MESOZOIC OF SOUTHWESTERN OREGON 537 



etc., have practically not developed at any point. At the time of 

 the writer's visit an oil well was being sunk near the village of Myrtle 

 Creek, and not far from the median line of the Myrtle Creek syncline ; 

 but it had not yet proved of any value. Similar formations in Cali- 

 fornia have yielded some oil, but are not economic producers. 



The sandstones, on account of their general regularity of bedding 

 and fair amount of induration, lend themselves to quarrying and 

 building, and have been used to some extent. The majority are too 

 thin-bedded for this purpose. 



As the conglomerates of the Myrtle were formed after the veination 

 of the Dillard and of the Klamath Mountains schists, it is quite 

 probable that in places they carry placer gold, etc. However, on 

 account of the induration of these conglomerates, the concentration 

 of values may never be found high enough to prove of economic value. 



THE DILLARD SERIES 



General contrast. — In contrast to the above, the Dillard series 

 carries a considerable variety of economic products, especially the 

 results of secondary agents, even though the actual quantities are 

 apparently nowhere in such proportions as to allow of the develop- 

 ment of large properties. 



Quartz veins. — As has already been said, quartz veins and veinlets 

 are rather characteristic of the Dillard series. The veinlets are very 

 common in the cherts, and in the sandstones, especially near igneous 

 rocks. In general, these are not known to carry "values," although 

 in the sandstones and the igneous rocks they grade into veins which do. 



On South Myrtle Creek veins in the "metagabbro" have been 

 found to carry gold, etc., in sulphuret-bearing quartz, and one or 

 two small mining properties have been operated there. A more 

 important field occurs about the headwaters of North Myrtle 

 Creek and some of its tributaries. Placer-mining has been carried 

 on there for years and with quite a satisfactory yield. In the vicinity 

 the basic granular rocks are traversed (as so commonly elsewhere) 

 by small quartz veins, and these are considered the source of the gold 

 in the placers. 



Veins occur in the basic igneous rocks of the Port Orford quad- 

 rangle, and assume some economic importance in the district in 

 which head Sixes River, and Salmon and Johnson Creeks, and in a 



