398 Egglest 



cm — 



F 



i 



005 



Or.O, 



None 



BaO 



002 



SrO 



Trace 



PeS, 



0-61 



Fe 7 S s 



013 



Li.,0 



None 



Eruptive Rocks at Cutting sville, Vt. 

 II in IV v VI 



Sum 99-64 100-45 100-47 .100-72 100-79 10000 



I = Sodalite-nephelite syenite, type phase (nordmarkose), Cuttingsville, 

 Vt., H. E. Merwin, analyst. > 



II r= Sodalite syenite (pulaskose), Square Butte, Mont. 

 Ill = Pulaskite (pulaskose), Fourche Mts., Ark. 

 IV = Foyaite (phlegrose), Fourche Mts., Ark. 

 V = Aegirite — kataf orite foyaite (miaskose) , Heum, Norway. 

 VI r= Pulaskite (average of 5 analyses, E. A. Daly). 



II, III, IV, V Quoted from Washington, H. S., U. S. Geol. Surv., Prof. 



Paper 14, pp. 201, 199, 195, 211, 1903. 

 VI " " Daly, B. A., "Igneous Bocks and Their 



Origin," p. 22. 



The rock is a nordmarkose, near phlegrose, with the 

 following norm: 



Orthoclase 32-80 Magnetite -93 



Albite 53-45 Ilmenite -61 



Anorthite 5-28 Corundum 2-35 



Hypersthene 1-72 Water, etc 2-51 



99-65 



A comparison of columns I, III, and VI tends to sup- 

 port the view that the sodalite-nephelite syenite is a 

 phase of the Cuttingsville pulaskite. 



Augite Syenite {Nordmarkite) (5, fig. 1). — In the mid- 

 dle of the last century, during the construction of the 

 railroad, openings were made in the north end of Granite 

 Hill, and a considerable amount of stone quarried for 

 bridge foundations. This stone is popularly known as 

 green granite from its light olive-green color. The grain 

 is usually medium, but there are fine-grained and decid- 

 edly coarse-grained phases. In total areal extent it is 

 probably second only to the pulaskite. 



The type phase is a medium-grained aggregate largely 

 of hypidiomorphic feldspar. Grains of black augite and 

 occasional small grains of quartz are usually discernible. 



The rock on the fresh fracture is bluish gray to gray- 

 green in color. This color changes in a few weeks in- 

 doors to olive or brownish green. 3 The change is pre- 



3 This remarkable behavior is paralleled in the case of the nordmarkite of 

 Ascutney Mountain. (See E. A. Daly, TJ. S. Geol. Surv. Bull. 209, p. 

 51, 1903.) 



