Pirsson and Washington — Geology of Red Hill, N. H 273 



Table of Analyses. 





I 



II 



III 



IV 



V 



VI 



SiO„ 



58-30 



59-01 



58-17 



63-71 



0-972 



0-983 



Al a 3 --- 



. 21-38 



18-18 



22-53 



16-59 



0-210 



0-178 



Fe.0,-.- 



. 1-05 



1-63 



1-54 



2.92 



0-007 



o-oio 



FeO 



2-04 



3-65 



1-04 



0-66 



0-028 



0-051 



MgO ... 



. 0-22 



1-05 



0-19 



0-90 



0-005 



0-026 



CaO 



0-95 



2-40 



0"74 



3-11 



0-015 



0-043 



Na„0 ... 



. 8-66 



V-03 



9-62 



8-26 



0-140 



0-113 



K„0 



6-06 



5-34 



4-89 



2-79 



0-065 



0-056 



H o "0+ .. 



. 0-45 



050 



0-90 



0-19 







. . - - 



h;o— .. 



. 0-35 



0-15 



0-07 













TiO, 



o-io 



0-81 



0-31 





0-006 



o-oio 



zi-o; 



0-02 



tr 



0-11 



_ . 











PA-- 



0-04 



tr 



















MnO 



tr 



0-03 



tr 









_ 



BaO 



none 



0-08 



none 







_ 



. 



SrO 







tr 

















so 3 



0-08 























CI 



0'35 



012 











o-oio 



0-003 





10005 



99-98 



100-71 







0=C1 



0-08 



0-03 















Total 



99-97 



99-95 



100-71 



100-19 



I Miaskose, nephelite syenite, Home Quarry, Red Hill, N. H., H. S. 

 Washington analyst. 

 II Umptekose, alkalic syenite, Red Hill, N. H. , (Bayley, loc. cit) Hille- 

 brand anal. 



III Miaskose, neph. syenite, Salem, Mass., (Washington Jour. Geol., vi, 



p. 803, 1898,) Washington anal. 



IV Umptekose, umptekite, Umpjavr, Kola (Ramsay, Fennia, xi, p. 205, 



1894), Petersson anal. 

 V Molecular proportions of No. I. 

 VI Molecular proportions of No. II. 



This is a typical analysis of a lendofelic rock, and needs no 

 special comment. Its nearest geographical relative, the mias- 

 kose (nephelite syenite) of Salem Neck contains more soda but 

 less potash, and otherwise is much like it. 



Classification. — The position of the rock in the quantitative 

 classification is seen in the following calculation of its norm. 



It is therefore persalic, lendofelic. peralkalic and dosodic, and 

 its position in the scheme is given by the coordinates 1, 6, 1, 

 4. It is also in the donelic section of the subrang. It has a 

 normative mode, a granular texture and hornblende — cata- 

 phorite — as a varietal mineral. It is therefore hornblendic- 

 grano-miaskose. 



In the system of classification hitherto prevailing this rock is 

 a nephelite syenite and belongs to the foyaite subdivision in 

 Rosenbusch's sense. 



