94 



cox. 



Table I. — Analyses of the finer ejecta from Taal Volcano and of samples of 



volcanic tuff. 

 [Numbers give percentages.] 



Constituent. 



NOT READILY SOLUBLE IN 

 WATER. 



Silica (SiOj) 



Alumina (AljOs) 



Ferric oxide (FejOs) 



Ferrous oxide (FeO) 



Lime (CaO) 



Magnesia (MgO) 



Soda (NajO) 



Potash (K,0) 



Loss on ignition 



Water (HjO) (below 105-110°) . 



Titanic oxide (TiOj) 



Manganese oxide (Mn304) 



Sulphuric anhydride (SO3) — 



Free sulphur (S) 



Phosphoric anhydride (P2O5). 



READILY SOLUBLE IN 

 WATER, f 



Silica (SiOj) j. 



Iron and aluminium oxides 



(R,03) 



Lime (CaO) 



Magnesia (MgO) 



Soda (NajO) 



Potash (K2O) 



Manganese oxide (MusOi) 



Sulphuric anhydride (SO3) 



Phosphori&anhydride (PjOs). 

 Chlorine (CI) 



Total . 



Finest ash from 

 upper southern 

 slope of Taal. 



I». 



45.76 

 14.57 

 2.89 

 5.20 

 6.94 

 2.59 



None. 



None. 



■11.18 



5.03 



1.20 



Trace. 

 9.49 

 0.45 

 0.05 



0.82 



0.01 

 0.16 



None. 

 1.51 

 1.34 



Trace. 

 0.30 



None. 

 0.74 



100. 23 



11. 



OJ 03 ^ 



§ S ■- 



.S g CD 

 cs >-« 



II'. 



50.79 

 16.17 

 3.20 

 5.77 

 7.70 

 2.87 



■51.31 



None. 



L33 



Trace. 



10. .53 



0.50 



0.06 



100. 23 



Ejecta from 



area where 



mud was 1 



cm. deep. 



III'. 



44.63 



13.33 

 3.24 

 5.04 

 6.25 

 2.70 

 None. 

 None. 



■11.19 



6.35 



1.14 



Trace. 



10.11 

 0.37 

 0.03 



0.95 



Trace. 



0.32 

 None. 



2.03 



1.25 

 Trace. 



0.60 

 None. 



0.95 



100. 48 



Si 



*o2 



— -o * 

 5 * >- 



IV ^ 



50.94 

 15.22 

 3.70 

 5.76 

 7.13 

 3.08 



n.36 



None. 



1.30 



Trace. 



11.54 



0.42 



0.03 



TuiT f rom— 



56.84 

 ■=18.46 

 0.75 

 2.51 

 4.78 

 1.59 

 4.12 

 2.72 

 6.95 

 1.76 



Trace. 



100.48 100.48 



Guadalupe. 



VI. 



56.55 



"22.34 



1.87 



4.74 

 2.36 

 2.38 

 2.84 

 4.86 

 2.51 



C) 



100. 44 



VII. 



59.27 



17.06 



2.16 



2.61 



3.37 



1.52 



.49 



3.63 



6.42 



1.34 



0.83 



Trace. 



100. 70 



VIII. 



57.26 

 16.95 



7.55 

 3.56 

 1.10 

 1.64 

 1.86 

 7.65 

 1.43 

 0.91 

 0.23 



100. 14 



° Analyzed mostly by Mr. T. Dar Juan. 



b These numbers are approximately comparable to Columns V to VIII, although it is 

 quite probable that in time the sulphates would be leached out or hydrolysed and give a 

 closer relationship to the tuff which is found in various places in the Island of Luzon than 

 that shown by these analyses. 



<= Includes titanic oxide (TiOo). 



"> Actual loss on ignition — (moisture + sulphuric anhydride + i sulphur). 



« Included in alumina (AI2O3). 



* Three months after collection. 



