562 Professor Emerson on HaWs Geological Collections. 



of magnetite, and much disseminated graphite in scales up to 1 mm. in size. The 

 rock is uniformly much decomposed, and coated in many i^laces with a secondary 

 deposit of siderite and limonite. 



Various places in Frobisher Bay. 



50. Epidotic gneiss. 



Small fragments of a red granitoid gneiss with reticulated veins of epidote, 

 and of a red gneiss passing into petrosilex and colored apparently by epidote. 



51. Schistose gneiss. 



A broad freshly-broken plate of very thin-bedded biotite gneiss, the feldspar 

 not abundant and wholly triclinic. 

 Frobisher Bay. 



52. Geanulite. 



A gTanitoid gneiss, wherein red garnets (1-3 mm.) replace the mica entirely. 

 Labeled, "Azoic Eocks, Frobisher Bay." 



53. Banded mica schist. 



A large piece of schist, containing biotite and quartz, arranged in black hori- 

 zontal bands, 1-12 mm. wide, of fresh black biotite and granular quartz, the inter- 

 vening bands containing little or no mica, and consisting of quartz of two l^inds : 

 {a) a reddish somewhat friable granular quartz, through which run (&) flat plates 

 of a gray translucent infiltrated quartz, placed parallel to the bedding, and mani- 

 festly of later formation. 



54. NOEMAL mica schist. 



A typical mica schist of medium grain splitting into flat thin plates, con- 

 taining only quartz and biotite much weathered. 



Labeled, " From trench dug by Martin Frobisher, 1578. Ni-oun-te-lilc.'''' This 

 is an island on the north side of Frobisher Bay. 



55. Mica schist. 



A black wavy mica schist, consisting of black to bronze colored biotite, with 

 little quartz. 



Labeled, " French Head, Field Bay." 

 5G. Mica schist. 



A rock agreeing closely with i)o^ but containing juore quartz and a little 

 feldspar. 



Labeled, "From various places up Bay of Frobisher and near head of it." 

 58. Petuosilex. 



A band of blactk compact hornstone IS mm. wide rnns tiirougli a i)icce of 



