Carbonate compensation depth | Wikipedia audio article
Channel: wikipedia tts
Date: 2019-01-17

This is an audio version of the Wikipedia Article:
https://en.wikipedia.org/wiki/Carbonate_compensation_depth


00:02:07 Variations in value of the CCD
00:05:49 See also



Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:
- increases imagination and understanding
- improves your listening skills
- improves your own spoken accent
- learn while on the move
- reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

Listen on Google Assistant through Extra Audio:
https://assistant.google.com/services/invoke/uid/0000001a130b3f91
Other Wikipedia audio articles at:
https://www.youtube.com/results?search_query=wikipedia+tts
Upload your own Wikipedia articles through:
https://github.com/nodef/wikipedia-tts
Speaking Rate: 0.8963859418165789
Voice name: en-US-Wavenet-B


"I cannot teach anybody anything, I can only make them think."
- Socrates


SUMMARY
=======
Calcite compensation depth (CCD) is the depth in the oceans below which the rate of supply of calcite (calcium carbonate) lags behind the rate of solvation, such that no calcite is preserved. Aragonite compensation depth (hence ACD) describes the same behaviour in reference to aragonitic carbonates. Aragonite is more soluble than calcite, so the aragonite compensation depth is generally shallower than the calcite compensation depth.
Calcium carbonate is essentially insoluble in sea surface waters today. Shells of dead calcareous plankton sinking to deeper waters are practically unaltered until reaching the lysocline where the solubility increases dramatically. By the time the CCD is reached all calcium carbonate has dissolved according to this equation:

  
    
      
        
          
            CaCO
            
              3
            
            
              
            
          
          +
          
            CO
            
              2
            
            
              
            
          
          +
          
            H
            
              2
            
            
              
            
          
          O
          
            
              
                
                  
                    
                      ↽
                    
                    
                    
                    
                      −
                    
                  
                
              
              
                
                  
                    
                      −
                    
                    
                    
                    
                      ⇀
                    
                  
                
              
            
          
          
            Ca
            
              2
              +
            
          
          
            (
            aq
            )
          
          +
          2
          
          
            HCO
            
              3
            
            
              −
            
          
          
            (
            aq
            )
          
        
      
    
    {\displaystyle {\ce {CaCO3 + CO2 + H2O = Ca^2+ (aq) + 2HCO_3^- (aq)}}}
  Calcareous plankton and sediment particles can be found in the water column above the CCD. If the sea bed is above the CCD, bottom sediments can consist of calcareous sediments called calcareous ooze, which is essentially a type of limestone or chalk. If the exposed sea bed is below the CCD tiny shells of CaCO3 will dissolve before reaching this level, preventing deposition of carbonate sediment. As the sea floor spreads, thermal subsidence of the plate, which has the effect of increasing depth, may bring the carbonate layer below the CCD; the carbonate layer may be prevented from chemically interacting with the sea water by overlying sediments such as a layer of siliceous ooze or abyssal clay deposited on top of the carbonate layer.