PETROGRAPHIC GEOLOGY AND DESCRIPTIONS. 301 



Barite. Quartzyte. Gabbro.] 



Meg* A coarsely crystallized mass of barite, with a few specks of pyrite, chal- 

 copyrite and sphalerite. 

 No section. 

 Age. A vein in Animikie rocks. u. s. G. 



No. 288B. BARITE, ETC. ( Vein material. ) 



From another vein adjoining No. 288A. 



Ref. Annual Report, vii, pages 16, 17; Annual Report, ix, page 69. 



Meg. A coarsely crystallized mass of barite, with calcite, some earthy material 

 and decayed rock. 



No section. 



Age. A vein in Animikie rocks. 



Eemarl-s. The age of these veins is not known. They are, however, probably 

 of the same age as No. 272, which is clearly later than the dike No. 273. u. s. G. 



No. 289. QUARTZYTE. 



"The country rook at the barite vein." Same locality as No. 288. 

 Ref. Annual Report, ix, page 69. 



Meg. A very fine-grained, greenish-gray quartzyte, showing quartz grains in a 

 darker greenish background. 



Mic. The section, which is a poor one, shows the rock to be essentially the 

 same as No. 268. 



One section. 



Age. Animikie. u. s. G. 



No. 290. QUARTZYTE. (Brownish.) 



"Pair samples of the quartzyte of the region the chief rock of Pigeon Point peninsula, as exhibited on the 

 south shore; obtained three miles west of the extremity. This is a dark-red or brownish quartzyte, becoming 

 black near the dikes, and in some places having red orthoclase mixed with the quartz grains." 



Ref. Annual Report, ix, page 69; Annual Report, x, page 49. 



Meg. Quartzyte, fine-grained and brownish. Small quartz grains and red feld- 

 spars are discernible in a greenish cement. 



Mic. The section is essentially similar to No. 262 except that the greenish 

 chloritic material is in much larger amount. 



One section. 



Age. Animikie. u. s. G. 



No. 291. GABBRO (with olivinej. 



From the extremity of Pigeon point. (Compare Nos. 274, 287, 1843.) Forms the main axis of the peninsula. 

 Ref. Annual Report, ix, pages 69, 70; Annual Report, x, pages 57, 140; Bulletin ii, page 105; American 

 Association for the Advancement of Science, vol. xxx, page 163. 



Meg. Two consolidations are apparent, the first embracing the feldspars and 

 probably olivine, and the second the bulk of the rock. This structure is visible, 



