406 H. S. WASHINGTON — IGNEOUS COMPLEX OF MAGNET COVE 



Table IT. — Analyses of the Dike Rocks 





I. 



II. 



in. 



IV. 



V. 



VI. 



VII. 



SiO, 



5:). 76 

 23.21 

 1.27 

 3.18 

 0.23 

 2.94 

 6.97 

 7.01 

 1.71 



None. 



None. 

 0.04 



Trace. 



52.91 



19.49 



4.7S 



2.05 



0.29 



2.47 



7J3 



7.88 



1.19 



None. 



0.44 



0.09 



Trace. 



51.35 



20.21 



4.90 



1.53 

 5.75 

 4.43 

 6.68 



0.80' 



44.50 

 22.96 



} 6.84 



1.65 

 8.65 

 6.70 

 4.83 

 2.06 

 1.40 



43.50 



18.06 



f 7.52 



( 7.64 



3.47 



13.39 



2.00 



1.30 



1.22 



2.10 



42.03 



13.60 



7.55 



6.65 



6.41 



14.15 



1.83 



0.97 



1.08 



3.70 



Trace. 



36.40 



A ).,("),• . 



12.94 



Fe,0,. . .. 



8.27 



FeO 



4.59 



MgO 



11.44 



CaO 



14.46 



Na 2 



0.97 



K 2 



3.01 



H a O(ignit.) 



Ti0 2 



2.36 

 0.42 



MnO 





SrO 











P.,0, 



0.28 

 0.04 

 4.01 

 0.06f 







0.57 

 0.08 

 0.56 

 0.05t 



1.04 



S0 3 









FeS 2 





0.52* 

 0.53 

 None. 









CI 



0.02 









C0 2 







3.94 



















100.34 



100.25 



100.04 



99.59 



100.20 



99.23 



99.84 



I. Tinguaite-porphyry, The Ridge; Williams, analyst Williams: Op. cit. , p. 

 266. 



II. Leucite-tinguaite, Neusch's gully; Williams, analyst. Williams: Op. cit, 

 p. 287, with X = 0.48. 



III. " Nepheline-felsite," north of Doctor Thornton's; Noyes, analyst. Wil- 

 liams: Op. cit, p. 263. 



IV. Nepheline-porphyry, Doctor Thornton's; Noyes, analyst. Williams: Op. 

 cit, p. 261. 



V. Amphibole-monchiquite, Dike 159; Noyes, analyst. Williams: Op. cit., p. 

 295. 



VI. Fonrchite, Fourche mountain, Arkansas; Noyes, analyst. Williams: Op. 

 cit, p. 108. 



VII. Ouachitite, Dike 18, near Hot Springs ; Eakins, analyst. Williams : Op. 

 cit, p. 399. Bull. 148, U. S. Geological Survey, 1897, p. 96. 



On comparing the molecular ratios of these dike rocks with those of 

 the main types shown in the diagram it is found that the analyses of 

 the tinguaites and basic nepheline-porphyry fall in very satisfactorily 

 with the lines as there given ; but the analyses of the fourchites, 

 monchiquites, and ouachitites do not fit in at all well, great discrep- 

 ancies occurring all along the lines, rendering them irregular, with sharp 

 and abrupt zigzags. 



*s. 



fNaCl. 



