TITLES AND ABSTRACTS OF PAPERS 47 



NEW POINT IN THE GEOLOGY OF THE ADIR0NDACK8 

 BY J. F. KEMP 



(Abstract) 



Recent field observations for the New York State Geological Survey in the 

 vicinity of the Keene Valley have shown in massive anorthosite many in- 

 clusions of strongly foliated gneiss. The foliation of the fragments runs in 

 all directions, even in an area of a few square yards. The Inference will be 

 drawn that the Grenville gneisses were already strongly metamorphosed when 

 the anorthosites entered, and that they are very much older than the in- 

 trusives. 



Presented in abstract without notes. 



Discussion 



Prof. W. J. Miller: Is it not conceivable that the fragments caught up by 

 the anorthosite magma were unaltered sediment and that the inclusions be- 

 came metamorphosed by the heat of the intrusive? 



Further remarks were made by Dr. T. C. Brown. 



MINERALS FROM THE ORE DEPOSITS AT PARK CITY, UTAH 

 BY FRANK R. VAN HORN 



(Abstract) 



During the month of June, 1911, a short time was spent studying the ore 

 deposits at Park City, Utah. At this visit a considerable number of ore 

 specimens were obtained which have since been examined. These investiga- 

 tions show the presence of considerable amounts of bournonite (Pb Cu2)3 Sbg Sg. 

 This fact has never been reported, which is probably due to the similarity of 

 this mineral to tetrahedrite, with which it has probably been confused. The 

 author has found the mineral both at the Silver King and Daly West mines. 

 Calamine, Hg Zua SiOg, was also found at the Quincy mine and has not been 

 previously reported from the district. Jamesonite, Pbz Sbg S5, has been rather 

 doubtfully reported, but the writer has found it in notable amounts, and has 

 obtained an analysis of this mineral as well as that of bournonite. 



Presented in abstract without notes. 



Discussion 



Mr. T. T. Read: This interesting study of the tetrahedrite, which proved to 

 be bourbonite, induces me to draw attention to a similar experience in the 

 copper deposits of Chile, which are familiar to all of us as the "ancestral home" 

 of a number of unusual minerals. It has been generally supposed that ataca- 

 mite here occurs widespread in considerable amount. The more careful in- 

 vestigation consequent upon the development of a successful leaching process 

 at Chuquicamata has disclosed the fact that what was there supposed to be 



