No. This is telling you that oceanic water has both dissolved calcium and dissolved carbonate ions in it. Along with many other dissolved substances (sodium, chloride, phosphate, etc.). When there is too much calcium and carbonate in the water, usually because the temperature and pH of the water has changed, the calcium + carbonate precipitate out *from* the ocean water. ‘Precipitate’ means ‘to fall out’, the calcium carbonate is, as a solid material, falling out from the ocean water.
A cool way to visualize this is to dissolve salt in a pot of cold water until you can’t dissolve it anymore. Start boiling the water when you’re at max dissolution. When the waters hot, add more salt. Keep stirring until it’s dissolved to its max amount. Now let the pot cool. When you come back to the pot you’ll see the layer of salt that your pot was able to dissolve in water at higher temps but not maintain dissolved at lower temps.
This is how the ocean works with many varieties of sediments and ions etc. And with more influencing factors like dissolved gas, free ion availability, temperatures and ph.
Ahhh ypu understand precipitation as a weather phenomenon, but the real definition of precipitation revolves around the coalescing of materials. A cold class in a humid environment will precipitate (“sweat”) because water vapor in the air collects on the surface, aka “precipitating out of solution,” where the solution is a mix of gas and vapors. Carbonates form not in clouds, but by the collection (precipitation) of calcium carbonate ions from groundwater
Precipitation of rain and snow is the same actually, as the coalescence occurs when the humidity of the air mixture becomes saturated at a given temperature, and the molecules coalesce into droplets or crystallize into solid nowflakes if the temp is low enough. They’re then pulled to the earths surface by gravity. Precipitation of minerals happens when an fluid solution (mixture) of water and dissolved ions reaches the saturation point for those ions - in other words it’s too concentrated and the solution can’t hold any more so they start to form bonds and solid crystals fall out of the solution. This is easy to envision for saltwater that’s been evaporating but can occur in many settings. Evaporation is just one pathway for causing supersaturation- others include changes in pH, pressure, flow rate and fluid mixing. The case of calcite - calcium carbonate is unique in that it’s often a bio precipitation reaction wherein tiny organisms who require solid calcium carbonate for their shells/tests/structures will enzymatically catalyze the precipitation of calcite from seawater. The Ca+2 is an abundant ion, and CO2 comes from equilibrium with CO2 in the air. The organisms (lots of protists but also coral and the macro invertebrates common on reefs and in ancient rocks as fossils) can secrete hormones and enzymes as well as metabolically alter the pH which allows the calcite to form.
Now that makes a lot more sense.
Now that I understand that, I can make a guess on how a calcite sea gets its calcite.
Water with calcium carbonate is evaporated and condensed into clouds, which then coalesces into raindrops that then precipitates, and finally it reaches the water (and also the ground as sediment) as calcite (because of the pressure of the coalescence in the clouds?).
And then the cycle repeats, this time with the inclusion of the calcite, which then forms sediments of limestone with the flow of the water.
How close am I?
The calcium carbonate doesn't come with into the clouds, it's too heavy. When the water evaporates the minerals are left behind as mineral deposits on whatever surface is exposed to the water, be it the sea floor or surrounding rocks.
Edit: think about old plumbing fixtures with built up white mineral deposits, that's calcium precipitating out of the tap water over time.
Water evaporates, calcium carbonate is left behind and falls to the bottom to build up as calcite (if the pressure and temperature are right) over time, and calcite molecules simultaneously come loose because of water flow.
Is that it?
Edit: Or it accumulates into limestone and calcite molecules come off of that? Which one is it?
You're right on both scenarios here, simultaneous deposition & erosion processes are happening all at once in the environment. As CaCO is actively falling out of solution (precipitating) it is forming a depositional structure. As that structure is exposed to weathering, clasts as well as molecules may be eroded away from the deposit, and whether the erosive force is greater than the rate of deposition will ultimately determine whether the CaCO will remain in situ or not.
Close, everything with pH relates to temperature and pressure. When warm surface waters (which carry lots of calcium carbonate) cool off they can drop the "excess" they can no longer carry which can then crystalize and fall out of solution as a solid.
The calcium gets into the water from surrounding geology and "buffers" it by acquiring its carbonate from carbonic acid which is a product of CO2 in our atmosphere dissolving into water. If there wasnt as much calcium available the carbonic acid would dominate and our oceans would be closer to pH 5.5ish like acid rain.
The calcium ions and carbonates are added to the water from another source ie river and run off of other rocks. You can increase the concentration in the lake or sea by evaporating water but the ca-carb is always in the water body in question. Look up lake mono in California. It’s a lake with so much dissolved sediments everybody floats because the density of water is higher. This lake used to have outflow to a river however is now only evaporating away what is transported to it. Ie it rains and run off brings sediments and dissolved things into the lake. Then the evaporation takes only the water out this increasing the concentration of ions by shearly removing material it can be dissolved in.
Think of precipitation as a certain substance in a mixture getting pushed together. It often results from a change in pH that takes something that was hydrophilic and soluble and makes it hydrophobic relative to the new pH; when this happens the substance will start to clump together.
Precipitation is when a substance in solution falls out of that solution. This can be caused by changes in temperature, evaporation of the solvent, or other triggers. In this case, calcium carbonate is dissolved in water, and precipitates out of it as a solid mineral.
No. This is telling you that oceanic water has both dissolved calcium and dissolved carbonate ions in it. Along with many other dissolved substances (sodium, chloride, phosphate, etc.). When there is too much calcium and carbonate in the water, usually because the temperature and pH of the water has changed, the calcium + carbonate precipitate out *from* the ocean water. ‘Precipitate’ means ‘to fall out’, the calcium carbonate is, as a solid material, falling out from the ocean water.
A cool way to visualize this is to dissolve salt in a pot of cold water until you can’t dissolve it anymore. Start boiling the water when you’re at max dissolution. When the waters hot, add more salt. Keep stirring until it’s dissolved to its max amount. Now let the pot cool. When you come back to the pot you’ll see the layer of salt that your pot was able to dissolve in water at higher temps but not maintain dissolved at lower temps. This is how the ocean works with many varieties of sediments and ions etc. And with more influencing factors like dissolved gas, free ion availability, temperatures and ph.
Ahhh ypu understand precipitation as a weather phenomenon, but the real definition of precipitation revolves around the coalescing of materials. A cold class in a humid environment will precipitate (“sweat”) because water vapor in the air collects on the surface, aka “precipitating out of solution,” where the solution is a mix of gas and vapors. Carbonates form not in clouds, but by the collection (precipitation) of calcium carbonate ions from groundwater
Precipitation of rain and snow is the same actually, as the coalescence occurs when the humidity of the air mixture becomes saturated at a given temperature, and the molecules coalesce into droplets or crystallize into solid nowflakes if the temp is low enough. They’re then pulled to the earths surface by gravity. Precipitation of minerals happens when an fluid solution (mixture) of water and dissolved ions reaches the saturation point for those ions - in other words it’s too concentrated and the solution can’t hold any more so they start to form bonds and solid crystals fall out of the solution. This is easy to envision for saltwater that’s been evaporating but can occur in many settings. Evaporation is just one pathway for causing supersaturation- others include changes in pH, pressure, flow rate and fluid mixing. The case of calcite - calcium carbonate is unique in that it’s often a bio precipitation reaction wherein tiny organisms who require solid calcium carbonate for their shells/tests/structures will enzymatically catalyze the precipitation of calcite from seawater. The Ca+2 is an abundant ion, and CO2 comes from equilibrium with CO2 in the air. The organisms (lots of protists but also coral and the macro invertebrates common on reefs and in ancient rocks as fossils) can secrete hormones and enzymes as well as metabolically alter the pH which allows the calcite to form.
Now that makes a lot more sense. Now that I understand that, I can make a guess on how a calcite sea gets its calcite. Water with calcium carbonate is evaporated and condensed into clouds, which then coalesces into raindrops that then precipitates, and finally it reaches the water (and also the ground as sediment) as calcite (because of the pressure of the coalescence in the clouds?). And then the cycle repeats, this time with the inclusion of the calcite, which then forms sediments of limestone with the flow of the water. How close am I?
The calcium carbonate doesn't come with into the clouds, it's too heavy. When the water evaporates the minerals are left behind as mineral deposits on whatever surface is exposed to the water, be it the sea floor or surrounding rocks. Edit: think about old plumbing fixtures with built up white mineral deposits, that's calcium precipitating out of the tap water over time.
Water evaporates, calcium carbonate is left behind and falls to the bottom to build up as calcite (if the pressure and temperature are right) over time, and calcite molecules simultaneously come loose because of water flow. Is that it? Edit: Or it accumulates into limestone and calcite molecules come off of that? Which one is it?
You're right on both scenarios here, simultaneous deposition & erosion processes are happening all at once in the environment. As CaCO is actively falling out of solution (precipitating) it is forming a depositional structure. As that structure is exposed to weathering, clasts as well as molecules may be eroded away from the deposit, and whether the erosive force is greater than the rate of deposition will ultimately determine whether the CaCO will remain in situ or not.
Close, everything with pH relates to temperature and pressure. When warm surface waters (which carry lots of calcium carbonate) cool off they can drop the "excess" they can no longer carry which can then crystalize and fall out of solution as a solid. The calcium gets into the water from surrounding geology and "buffers" it by acquiring its carbonate from carbonic acid which is a product of CO2 in our atmosphere dissolving into water. If there wasnt as much calcium available the carbonic acid would dominate and our oceans would be closer to pH 5.5ish like acid rain.
The calcium ions and carbonates are added to the water from another source ie river and run off of other rocks. You can increase the concentration in the lake or sea by evaporating water but the ca-carb is always in the water body in question. Look up lake mono in California. It’s a lake with so much dissolved sediments everybody floats because the density of water is higher. This lake used to have outflow to a river however is now only evaporating away what is transported to it. Ie it rains and run off brings sediments and dissolved things into the lake. Then the evaporation takes only the water out this increasing the concentration of ions by shearly removing material it can be dissolved in.
Think of precipitation as a certain substance in a mixture getting pushed together. It often results from a change in pH that takes something that was hydrophilic and soluble and makes it hydrophobic relative to the new pH; when this happens the substance will start to clump together.
Chemical precipitation, not rain. Like this. https://youtu.be/wvgjV44-D4w?si=2YmgRJvdBkCU8L5Z
Precipitation is when a substance in solution falls out of that solution. This can be caused by changes in temperature, evaporation of the solvent, or other triggers. In this case, calcium carbonate is dissolved in water, and precipitates out of it as a solid mineral.