How can the Carbon-silicate cycle provide a negative feedback mechanism to control the temperature?

The carbon (carbonate) is a mechanism for ridding the ocean of excess carbonates.  It simply gets deposited as chemical precipitates and animal shells as sediment.  

Calcium silicates will rid themselves of the silicate ions and get replaced with carbonate ions.  Anywhere near the surface, the carbonate is more stable.  This is somewhat dwarfed by the carbonate formation in the first paragraph in my opinion but is still important.

 I also am skeptical that it controls temperature because carbon dioxide changes with temperature.  In other words, temperature drives the CO2 change.  CO2 has not been demonstrated (except in models and theory) to drive temperature changes.