Chemical classification of common volcanic rocks based on degree of silica saturation and CaO/K2O ratio
![Figure F6. (A) Total alkalis (TAS) vs. silica and (B) potassium vs. silica covariation diagrams for Leg 201 glass analysis. The TAS plot displays the Irvine and Baranger (1971) alkaline/subalkaline (tholeiitic) division Figure F6. (A) Total alkalis (TAS) vs. silica and (B) potassium vs. silica covariation diagrams for Leg 201 glass analysis. The TAS plot displays the Irvine and Baranger (1971) alkaline/subalkaline (tholeiitic) division](http://www-odp.tamu.edu/publications/201_SR/122/images/22_f06.gif)
Figure F6. (A) Total alkalis (TAS) vs. silica and (B) potassium vs. silica covariation diagrams for Leg 201 glass analysis. The TAS plot displays the Irvine and Baranger (1971) alkaline/subalkaline (tholeiitic) division
![TAS Diagram. Total Alkali Silica Diagram. Igneous Petrology. Volcanic Rocks. GSI, GATE, NET, JAM. - YouTube TAS Diagram. Total Alkali Silica Diagram. Igneous Petrology. Volcanic Rocks. GSI, GATE, NET, JAM. - YouTube](https://i.ytimg.com/vi/KOglfzPFjAM/maxresdefault.jpg)
TAS Diagram. Total Alkali Silica Diagram. Igneous Petrology. Volcanic Rocks. GSI, GATE, NET, JAM. - YouTube
![Figure 3. Section of the total alkali-silica diagram (TAS) showing the composition of glass shards from tephra layers and volcaniclastic deposits at Site 974 (electron microprobe data). TAS diagram classification according to Figure 3. Section of the total alkali-silica diagram (TAS) showing the composition of glass shards from tephra layers and volcaniclastic deposits at Site 974 (electron microprobe data). TAS diagram classification according to](http://www-odp.tamu.edu/publications/161_SR/chap_12/images/65_f03.gif)
Figure 3. Section of the total alkali-silica diagram (TAS) showing the composition of glass shards from tephra layers and volcaniclastic deposits at Site 974 (electron microprobe data). TAS diagram classification according to
![Classification of the samples on the TAS diagram, Na 2 O + K 2 O versus... | Download Scientific Diagram Classification of the samples on the TAS diagram, Na 2 O + K 2 O versus... | Download Scientific Diagram](https://www.researchgate.net/publication/288721647/figure/fig3/AS:313806573064194@1451828725837/Classification-of-the-samples-on-the-TAS-diagram-Na-2-O-K-2-O-versus-SiO-2-expressed.png)