Carbon-Silicate Cycle By: Tyler Molton & Michael A. Logan What is carbon silicate? • Defined as the geochemical cycle that is naturally occurring reversible chemical reaction with summary equation CaSiO3+CO2<=>CaCO3+SiO2. • reaction is generally shifted in the favor of carbonate formation under near surface temperature and pressure conditions, but shifts to silicate formation at temperatures above 300 °C The cycle as a process • This cycle begins when CO2 in the atmosphere dissolves in the water to form weak carbonic acid that falls as rain. • The second step is then the acidic water travels through the ground and creates erosion of the Earth’s rocks that are silicate-rich. • The erosion of the rocks release ions like calcium and bicarbonate • Lastly the ions enters the grounds surface and eventually travels to the ocean. Geological Importance • This cycle is important to stabilize the concentration of carbon and silicone in the atmosphere. • It can create negative feedback on the global temperature with a typical time scale of a few million years, which effectively counters water vapor and carbon dioxide short-term positive feedback. Diagram References • http://www.learner.org/courses/envsci/vis ual/img_med/geochemical_carbon.jpg • http://www.google.com/search?hl=en&defl =en&q=define:CarbonSilicate+cycle&ei=N8qCS93QOYy1tgeoxv3 dBg&sa=X&oi=glossary_definition&ct=title &ved=0CAYQkAE • http://en.wikipedia.org/wiki/Carbonatesilicate_cycle