Interactive Utility

TAS Plot

Volcanic Classification

Total Alkali-Silica Diagram

An interactive TAS plot. Enter sample points as SiO2 and total alkalis (Na2O + K2O), and they will be plotted directly on the diagram.

SiO2 vs Na2O + K2O

374145495357616569737713579111315foiditetephrite(ol<10%)basanite(ol>10%)picro-basaltbasalttrachy-basaltphono-tephritebasaltictracy-andesitetephri-phonolitebasalticandesitetrachy-andesitephonoliteandesitetrachyte (q<20%)trachydacite (q>20%)daciterhyoliteSiO2 (wt., %)Na2O + K2O (wt., %)

Sample input table

Leave the table empty if you only want to inspect the TAS framework, or add your own samples to plot them directly.

LabelSiO2 (wt, %)Na2O + K2O (wt, %)

Notes

Enter SiO2 and total alkalis for any volcanic sample. Labels are optional, but they help when several points are plotted together.

Inputs

SiO2 in % and Na2O + K2O in %. Decimal comma also works.

Framework

Next Step