# How much of the earth's inorganic material results from organic interaction?
**URL:** https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631
**Category:** Factual Questions
**Created:** [October 23, 2017, 2:55pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631 "2017-10-23T14:55:59Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)
#### Post date: [October 23, 2017, 2:55pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/1 "2017-10-23T14:55:59Z")
See query, which is prompted directly from a comment by **Broomstick** in the current thread ["Does all life depend on life
"](http://boards.straightdope.com/sdmb/showthread.php?t=839530#15):
> [@](#):
>
> …There were probably all sorts of interesting evolutionary things happening in cells for all those billions of years - new means of extracting energy from surroundings, new chemical defenses, new chemical attacks, all sorts of stuff - that we don’t know about because fossils don’t give us that information. But there are indications that lots of stuff was going on - iron pyrites generated from sulfur using bacteria, for instance. Fool’s gold is bacterial poo, in that sense. Banded iron formations may have been caused by life, massive, massive sediments of iron ore that stole oxygen from the air during their formation, keeping atmospheric oxygen levels low until the dissolved iron in the oceans “rusted” out…
Oil and sand I know about, but the fact about “fool’s gold” was new to me (thanks **Broomstick**!), and made me think–after reading another current thread on Gold and neutron star collision–of how much of earth is either elemental or a combination of elements straight from the horse’s mouth, so to speak.
I’m wondering what the percentage might be, perhaps to add another item to the impressive CV of life. Excluding for the moment that biological organisms are also ultimately stardust.
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### Author:  [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)
#### Post date: [October 23, 2017, 3:05pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/2 "2017-10-23T15:05:13Z")
Well, given that the Earth’s biosphere (including sedimentary rock subducted back into the mantle) is only the barest skin on the Earth’s surface, it would have to be far below one percent.
If you limit it to only the upper crust, the percentage would be larger, but I have no idea what that percentage would be.
But to give just one more example of a sizable pile of organic debris, ever hear of [the White Cliffs of Dover](https://en.wikipedia.org/wiki/White_Cliffs_of_Dover)?
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### Author:  [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)
#### Post date: [October 23, 2017, 3:09pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/3 "2017-10-23T15:09:58Z")
ETA to above: stuff in Earth, excluding the comfy-to-us atmosphere. Which points out the query’s limits: the atmosphere created/changed by organisms gave us more of them, which gave us stuff in Earth like oil and sand and rotting everything else.
[ninja’ed]
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### Author:  [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)
#### Post date: [October 23, 2017, 3:11pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/4 "2017-10-23T15:11:02Z")
[Hey, all three threads in a row at this moment…!]
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### Author:  [@Riemann](https://boards.straightdope.com/u/Riemann)
#### Post date: [October 23, 2017, 3:23pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/5 "2017-10-23T15:23:58Z")
> [@Darren\_Garrison](#):
>
> …But to give just one more example of a sizable pile of organic debris, ever hear of [the White Cliffs of Dover](https://en.wikipedia.org/wiki/White_Cliffs_of_Dover)?
All limestone, of course. More than halfway down the Grand Canyon contains substantial amounts of limestone, including the largest cliffs, the Redwall.
> **[Redwall Limestone](https://en.wikipedia.org/wiki/Redwall_Limestone)**
>
> The Redwall Limestone is an erosion-resistant, Mississippian age, cliff-forming geological formation that forms prominent, red-stained cliffs in the Grand Canyon. these cliffs range in height from 150 m (490 ft) to 244 m (801 ft). It is one of the most fossiliferous formations exposed in the Grand Canyon region.
> In 1875, Gilbert recognized and named the Redwall Limestone for the red coloration of its escarpment on either side of Grand Canyon. As originally defined by him, it included some strata...
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### Author:  [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)
#### Post date: [October 23, 2017, 4:29pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/6 "2017-10-23T16:29:21Z")
None of these are examples of organic material \*creating \*inorganic material. All that is happening is that the organic materials shifts and/or concentrates already existing inorganic material.
And that happens during life as well. Humans contain [60 different elements](https://en.wikipedia.org/wiki/Composition_of_the_human_body#Elemental_composition_list). Those will be redeposited after death just as much as limestone is.
No matter how you count it, compared to just the mantle that’s a negligible percentage.
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### Author:  [@Broomstick](https://boards.straightdope.com/u/Broomstick)
#### Post date: [October 23, 2017, 4:33pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/7 "2017-10-23T16:33:31Z")
Sure, but we don’t live in the mantle, we live on the surface of the crust. Maybe the OP wondered how much of _that_ comes from organic interaction?
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### Author:  [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)
#### Post date: [October 23, 2017, 4:49pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/8 "2017-10-23T16:49:46Z")
> [@Broomstick](#):
>
> Sure, but we don’t live in the mantle, we live on the surface of the crust. Maybe the OP wondered how much of _that_ comes from organic interaction?
He mentioned oil. Known deposits of oil are found in the crust, but many scientists suspect that large supplies may be trapped in the mantle and in subducted crust material.
Even if you limit the volume to the lithosphere, it’s _[frikkin’ huge](http://www.madsci.org/posts/archives/1999-11/943288749.Es.r.html)_.
> [@](#):
>
> The lithosphere comprises two shells :the crust and upper mantle that are divided into a dozen or so rigid tectonic plates. The crust itself is divided in two. The sialic or upper crust, of which the continents consist, is made up of igneous and sedimentary rocks whose average chemical composition is similar to that of granite and whose density is about 2.7 g/cm3. The simatic or lower crust, which forms the floors of the ocean basins, is made of darker, heavier igneous rocks such as gabbro and basalt, with an average density of about 3. Taking all of this and some other factors into consideration, we get:
>
> ```
> volume = 5.054 x10^19 cubic meters
> density of 2.7 g/cm3
> mass = 1.365 x10^23 kg = 2.18 % of earth's mass
> = 2.72 % of earth's volume
>
> ```
Would you say that there is more limestone and pyrite and oil than all the water in the world? I doubt it. Yet the water is 0.001% of the lithosphere.
> [@](#):
>
> The Hydrosphere is the layer of water which covers about 71% of the earth’s surface. This layer is the combination of rivers, seas, lakes, underground water, and all the world’s oceans. The average depth of the oceans is 3794 m (12,447 ft), more than five times the average height of the continents. The mass of the oceans is approximately 1.35 quintillion (1.35 × 10^18) metric tons, or about 1/4400 of the total mass of the earth. This is 0.04 % of the earth’s mass.
I’m not seeing any way that “negligible” isn’t the proper term. True, it would help if the OP’s question were better defined, but the thread title asks about “the earth” so we need to start there.
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### Author:  [@Riemann](https://boards.straightdope.com/u/Riemann)
#### Post date: [October 23, 2017, 5:06pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/9 "2017-10-23T17:06:08Z")
> [@Exapno\_Mapcase](#):
>
> None of these are examples of organic material \*creating \*inorganic material. All that is happening is that the organic materials shifts and/or concentrates already existing inorganic material…
I’m not sure what distinction you are drawing here. Matter is never created _ex nihilo_. Are you suggesting that “creation” must involve a chemical reaction, or what exactly? If so, I think your semantics are dubious. By that measure, a beaver does not create a dam, it just shifts and concentrates pre-existing wood.
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### Author:  [@Colibri](https://boards.straightdope.com/u/Colibri)
#### Post date: [October 23, 2017, 5:16pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/10 "2017-10-23T17:16:59Z")
> [@Exapno\_Mapcase](#):
>
> None of these are examples of organic material \*creating \*inorganic material.
Irrelevant, since the OP didn’t ask about organic reactions creating inorganic material. He asked about how much _results from organic reactions._
I agree that the actual percentage is going to be small, even for the lithosphere. However, as mentioned there are extensive amounts of deposits of inorganic rocks produced by organic processes, notably limestone.
Many mineral oxides, which are a significant component of the crust, were created due to the presence of oxygen in the atmosphere, which itself is produced mainly by photosynthetic organisms. So while not produced directly by life, these oxides are produced by one of life’s byproducts. A notable example is the [banded iron formations](https://en.wikipedia.org/wiki/Banded_iron_formation)produced by the Great Oxygenation Event 2.4 billion years ago.
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### Author:  [@Mangetout](https://boards.straightdope.com/u/Mangetout)
#### Post date: [October 23, 2017, 5:39pm UTC](https://boards.straightdope.com/t/how-much-of-the-earths-inorganic-material-results-from-organic-interaction/799631/11 "2017-10-23T17:39:24Z")
I’m not sure the ‘organic/inorganic’ criteria of the OP are terribly clear - I think a better phrasing might (subject to agreement from Leo) be: How much of Earth’s mineral makeup was deposited by, or the remains of, living organisms?