Jump to content

Limestone, Dolomite and Calcium deposites


Mike Smith Cosmos

Recommended Posts

When looking at Great White Cliffs, stacks or other limestone outcrops a question arises . What proportion of what one sees, comes about by precipitation from the ocean water without living intervention?

 

 

Is this origin purely chemical ( NOT of Plant or Animal origin ) Half, 10 % 75 % 2% or what ever ? Clearly a lot comes from living origin; Coral, Plankton , Algae and other calcite ooze or slime, but what proportion is from once NON living origin ?

 

Calcium as an element must have come from an exploding star at some stage. Did it go molecular while still in space , or was there some form of processing in the earth mantle or core ?

 

I believe this has a relevance to A) Production /Reduction of Oxygen in deep history and B) Increase/Decrease of Carbon today

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

If you mean things like this

 

http://en.wikipedia.org/wiki/White_Cliffs_of_Dover

 

then all of it is biological

 

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.

 

And writing like this makes it hard to read.

Link to comment
Share on other sites

all of it is biological

 

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.

 

 

 

I had the feeling this was the answer.

 

But I still struggle a bit with where do the critters get the Calcium Carbonate or calcite from in the first place.

 

It must be in the ocean, I would suspect in a dissolved form or particle form. So the calcium must be in solution or in some form in the water. So where did that come from?

 

 

If we say from past sediment, well, that must at some stage have come from somewhere. Where ? And in what form ?

 

.

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

Calcium is a common element in feldspars, pyroxenes, amphiboles and micas, all of which are very commonplace in igneous rocks. Calcite cement is common in clastic rocks. Many metamorphic rocks contain calcium rich minerals. Many clays are also calcium rich. There is a lot of it about and some of it goes into solution during the weathering and erosion process. I'm sure a quick google will give you concentrations in typical 'fresh water' and sea water.

Link to comment
Share on other sites

Calcium is a common element in feldspars, pyroxenes, amphiboles and micas, all of which are very commonplace in igneous rocks. Calcite cement is common in clastic rocks. Many metamorphic rocks contain calcium rich minerals. Many clays are also calcium rich. There is a lot of it about and some of it goes into solution during the weathering and erosion process. I'm sure a quick google will give you concentrations in typical 'fresh water' and sea water.

 

 

 

So what you are saying, which is what I thought must be the case is : That all the calcium to make all the clay, chalk , limestone, white cliffs of Dover and all the other cretaceous strata everywhere and any present in any limestone or otherwise calcium orientated rock , before going through the critter mode, must have been somewhere in the mantle all mixed up in the minerals you mentioned above. Is that so. ? So then it dissolved in the sea water or fresh water by erosion and got converted via the critters in the fullness of time to what we now see in the various strata. Is that about it. ?

 

.

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

Almost. The mantle does not need to be the source. Much of the material is recylced from the crust.

 

I am still trying to track down all this calcium. the nearest I've got, which may not be the case as it sounds all a bit vague.

 

Everything was mantle apart from the core at the falling together of matter to bring the earth about . The first crusts appeared as a sort of scum of the lighter elements. Namely the dense heavy elements like iron and gold and uranium sunk to the center and lighter elements like silicon, aluminium , manganese, carbon bubbled to the top. These latter ones became the scum on top which became the first continental plates as well as ocean plates. As far as I can make out the ocean plates were , or included heavier minerals and thus the lighter scum became the continental plates. As the ocean plates subducted under the lighter continental plates a certain amount of scrapings rose up onto and became combined with the continental plates.

 

Quite what the journey of the calcium bearing minerals was before they got into the critter cycle I am still not quite sure.

Maybe in the scrapings. Maybe in the water. Maybe in the magma. Before the calcium could enter the critter cycles, the masses of calcium or minerals including calcium must have existed somewhere. But where ?

Link to comment
Share on other sites

  • 2 weeks later...

I am still trying to track down all this calcium. the nearest I've got, which may not be the case as it sounds all a bit vague.

 

Everything was mantle apart from the core at the falling together of matter to bring the earth about . The first crusts appeared as a sort of scum of the lighter elements. Namely the dense heavy elements like iron and gold and uranium sunk to the center and lighter elements like silicon, aluminium , manganese, carbon bubbled to the top. These latter ones became the scum on top which became the first continental plates as well as ocean plates. As far as I can make out the ocean plates were , or included heavier minerals and thus the lighter scum became the continental plates. As the ocean plates subducted under the lighter continental plates a certain amount of scrapings rose up onto and became combined with the continental plates.

 

Quite what the journey of the calcium bearing minerals was before they got into the critter cycle I am still not quite sure.

Maybe in the scrapings. Maybe in the water. Maybe in the magma. Before the calcium could enter the critter cycles, the masses of calcium or minerals including calcium must have existed somewhere. But where ?

 

Originally, you have a molten magmatic earth. However, the white cliffs of dover didnt form for another ~4.3 billions years later or so (pardon my quick math). The ocean plates are mafic and are made of denser materials than the felsic crustal surfaces. Calcium exists in many places, as previously mentioned by other people. It is very common in igneous minerals. So what you have is, the earth forms from igneous minerals, deposited. Billions of years later, calcium is dissolved into the oceans that eventually had formed. Then even further along, you have your microscopic sea critters absorbing it and making calcium deposits.

 

Calcium would be present in "scrapings", water and igneous minerals. How the organisms extract it from their environment is more of a question for biologists. Or earth scientists who happen to be well rounded with the biology of molluscs, or something along those lines.

 

Your questions relate to the origins of biological evolution, when, why and how paleo sea critters began to utilize calcium deposits from their environment.

 

I am not too familiar with this development, but it has always been my general impression that they absorb calcium that has dissolved into the oceans, or consume it when they consume other organisms (such as plants and other arthropods n such).

Edited by iDevonian
Link to comment
Share on other sites

Originally, you have a molten magmatic earth. However, the white cliffs of dover didnt form for another ~4.3 billions years later or so (pardon my quick math). The ocean plates are mafic and are made of denser materials than the felsic crustal surfaces. Calcium exists in many places, as previously mentioned by other people. It is very common in igneous minerals. So what you have is, the earth forms from igneous minerals, deposited. Billions of years later, calcium is dissolved into the oceans that eventually had formed. Then even further along, you have your microscopic sea critters absorbing it and making calcium deposits.

 

Calcium would be present in "scrapings", water and igneous minerals. How the organisms extract it from their environment is more of a question for biologists. Or earth scientists who happen to be well rounded with the biology of molluscs, or something along those lines.

 

Your questions relate to the origins of biological evolution, when, why and how paleo sea critters began to utilize calcium deposits from their environment.

 

I am not too familiar with this development, but it has always been my general impression that they absorb calcium that has dissolved into the oceans, or consume it when they consume other organisms (such as plants and other arthropods n such).

 

.

In connection with your delightful comments together with the extract provide by Ophiolite and John Cuthber, I have now built up an image that I have committed to an artists impression.

 

As I look at it now in front of me, I gaze across a few thousand miles of seething mantle, almost like a world full of Deckan Steps lava flow. There are some highpoints as subducting recent crust chunks are dragged down with the general convecting mantle. Some is left on the surface as the infant continental crust starts to form from assorted chunks. The sky with little atmosphere as we know it is lit by the neighboring sun. The atmosphere has a hue from several colours as it catches various elemental contents merging into the blackness of space.

 

The vault is studded beyond belief with orbiting mini asteroids, much like the rings of saturn. Because of their near proximity to each other and the earth, frequent collisions have caused a sea of meteorites to be moving this way and that across the sky. There is a general descending of these meteorites in waves toward the surface, but not with the speed or burning trail of our current experience of such objects. The sky is white with them due to their Calcium compound content, almost like falling high speed snow. Their proximity to earth and the sparse atmosphere is responsible for less velocity than todays' meteorites. The surface of the mantle/crust is sprinkled with the condrules like salt, even though not individually visible due to their minute individual size.

 

So the dark brown, red and black pudding mixture, matrix, churns waiting for the next stepping stones up through the aeons ( UK) /eons ( USA) of Pre Cambrian and Phanerozoic time. But in its heart among the silicates are the sprinklings of chondrules containing compounds of CALCIUM ready to be later absorbed by bacterial/Algae/Plankton and utilised by other Cambrian onwards critters to create their own calcium based shells, backbones and crustaceans. Thus became the fossil trail of the whole Phanerozoic Aeon/Eon to the present day.

 

Some to die by the ton and become the White Cliffs of Dover.

 

.

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

.

................. There is a general descending of these meteorites in waves toward the surface, but not with the speed or burning trail of our current experience of such objects. The sky is white with them due to their Calcium compound content, almost like falling high speed snow. Their proximity to earth and the sparse atmosphere is responsible for less velocity than todays' meteorites. The surface of the mantle/crust is sprinkled with the condrules like salt, even though not individually visible due to their minute individual size.

 

So the dark brown, red and black pudding mixture, matrix, churns waiting for the next stepping stones up through the aeons ( UK) /eons ( USA) of Pre Cambrian and Phanerozoic time. But in its heart among the silicates are the sprinklings of chondrules containing compounds of CALCIUM ready to be later absorbed by bacterial/Algae/Plankton .............

 

Some to die by the ton and become the White Cliffs of Dover.

 

.

.

 

Epilogue.

 

Having now reflected on Ophiolites' extract and tried to digest Wickepedia and its complicated explanation of meteorites and their twin sister Chondrites which are unmodified by melting, version of meteorites; It would appear that the very old Calcium compound Chondrules along with their companion Aluminium counterpart can be found in light grey silicates as white spheres. So the substance falling to the early earth might have been more Grey and white, perhaps looking more like high speed falling grit or dirty snow. I am sure it tasted just as delightful to early forms of life.

 

.

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

Having now reflected on Ophiolites' extract and tried to digest Wickepedia and its complicated explanation of meteorites and their twin sister Chondrites which are unmodified by melting, version of meteorites; It would appear that the very old Calcium compound Chondrules along with their companion Aluminium counterpart can be found in light grey silicates as white spheres. So the substance falling to the early earth might have been more Grey and white, perhaps looking more like high speed falling grit or dirty snow. I am sure it tasted just as delightful to early forms of life.

Mike, I don't no where to begin. Your enthusiasm is a beautiful thing and I fear to damage it, but you are trying to absorb so much information that it is not surprising you are getting some things quite wrong. Here is a minor attempt at a minor suite of corrections.

 

Chondrites are meteorites. Do not separate them out from the class.

 

Chondrites and their components have undergone various degrees of melting, but they have not undergone wholesale melting and differentiation, as is the case with the achondrites, irons and stony irons. (To complicate matters further there is evidence that the parent body for some chondrites has undergone some melting.)

 

While you are correct that a significant proportion of the calcium in chondrites is present in the CAI's, calcium-aluminium rich inclusions, some is also found within the pyroxenes in the chondrules.

 

The Earth did form from chondrites, but not directly. The chondrites accreted to form larger objects - planetesimals - which through a combination of kinetic and radioactive heat melted and formed differentiated bodies with mantle and core. It was the amalgamation of many of these modified bodies which formed the Earth.

Link to comment
Share on other sites

Mike, I don't no where to begin. Your enthusiasm is a beautiful thing and I fear to damage it, but you are trying to absorb so much information that it is not surprising you are getting some things quite wrong. Here is a minor attempt at a minor suite of corrections.

 

Chondrites are meteorites. Do not separate them out from the class.

 

Chondrites and their components have undergone various degrees of melting, but they have not undergone wholesale melting and differentiation, as is the case with the achondrites, irons and stony irons. (To complicate matters further there is evidence that the parent body for some chondrites has undergone some melting.)

 

While you are correct that a significant proportion of the calcium in chondrites is present in the CAI's, calcium-aluminium rich inclusions, some is also found within the pyroxenes in the chondrules.

 

The Earth did form from chondrites, but not directly. The chondrites accreted to form larger objects - planetesimals - which through a combination of kinetic and radioactive heat melted and formed differentiated bodies with mantle and core. It was the amalgamation of many of these modified bodies which formed the Earth.

 

Thanks for all those points. I agree I am biting off a big chunk at the moment. However I am making fast progress and enjoying the ride. The names , I find a bit daunting, however I also found that when I was teaching, I could never remember all the students names. The concepts I find exciting, always have enjoyed the big picture, and I am determined to get my head around the Time Line ( Galaxies to Today ) . I have spent a lot of time on Quantum Physics ( Plank time to Galaxies ). I need to pause a bit while they sort out the Higgs Field/Boson Mechanism.

 

. Keep with me, don't let me sink ! blink.gif

 

What quite are differentiated bodies ?

 

.

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

  • 1 month later...

The concepts I find exciting, always have enjoyed the big picture, and I am determined to get my head around the Time Line ( Galaxies to Today ) .

 

.

 

I have my first sightings of the EARLY EARTH ( 4,000 MYA To 4500 Million Years Ago . )

Raining down of many meteorites , many including Calcium in some form or other.

 

Artists impression

post-33514-0-71268200-1357258402_thumb.jpg

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

  • 2 months later...

The growing significance of Calcium in our environment, At the Cambrian/Pre cambrian Border as well as and including OUR very bones is substantial.

 

 

 

 

 

 

 

 

post-33514-0-32706600-1363334633_thumb.jpg

 

 

Able to eat Ediacaran Enigmata At The Cambrian/Pre cambrian Border with Calcium Teeth

 

 

 

post-33514-0-82263600-1363333630_thumb.jpg

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

  • 2 months later...

The issue of the Cambrian explosion of life as identified by Fossils has and do raise questions . Sometimes this is explained away by the introduction of bones, shells, teeth and other calcified remains to life forms, making previous life forms seen more as chemical remains.

 

However the points brought forward by the authors of this report point to other reasons. Not the least of which is different atmospheric, and water conditions that prevailed due to massive dissolving and activity on vast regions of exposed rock strata , giving rise to different conditions over a billion years of earths history.

 

I think they are stating that Calcium may well have featured in this huge anomaly , amongst other things.

 

Apparently there is evidence of massive missing layers in the Grand Canyon and elsewhere.

 

There is a more complete report in the attachment below. But I suspect more will follow.

 

 

The Report of the new theory ref above

 

Better Complete link Attachment :-

 

mikedoc.pdf

Edited by Mike Smith Cosmos
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.