Variation Diagrams (weight %). This page will scale and create x-y scatter plots of geochemical data in weight percent units from pre-selected datasets or from a dataset that you upload. Preselected datasets are available from:
PetDB (Compiled and Maintained by EarthChem at Lamont-Doherty)
GEOROC (Compiled by the Max Planck Institute for Chemistry in Mainz)
PETROS Igneous Rock Database (Compiled by Felix Mutschler at Washington State University)
Ueki, Hino, and Kuwatani (2018) (Data compiled from PetDB and GEOROC)
Miscellaneous Example Data Sets. Compiled from a variety of sources.
Use the x-axis and y-axis pulldown lists to choose the plotting variables. Use the Maj+ and REE+ buttons to change between two variable selection lists. Major elements are in units of weight percent oxides (wt% = grams of oxide per hundred grams of rock). Trace elements are in parts per million (ppm = micrograms of the element per gram of rock). FeO(T) is total Fe recalculated as FeO. Note that some datasets report all iron as Fe2O3. The data will scale automatically.
To set your own Min and Max values for the axes: (1) click an "Auto" button the first time you do this, (2) enter Min and Max values (assign both), (3) click the "Set" button. You can zoom and pan by clicking your mouse on one of the data points. Then use the mouse to drag the data points and the scroll wheel to zoom. Click an "Auto" button to reset the scales.
To view other DataSets choose a DataSet Source of preformatted DataSets by selecting from the pull down list. Then choose from among the preselected DataSets from the pull down list.
You can upload your own data from a comma separated value file (.csv) if the first row of the file has the oxide and element labels, and subsequet rows have sample data.
Your uploaded file will not be passed to the other diagram or map pages, but can be uploaded again on those pages. If you want to change the scale after uploading a .csv file, be sure to click an "Auto" button before choosing a new scale for the first time.
If you want to see the contents of a selected DataSet, for more information or to see the format, click on the "View DataSet CSV File" button.
