112 



" 49. Feldstone-porphyry. Dykes in Mount Squiros." Accoixl- 

 to the prepared rock section a true felsite-porphyry. 



" 53b. Micaceous sandstone. Outcropping between Camp 47- 

 48." According to its lithological character, T sliould call it 

 micaceous schist. 



"55b. Obsidian-bombs. Found between Everard Range and 

 Eraser Range." Most decidedly not of cosmic origin, as sug- 

 gested by you in your private letter to me. At least, so far 

 there are no vitreous masses known to me of meteoric origin. 

 According to their shape, I feel inclined to pronounce them as 

 waterworn, and I should think that the obsidian, fi'om which 

 they are derived, will be found yet in situ. I cannot say any- 

 thing more about them without any knxjwledge of their 

 occurrence. 



" 56a. Gneiss with garnets. Between Camps 53 and 54." The 

 specimen submitted to me is free from felspar, and, therefore, 

 micaceous schist. 



" 67i. Hornblende-schist. Main mass of Eraser Range." Is, 

 according to the microscopical examination of the rock section, 

 an undecomposed diabase, which is distinguished on account oi 

 its containing highly pleoohroitic augite and biotite and apatite as 

 accessory components. 



"72. H or nblendio slate. Between Camps 70 and 71." Tn con- 

 sideration of the microscopical examination of a section of tliis 

 rock, to be pronounced as amphibolite. 



" 75c. Diabase. Dykes in salt lake between Gamps 72 and 

 73." Like 72, and therefore not an intrusive rock. 



" 80. Indurated hornblendic slate. Mount Monger and Hunt's 

 Well." Is indurated argillaceous slate. 



" 87f. Hor7iblende. Golden Valley." Is fibrous tourmaline, 

 as ascertained by the microscope and the blowpipe (containing 

 boracic acid). 



" 96. Augite-schist. Near Camp 101, Mt. Kenneth." Accord- 

 ing to the microscopical examination, rather diorite, whicli con- 

 tains, probably as a secondary formation, small quantities of 

 quartz and epidote. 



"107b. Micaceous schist. Murchison Goldfield." Contains 

 felspar, and therefore to be called gneiss. 



Without any knowledge of the formation and occurrence of 

 the rock specimens submitted to me, I am not able to give any 

 geological notes on them. I have, therefore, limited myself to 

 these few petrographical notes, and I hope and wisli that they 

 will be of some use to you. 



Yours obediently, 



A. W. Stulzner. 



