ft ZEOLITES FKOM BITTER HOT SPRING, GRANT COUNTY, 



OREGON 



By T>. F. Hewett 



Geologist, United States Geological Survey 



Earl V. Shannon 



Assistant Curator, United States National Museum 



and 



Forest A. Gonter 



Mineral Analyst, Washington, D. C. 



INTRODUCTION 



The minerals described in this paper were collected in June, 1915, 

 by D. F. Hewett while engaged in making a geological reconnaissance 

 of a region lying west of the Blue Mountains in Oregon for the 

 United States Geological Survey. Recently a study of the minerals 

 was undertaken by E. V. Shannon, of the United States National 

 Museum, who has done the crystallographic and microscopic work 

 and part of the analyses. The remainder of the analyses were made 

 by Forest A. Gonyer. Even though some of the minerals found are 

 uncommon in the United States and are well developed in this area, 

 the study was first undertaken to throw light on the paragenesis of 

 the zeolites, rather than to investigate the characters of the minerals 

 themselves. The lapse of time between the field study and laboratory 

 investigation leaves some doubt that highly satisfactory conclusions 

 regarding the paragenesis have been reached, though the results 

 seem worthy of presentation. 



OCCURRENCE OF THE ZEOLITES 



By D. F. Hewett 



Surface features. — Ritter Hot Spring lies in sec. 6, T. 8 S., R. 30 

 E., Willamette meridian. Grant County, on the north side of the 

 Middle Fork of John Day River, and about 45 miles north of John 

 Day on the road from that town to Ukiah, Umatilla County. In 

 this region the three main forks of John Day River flow generally 



No. 2737.— Proceedings U. S. National Museum, Vol. 73, Art 16 



88909—28 1 J 



