Petrology of the Lavas. 



341 



Analyses of Alkalic Basaltic Eocks. 



No. 



sio 2 . . 



AiA . 



Fe,0 3 . 

 FeO .. 

 MgO.. 

 CaO .. 

 Na 2 . 

 K,0 .. 

 H 2 + 

 H 2 0- 

 C0 2 ___ 

 Ti0 2 . . 



P.O.-- 



Cr 2 3 . 



Total . 



I 



11 

 37-01 



III 

 37-50 



IV 



33-89 



V 



36-40 



VI 



VII 



38-79 



42-03 



35-91 



14-55 



8-71 



9-12 



9-93 



12-94 



13-60 



11-51 



5-67 



7-26 



5-59 



15-63 



8-27 



7*55 



2-35 



6-68 



6-71 



8-81 







4-59 



6-65 



5*38 



7-78 



14-83 



13-72 



16-14 



11-44 



6-41 



17-54 



14-65 



15-85 



13-85 



15-19 



14-46 



14-15 



13-57 



2-78 



2-63 



2-69 



2-86 



3-01 



1-83 



1-75 



2-54 



1-84 



0-63 



_ _ - - 



0-97 



0-97 



2-87 



1-99 



1-78 



2-35 



2-90 



2-36 



1-08 



) 



0-67 



. - _ . 



1-05 



_ _ - - 





. 



V9-40 



3-56 







0-27 



1-41 



3-94 





) 



0-80 



3-21 



3-21 



0-64 



0-42 



3-70 



0-23 



n. d. 



tr 



0-90 



1-41 



1-04 



0-57 



n. d. 







0-14 



0-07 



tr 















100-46 



99-97 



100-19 



100-00 



99-84 



99-23 



100-51 



0-647 

 0-142 

 0-036 

 0-093 

 0-195 

 0-262 

 0-045 

 0-027 

 0-110 



0-081 

 0-010 



I. Melilite-basalt, mixed with some monchiquite. Bored well 

 at 1110 feet, Southampton, Bermuda Island. R. C. 

 Wells, U. S. G. S., analyst. 

 II. Melilite-nephelite-basalt. Neuhowen (" by Stetten "), N. W. 

 from Engen, Hegau, Baden. Anal., Fr. Dr. S. Hezner. 

 Rosenbusch, Elem. d. Gest., 3d edit., p. 467, 1910. 



III. Melilite-nephelite-basalt. Kilauea Landing, Kauai Is., 



Hawaii. Anal., W. F. Hillebrand. Contains 0*05 CI, 0*04 

 NiO, 0-15 MnO, 0-07 BaO, 0-05 SrO, 0-05 V 2 O s , 0-02 Zr0 2 

 = 0-43. Bull. 419, IT. S. G. S., p. 179, 1910. 



IV. Melilite-basalt. Hochbohl, by Owen, Wiirtemberg. Anal., 



Meyer, in Stelzner, N. Jahrb. Min., Beil. Bd. ii, p. 398, 

 1882. 

 V. Ouachitite, near Hot Springs, Arkansas. Anal., L. G. 

 Eakins, in J. F. Kemp, Basic Dikes in Arkansas. Ann. 

 Rep. Geol., Surv. Ark., 1890, vol. ii, p. 399. 

 VI. Fourchite, Fourche Mt., Ark. Anals., Noyes and Brack- 

 ett, in J. F. Williams, Igneous Rocks of Ark., Ann. Rep. 

 Geol. Surv. of Ark., 1890, vol. ii, p. 108 includes FeS 2 , 

 0-56. 

 VII. Alnoite, Ste. Anne de Bellevue, by Montreal. Anal., P. 

 H. Le Rossignol, in F. D. Adams, Melilite-bearing Rock, 

 etc. This Journal, vol. xliii, p. 271, 1892. 

 VIII. Molecular ratios of No. I. 



most modern and best analyses I have been able to find are 

 given in Nos. II and III ; they are both not pure melilite- 

 basalts, but contain nephelite and are thus transitional to 

 neph elite-basalt. Rosenbusch remarks that the nephelite- 

 melilite-basalts are characterized, in contrast to the nephelite- 

 basalts, in that the silica is less than 39 per cent, and by the 



