Posts: 18249
From: New Hampshire
Joined: 12-23-2000
Member Rating: 4.0


Message 119 of 128 (299700)
03-30-2006 9:17 PM
Reply to: Message 118 by roxrkool
03-30-2006 7:03 PM


Re: One small question.
roxrkool writes:

I THINK it's saying most limestone is biogenically-derived, but I could be wrong, I had a hard time following the bio stuff.

I can't see any other possible conclusion, and he really emphasizes this point with the "probably mythical" parenthesized comment in reference to purely non-biogenic limestone.

If inorganic sedimentary limestone deposits collected in any significant amounts on sea floors in areas with no significant presence of "heterotrophic bacteria" then we would already know about it. All the articles about limestone layers say they formed in warm shallow seas not because geologists just made it up so they could go home early, but because that is where they've observed limestone layers forming today. And I assume they find that cold, deep seas produce much less in the way of limestone deposits.

The more closely you investigate anything the more you find that the picture is more complicated than you thought, but as long as the big picture is informed by the lower level detail that picture will be correct. Simplified, of course, but correct. This is the process of popularization in science. I assume the writers of the popularizations are rendering pictures consistent with lower level details. I assume if such popularizations were largely wrong that geologists would let us know about it. I assume when I read these popularizations that I'm learning a simplified view, not a wrong view that happens to be simple enough for laypeople.

You can point to a picture of a green tablecloth on a page of a magazine and say, "This is green," and then someone can put it under a microscope and say, "Aha! There are dots of red mixed in." And so there are, but that doesn't mean the tablecloth isn't green.

Christian is making the mistake of looking through the microscope before she understands the big picture, and every time the equivalent of one of those dots of red comes into view she thinks she's found something that just doesn't add up. She doesn't realize that the detailed picture is always messy and complicated and confusing. That's why you have to go to college for 8 years to even begin to understand this stuff. That's why they teach 1st grade science in 1st grade and 12th grade science in 12th grade and not the other way around.

Christian will focus her magnifying glass here and there in no particularly connected order and be given little-understood explanations and never fit it all together. And I think Walt Brown, maybe not consciously, knows that his work has this effect. He knows it isn't necessary to convince, only to confuse. I think he's pretty good at what he does.

--Percy


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edge
Member
Posts: 4451
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.1


Message 120 of 128 (299703)
03-30-2006 9:55 PM
Reply to: Message 108 by edge
03-29-2006 10:50 PM


Re: Do some of your comments help advance the discussion
Perhaps interesting but not really a key point. Remember, all Christian had to judge by was the book itself. Let's see if we can stick to discussing content and individual evidences and not the medium

Then it shouldn't have been brought up in the first place.


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 Message 108 by edge, posted 03-29-2006 10:50 PM edge has not yet responded

  
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