230 WATSON AND CLINE ROCKS OF THE BLUE RIDGE REGION 



I II III IV V VI VII VIII 



NiO, CoO ! , .02 , 



p,-. \ none trace none trace trace < „- 1 .37 



S none .25 .16 trace trace .14 .26 



99.58 101.39 100.71 100.37 100.99 100.84 99.98 100.75 



Excess O 30 



101.09 



I. Apatite-ilmenite gabbro (norite) from southeast slope of Rocky Row 

 Mountain, about 3 miles north of James River, Amherst County, Vir- 

 ginia. J. G. Dinwicldie, analyst. 

 II. Gabbro-nelsonite exposed on the west side of the Arrington-Roseland 

 Road, 1 mile south of Roseland. Type locality. William M. Thorn- 

 ton, Jr., analyst. Watson and Taber : Bulletin III-A, Virginia Geo- 

 logical Survey, 1913, pages 138-142, especially page 140. 



III. Hornblende gabbro (norite) from the southeast slope of the Blue Ridge 



in Robinsons Gap, Amherst County, Virginia. J. G. Dinwiddie, 

 analyst. 



IV. Gabbro (norite) dike exposed on 100-foot level, 50 feet from shaft, 



General Electric Company's mine, 1.5 miles northwest of Roses Mill. 

 William M. Thornton, Jr., analyst. Bulletin III-A, Virginia Geolog- 

 ical Survey, 1913, page 95. 

 V. Gabbro (norite) in Roseland-Arrington Road, near Mr. Adams' house, 

 about 100 yards south of Roseland post-office. William M. Thornton, 

 Jr., analyst. Bulletin III-A, Virginia Geological Survey, 1913, page 95. 

 VI. Gabbro (norite), Baltimore, Maryland, area. Average of 23 typical 

 specimens. L. McKay, analyst. G. H. Williams : Bulletin 28, United 

 States Geological Survey, 1886, page 39. 

 VII. Gabbro, Woolen Mill, 1 mile west of Elizabethtown, Essex County, New 

 York. W. F. Hillebrand, analyst. J. F. Kemp: Bulletin 138, New 

 York State Museum, 1910, page 40. 

 VIII. Gabbro (norite). Wall rock of titaniferous magnetite deposit, Lincoln 

 Pond, Essex County, New York. George Steiger, analyst. J. F. Kemp : 

 Nineteenth Annual Report of the United States Geological Survey, 

 part iii, 1899, page 407. 



Norms of Oabbros corresponding to Analyses on page 229 



J44 jj JJJ44 jy y yj44 y H 44 yni« 



Q 8.94 7.38 8.94 



Or 6.67 2.78 4.45 12.79 7.23 .06 7.2 5.6 



Ab 16.77 11.00 14.15 19.91 29.34 13.01 26.2 21.0 



An 20.57 6.95 33.64 16.68 25.58 43.9 25.0 19.5 



Di 1.51 21.57 3.43 .92 17.3 12.5 25.9 



Hy 14.10 22.55 9.87 21.05 27.53 11.4 8.1 4.0 



Ol 9.42 8.4 12.8 5.9 



Mt 16.47 2.78 3.02 1.16 4.6 2.3 6.7 



II 19.30 19.15 1.67 8.82 8.36 6.4 9.9 



Hm 1.12 



Ap 9.07 11.42 .34 4.03 .31 1.3 



** Norms calculated by Dr. H. S, Washington. 



