MBC(1.7): A VISUAL BASIC CODE TO CALCULATE BULK COMPOSITION OF ROCKS FROM CHEMISTRY AND VOLUME PROPORTIONS OF THE PHASES

The MBC _(1.7) is a Microsoft^® visual basic 6.0 program that enables the user to calculate the model bulk composition of the rocks, the chemical formula of different phases and the volume percent of the phases (modal analysis). The bulk composition plays an important role to identify the rocks, origin of the rocks and its tectonic environments. The X-ray fluorescence spectroscopy (XRF) is the method of choice for analysis of major elements and some trace elements. Erroneous analytical results may arise for a variety of reasons, such as, contamination, calibration and peak overlap. In many petrological problems, the scientists interpret the rocks in scale smaller than a typical XRF sample size. Therefore, the XRF is unsuitable for such studies. The MBC program can calculate the model bulk composition of such small scale samples based on the volume of the phases and the molar amount of each oxide per the formula unit of the phases. The program has the ability to calculate the chemical formula of the phases. The output results can be printed out in the form of A₄ papers. The program code and the necessary support files is approximately 1.5 Mb as a self-extracting setup file and can be downloaded from http://wegener.uni-graz.at/group/tabualam/mbc.