PPT Slide
aquatic plants take inorganic carbonates and convert them into CO2, a bi-product of this process is OH- ions and a shift to higher pH
from the phase diagram it can be seen that increasing pH reduces the relative concentration of free CO2, thus high rates of photosynthesis can result in local marl deposition.
- This effect is common in enriched streams with high carbonate content and stones become encrusted with calcite and algal matrix.
- the pH shift is often very localized in the microlayers of water surrounding photosynthetic algae, the precipitation occurs right on top of algal layer resulting matrix constitutes a s rich and complex environment for other algae and invertebrates.