Origin of late dolomite cement by CO2-saturated deep basin brines: evidence from the Ozark region, central United States

Studies of fluid inclusions in regionally extensive late dolomite cement (LDC) throughout the Ozark region show that CO₂ effervescence was widespread during dolomite precipitation. On the basis of quantitative analyses of inclusion fluids, reaction-path modeling shows that LDC with trace amounts of sulfides can be deposited by effervescence of a CO₂-saturated basin brine as it migrates to shallower levels and lower confining pressures. This precipitation mechanism best explains occurrences of LDC in the Ozark region and may account for LDC found in sedimentary basins worldwide.