11 votes

Why are alpine river water green - blue?

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 ...
Natura's user avatar
  • 121
9 votes

What are these features on Eldon Hill?

These are marked up on the British Geological Survey's mapping as mineral veins cutting through the limestones, and in the associated memoir as sulphide ore veins. The surface expression that shows on ...
Andy M's user avatar
  • 2,010
7 votes

Are we observing sedimentary rock formation today?

The transformation of sand into sandstone per se cannot be directly witnessed, as it's happening deep in the earth. However, there are types of cementation that happen quickly and in plain view: A ...
Spencer's user avatar
  • 3,548
5 votes
Accepted

Why limestone formation was not a concern in atmosphere oxidation event?

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....
Gimelist's user avatar
  • 23.1k
4 votes

Identification of limestone type

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 ...
Globoquadrina's user avatar
4 votes

Why do ooids not grow larger than 0.5 mm?

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 ...
Inkenbrandt's user avatar
  • 1,035
3 votes

"Bohnerze" pisolitic ore in Switzerland

Bohnerz is the German word for "bean ore". Another translation is "nuggets". You might like to try the Wangen Valley in Switzerland. Pisolitic iron deposits consist of small ...
Fred's user avatar
  • 24.6k
3 votes

Why do ooids not grow larger than 0.5 mm?

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 ...
wienein's user avatar
  • 476
3 votes

Are there sufficient quantities of limestone to dump in the ocean to reverse acidification?

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 ...
Gordon Stanger's user avatar
3 votes
Accepted

Will photosynthesis based carbon sequestration always be more efficient than other chemical means - in terms of rate?

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, ...
Andrew Jon Dodds's user avatar
2 votes

What is the time period of these chalk/clay layers?

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 ...
bandybabboon's user avatar
  • 1,339
2 votes

Will photosynthesis based carbon sequestration always be more efficient than other chemical means - in terms of rate?

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 ...
Chris Jenks's user avatar
1 vote

What are these features on Eldon Hill?

To complete Andy's answer: A History and Gazetteer of the Mines in the Liberty of Peak Forest, Derbyshire, (Heathcote, 2001), published in the bulletin of the Peak District Mines Historical Society. ...
Jean-Marie Prival's user avatar
1 vote

How long ago was the first limestone formed?

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 ...
bandybabboon's user avatar
  • 1,339
1 vote

Is there limestone under the Oregon Coast Range?

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 ...
Michael Walsby's user avatar
1 vote

How acidic waters make rocks disappear?

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)...
trond hansen's user avatar
  • 1,868
1 vote

Specific Chemical Composition of Nero Marquina Marble

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 ...
Gimelist's user avatar
  • 23.1k

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