SEDNORM-a program to calculate a normative mineralogy for sedimentary rocks based on chemical analyses

A method for calculating a normative mineral distribution, based on the major oxide percentages, has been developed specifically for clastic sedimentary rocks and coal ash. Unlike previous methods, SEDNORM allows some variation in the method of normative calculation depending on the sample type and the range of chemical data available. Options available include changing the clay chemistry, including or excluding certain minerals and, in the absence of certain component analyses, allowing sufficient CO2 and H2O to be added to the system to form selected phases such as calcite until the associated components are exhausted. The method has proved successful for a range of sediment types including sandstones, shales, and carbonate rocks.