LEAD AND ANTIMONY. 105 



LEAD. 



Galena is known to occur in the Bettles limestone on the upper waters of the 

 Chandlar and the Koyukuk. It is also reported on East Fork of the Chandlar. 

 Specimens have been seen from Bettles River. Some reported to be from the upper 

 part of Hokotena River or Wild Creek, which is the next large river above John 

 River, were presented to the writer by Messrs. Windrick and Bettles. In one 

 instance the Wild Creek galena is associated with, or partly incloses, quartz crystals 

 five-eighths inch in diameter and an inch or more in length, while in another instance 

 the associated quartz seems to be chalcedonic. The ledge occurs on Michigan Creek 

 (the large east-side tributary of the Hokotena), 3 miles above its mouth, and is sup- 

 posed to be in the Skajit formation. It is reported to be of considerable size. Those 

 who have prospected it are hopeful that it may prove to be of economic value. It is 

 reported to assay some silver and several dollars in gold per ton. 



On the east side of the divide between Middle Fork and South Fork, opposite 

 the head of Minnie Creek, a limestone mountain of considerable size is reported 

 by prospectors, in which galena is said to occur in large quantity. 



ANTIMONY. 



Pebbles and angular fragments of antimony sulphide, sometimes several inches 

 in diameter, are found in the gravels of Gold Creek. A specimen of this mineral 

 was determined in the chemical laboratory of the Survey to be a good grade of rela- 

 tively pure stibnite. It is traversed by quartz stringers. Judging from the resem- 

 blance of the quartz to that seen in the Lake quartz-schists and the locality at which 

 the antimony occurs it is inferred that this rock is probably the source of the ore. 



Owing to the l'emoteness of the z'egion the copper, lead, and antimony ores are 

 not in themselves likely to prove of economic value unless the deposits are very 

 exceptional in quantity and character. 



ZONES OF METALLIFEROUS MINERALIZATION. 



L> the Totsen series. — About 40 miles above the mouth of John River, near the 

 northern edge of the Totsen series, as shown on the geologic map (PI. HI), the mica- 

 schists, in an area several miles wide trending northeast and southwest, across the 

 valley, are stained a pronounced reddish-brown or hematite color, denoting appar- 

 ently a zone in which iron pyrites and other sulphides occur more or less abun- 

 dantly in the schist. Though the rock could not be examined in detail, it seems 

 probable that the stain is due to iron oxide derived from the sulphides b} r oxidation. 

 The residuary soil formed by the disintegration of the schist in this belt is not nearly 

 so red as the rock itself, but is rather of a yellow-ocher or limonite color, which 

 seems to be due to more extensive oxidation and weathering or to leaching out of 

 the mineral matter. 



