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Author | Topic: Chalk takes millions of years to form | |||||||||||||||||||||||||||||||||||||||||||||||||||
Tangle Member Posts: 9509 From: UK Joined: Member Rating: 4.8
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If you were new here and didn't know any better you could be forgiven for thinking that all of the earth's geology is contained in the Grand Canyon.
This is the geology of my home town on the south coast of England:
The White Cliffs of Dover - and those of my home town - are chalk. Chalk, according to wiki is:
The cliffs are composed mainly of soft, white chalk with a very fine-grained texture, composed primarily of coccoliths, plates of calcium carbonate formed by coccolithophores, single-celled planktonic algae whose skeletal remains sank to the bottom of the ocean during the Cretaceous and, together with the remains of bottom-living creatures, formed sediments. Flint and quartz are also found in the chalk Chalk is useful stuff, you can cut the turf and make naughty pictures:
2. Cerne Abbas Giant — 180 ft tall Also known as the Rude Man, the Cerne Abbas Giant in Dorset is carved into the side of a steep hill and formed by a 12-inch wide trench. The Giant with an erect penis wields a 120-ft knobbled club, and probably formerly held a cloak or animal skin in its left arm while standing over a disembodied head. But chalk is also very old. My lot - and apparently most of the world's chalk - was formed in the late cretaceous period (66-100mya). The chalk beds around here are about 400m deep and the highest is about 110m above sea level. It takes about 1,000 years to build 1-10 cm of chalk (depending on type and condition). So if we started today, and use the fastest rate, it would take 4 million years to build my chalk cliffs. I'm no geologist, but it seems to me that this single piece of geology is enough to prove that the earth is older than 6,000 years. Anyone care to put me right? Edited by Tangle, : No reason given. Edited by Tangle, : No reason given.Life, don't talk to me about life - Marvin the Paranoid Android
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AdminNosy Administrator Posts: 4754 From: Vancouver, BC, Canada Joined: |
Thread copied here from the Chalk takes millions of years to form thread in the Proposed New Topics forum.
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Stile Member Posts: 4295 From: Ontario, Canada Joined: |
Tangle writes: Anyone care to put me right? No. But I do have a chalk-question, and you are now the appointed chalk-expert. So here it is: This geological chalk you're talking about. Is it the same as colloquial chalk? Like the stuff used by teachers in classrooms on chalkboards?If so, is there any "chalk shortage" coming about from all the teachers using it up... what with it taking so long to make more, anyway. Just wondering.
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Tangle Member Posts: 9509 From: UK Joined: Member Rating: 4.8 |
Stile writes: This geological chalk you're talking about. Is it the same as colloquial chalk? Like the stuff used by teachers in classrooms on chalkboards? I reckon they would have been originally - the kids here take great fallen chunks of it and scrawl everywhere, of course - but apparently now they're : " often made not from chalk rock but from calcium sulfate in its dihydrate form, gypsum. Chalk sticks containing calcium carbonate typically contain 40-60% of CaCO3"
If so, is there any "chalk shortage" coming about from all the teachers using it up... what with it taking so long to make more, anyway. Nope. And anyway, pretty much all schools now use whiteboards with marker pens. Pity really, I suspect having a teacher throw a marker pen at you will cause more damage than chalk.Life, don't talk to me about life - Marvin the Paranoid Android
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ringo Member (Idle past 437 days) Posts: 20940 From: frozen wasteland Joined: |
Tangle writes:
As I understand it, the reason it takes so long is because the smaller the particle size, the longer it takes to settle to the bottom (Stokes' Law). Since we know the particle size today, we can calculate the time. It takes about 1,000 years to build 1-10 cm of chalk (depending on type and condition). So if we started today, and use the fastest rate, it would take 4 million years to build my chalk cliffs. If somebody can elaborate on this, it might help to short-circuit any claims that, "it happened in the past so we can't possibly know anything about it."
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Dr Adequate Member (Idle past 309 days) Posts: 16113 Joined: |
Well, not really. It takes a few decades to get to the ocean floor. The reason accumulation is so slow is that coccolithophores aren't very big and there aren't that many of them. Nor could there be, since they photosynthesize and so need to be near the surface and not overshadowed by loads of other coccolithophores.
Historical Geology/Calcareous ooze - Wikibooks, open books for an open world Edited by Dr Adequate, : No reason given. Edited by Dr Adequate, : No reason given.
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New Cat's Eye Inactive Member
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Chalk takes millions of years to form If chalk is calcium carbonate, and calcium carbonate is hard water scale, then the fact that I can get hard water scale on my showerhead in the order of weeks seems to suggest that it does not take millions of years for chalk to form.
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Faith  Suspended Member (Idle past 1469 days) Posts: 35298 From: Nevada, USA Joined: |
A Floodist like me would hypothesize that the cliffs were like any of the thick strata anywhere on the earth, the result of the transportation by water of already-formed already-existent particles to their current location, and that before the Flood conditions were such that it didn't take so long for them to accumulate anyway. Any reason why this isn't possible?
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Dr Adequate Member (Idle past 309 days) Posts: 16113 Joined: |
A Floodist like me would hypothesize that the cliffs were like any of the thick strata anywhere on the earth, the result of the transportation by water of already-formed already-existent particles to their current location, and that before the Flood conditions were such that it didn't take so long for them to accumulate anyway. Any reason why this isn't possible? So millions of years' worth of calcareous ooze formed in the two thousand years before the Flood? Edited by Dr Adequate, : No reason given.
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Dr Adequate Member (Idle past 309 days) Posts: 16113 Joined:
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No. But I do have a chalk-question, and you are now the appointed chalk-expert. So here it is: This geological chalk you're talking about. Is it the same as colloquial chalk? Like the stuff used by teachers in classrooms on chalkboards?If so, is there any "chalk shortage" coming about from all the teachers using it up... what with it taking so long to make more, anyway. Just wondering.
Blackboard chalk, French chalk, billiard chalk, tailors' chalk and the chalk used by weightlifters are not chalk. It's like the Great Granite Swindle all over again. Edited by Dr Adequate, : No reason given.
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Dr Adequate Member (Idle past 309 days) Posts: 16113 Joined: |
If chalk is calcium carbonate, and calcium carbonate is hard water scale, then the fact that I can get hard water scale on my showerhead in the order of weeks seems to suggest that it does not take millions of years for chalk to form. Chalk isn't just any old calcium carbonate, it's calcium carbonate made out of coccoliths.
IIRC, this was first discovered by Thomas Henry Huxley ("Darwin's Bulldog").
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New Cat's Eye Inactive Member
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Ah, okay. That makes sense. You couldn't write on a chalkboard with a hunk of hard water scale from your showerhead like you can with a piece of chalk.
Given that coccoliths are individual plates of calcium carbonate:
You can envision how the plates would slide off each other and leave behind that nice sheet of chalk that makes it such a good writing utensil. ABE: So yeah, given this:
Holy shit that a whole lotta Coccolithophores (single celled algae)! Yeah, that's gonna take a while... Edited by Catholic Scientist, : No reason given.
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Tangle Member Posts: 9509 From: UK Joined: Member Rating: 4.8 |
Faith writes: A Floodist like me would hypothesize that the cliffs were like any of the thick strata anywhere on the earth, the result of the transportation by water of already-formed already-existent particles to their current location, and that before the Flood conditions were such that it didn't take so long for them to accumulate anyway. Any reason why this isn't possible? Well, as Dr a says, even supposing that was possible, you still have to have many millions of years before your flood to manufacture the plankton and have it die and sink to the bottom. But even if you had the coccoliths all there and ready before the flood, they had been geologically formed into ROCK, not dandruff, and wouldn't be going anywhere. (And btw, my cliffs are only 100 meters above sea level, but the chalk under the North sea is 1km thick.)Life, don't talk to me about life - Marvin the Paranoid Android
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Tangle Member Posts: 9509 From: UK Joined: Member Rating: 4.8 |
This is apparently the correct creationist response:
Can Flood geology explain thick chalk beds? - creation.comLife, don't talk to me about life - Marvin the Paranoid Android
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Dr Adequate Member (Idle past 309 days) Posts: 16113 Joined:
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There's no such thing as the creationist response to any given fact they need to explain away. We'll have to see what Faith has to say about it.
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