276 Pirsson and Washington — Geology of Bed Hill, N. H. 



No. I No. II 



Or ._ 36-14 31-14 



ai Sal 85-61 Tr _ , 



Ab.. 37-20 42-97 = — = = 6-3 = II, Dosalane 



Fern 13-49 ' 



An.. 2-78 3-06 



■vt L 8-44 



Ne._ 13-92 7-10 —=——— = 0-1 1 = 5, Germanare 



F 77-17 ' 



So .. 4-85 1-34 Sal. = 85'61 



Di .. 1-08 745 Na 2 0^+K 2 0^_169_ Umptek- 



01.. 1-05 2-20 CaO' TTT - ' *' ase 



Mt._ 1-62 2-32 K O' 56 



II... 0-91 1-52 ^ _„-,. —^r, = — - = 0-5, 4, Umptekose 



■d ^ o ca r, nn rem. = 13-49 JNa„0 113 



Rest, 0-94 0-76 - 



Total, 100-49 99-86 



The increased amount of femic minerals carries the rock well 

 over into dosalane ; the diminished amount of lenads places it 

 in. the perfelic order while the rang and subrang remain the 

 same. In No. IV of the table of analyses is given that of the 

 type of this subrang, Ramsay's umptekite from Kola. Rosen- 

 busch classifies it under the same type, which he makes one of 

 the varieties of the alkalic syenites.* 



Contact fades of Nordmarkose. 



It has been previously stated in the description of the geol- 

 ogy of Red Hill that the best exposures for studying the con- 

 tact were found at the foot of the mountain slopes on the east 

 side. The rock of the massif collected at these points is dark 

 gray to dark greenish gray, fine-grained, and generally of a 

 clearly persalic character, though varying in places so that it 

 probably becomes at times a dosalane. 



The study of the sections shows that neph elite and other 

 lenad minerals are absent and replaced by a minute amount of 

 interstitial quartz. Hornblende of an olive-green, strongly 

 pleochroic character is the dominant mineral, sometimes accom- 

 panied or even replaced by a pale green augite. The great 

 mass of the rock is made uj> of alkalic feldspars, microper- 

 thites as previously described, in isodiainetric grains. The 

 fabric is a granular one. The rock is clearly perfelic and per- 

 alkalic, and the character of the feldspars is so evidently like 

 that of the types previously described that it must be dosodic 

 also. This makes its coordinates I. 5. 1. 4, and it is therefore 

 grano-nordmarkose, at times perhaps passing into the previous 

 type — grano-umptekose. It would be the pulaskite or nord- 

 markite of Rosenbusch. 



[To be continued.] 

 * Elemente der Gesteinslehre, 1898, p. 113. 



