# Tag Info

## Hot answers tagged limestone

13

The building material comes from minerals dissolved in the ocean, mainly $\mathrm{Ca}^{2+}$, $\mathrm{Mg}^{2+}$, and $\mathrm{HCO}_3^{–}$, but of course there are all sorts of biochemical details. Most limestone originated as the skeletons of micro- and macro-organisms, such as plankton and coral. The minerals come in turn from the erosion of older rocks (...

9

The turquoise to sky-blue color appearance of freshwater bodies are nicely explained with examples in a 2016 paper by Kumar entitled "Study on turquoise and bright sky-blue appearing freshwater bodies". In this paper, the author explains the cause of these shades of greenish-blue shades found in freshwater bodies around the world and proposes a ...

7

Oolites are limestones that are usually considered as in-organic, although they may have bits of shell/etc in them. These form by the precipitation of calcium carbonate around particles (sand, broken shell, etc) with a process comparable to that of an oyster. Some oolite references: http://www.sandatlas.org/2012/09/oolite/ http://en.wikipedia.org/wiki/...

6

Reading your comments I see that you're asking: so could we find for example 1km high limestone layers on earth ? The answer is definitely yes. Here's an example of a stratrigraphic geological section from Israel: source: Chronostratigraphic table and subsidence curves of southern Israel, Gvirtzman 2004, Israel Journal of Earth Sciences, 53 You can see ...

6

Getting figures on the amount of limestone available is difficult. Apparently "limestone makes up at least 10% of the total volume of all sedimentary rocks". One way to answer your question is by inference. Cement is manufactured from limestone. Current global production of cement is in excess of 3.27 Gt/a and by 2030 it is forecast to be approximately 4....

5

First, let me clarify this again: Al2O3 is not clay. Now, back to topic. You are mixing apples and oranges here. The geological section you are referring it was deposited 2 billion years after the GOE. This was long after all surface iron was oxidised, and abundant oxygen was present in Earth's atmosphere. Nowhere you will see the (oxidized) Ferrum in ...

4

Limestones are usually categorized following the Dunham & Folk classification. Only very rare or special limestones were given a name and these are often named after the location where they can be found e.g. Travertine. The images you provided are not very explicit which makes it literally impossible to clearly identify the limestone. Please consider ...

4

I was unaware of a 0.5 mm maximum rule with ooid size. The Sam Boggs Jr. book on Principals of Sedimentology and Stratagraphy indicates that ooids can grow up to 2 mm. Grains larger than this are pisoids. The size limitation may depend on how you define an ooid. To me, an ooid carbonate grain with a nucleus and concentric layers of calcite or aragonite. ...

3

Yes, there is much more than enough limestone, by several orders of magnitude, to neutralize the acidity that we are creating - so much so that I am not even going to bother with the back of an envelope calculation. Given enough time (many millennia and possibly several million years) this will happen naturally. However,the process of re-equilibration with ...

3

Rate.. no. Brute Force We can treat this as an industrial chemistry question. The brute-force method for carbon sequesteration is simply: Extract CO2 from the air (using the acid/base chemistry, Sodium Hydroxide will scrub it as fast as you can supply air) Reduce CO2 to elemental carbon and oxygen. The exact details are not actually important - that's one ...

3

As already noted by Inkenbrandts answer the size limitation of ooids to 2 mm seems rather arbitrary, from Richter (1983): Though most ooids are smaller than 2 mm, it is not meaningful to postulate a grain size boundary between "ooids" and "pisoids" at a diameter of 2 mm as suggested by Choquette (1978) and Donahue (1978), based on older usage, ...

2

The layers correspond to thousands of years, i.e. 23,000 years in the Danien timeline: The page sais that there is a variation of 23,000 for precession of the equinoxes and 100,000 for variation of ellipticity. https://planet-terre.ens-lyon.fr/image-de-la-semaine/Img421-2013-04-15.xml

2

Photosynthesis is up to about 2% efficient while solar panels are above 20% efficient. So just based on the energy available per unit area of sunlit land or sea, chemical carbon sequestration holds more promise, especially since the area need not be arable. Another advantage of chemical means is that carbon dioxide need not be reduced as far as hydrocarbon, ...

1

Perhaps some of the oldest limestones are the banded Espanola Formation from 2.3 billion years ago. The Oxygenation of the environment happened 2.4 billion years ago. I'll find some references and chemistry info when my web connection works, here are some starter pages.

1

I'm not familiar with the Oregon Coast Range, but limestone is such a ubiquitous and widespread rock that your friend is almost certainly right. For strata to be limestone, they need to have been under the sea when they were laid down. The fact that some are found today near the tops of mountains only means that plate movements have uplifted them since they ...

1

First of all, the rocks do not disappear they dissolve, so they are still there only dissolved into the liquid. You are using an acid (vinegar), this has a low pH. The rocks you are using (limestone) they have a high pH (alkaline). The alkaline rock you add to the acid will dissolve but only until the acid is neutralized. The reaction stops when the pH ...

1

To a first order approximation, the black stuff and white stuff are the same. Both are calcite (CaCO3). The only information I could find online was that it contains some impurities of Mg (as dolomite maybe?) and of Al2O3. This shouldn't matter too much to you. The black stuff is black because it is very fine grained, and of organic origin. This is a ...

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