ACF Diagram (Spear version). This page will scale and plot geochemical data in mole percent units from pre-selected datasets or from a dataset that you upload in weight percent units. Only CaO, Al2O3, MgO, FeO (or FeO(T), and Na2O weight percent values will be used from the input file to plot datapoints on the diagram. Plotting coordinates are those of Frank Spear (1993). The A coordinate is modified for a projection from albite if the "+Ab Projection" box is checked. If the dataset does not have both FeO and Fe2O3 data, you can use total iron as FeO (choose "MgO+FeO(T)" with the pulldown menu for the lower right corner).
To select a composition dataset to plot, choose a DataSetSource and DataSet from the pulldown lists on the right. You may easily upload your own data in weight percent units from a comma separated value file (.csv) if the first row of the file has the oxide labels, and subsequent rows have sample data. Mouse over the plotted data points to display the Sample ID and Name, if these are included in the DataSet .csv file.
Addtional information may be selected to show with the geochemical data. The compositions of common metamorphic minerals can be shown by selecting check boxes or clicking the "Show All Mins" button. Alterntively, idealized mineral assemblages for selected metamorphic facies can be shown by clicking the "Show Idealized Assemblages by Facies" button and selecting a metamorphic facies button. Assemblages are based on those of Spear (1993, Chap.11).
Click on the "Eskola ACF" button to plot data on the ACF diagram propsed by Pentti Eskola (1920).
If you want to see the contents of a Library DataSet, for more information or to see the format, click on the "View DataSet contents" button.
- ACF Diagram (Spear)
