0. II. Hershey — Belt and Pelona Series. 273 



dark-colored, in part black, mica schists, mica slates and fine- 

 textured gneisses accompanied by marbles that extend to and 

 constitute the prominent peak, Marble Mountain. Finally, the 

 series is capped by 100 feet of the Salmon hornblende schist. 

 At Scott I>ar there is an area, probably a mile long and a 

 quarter of a mile in maximum width, of light gray, coarse- 

 textured gneiss that was originally an Archean granite, prob- 

 ably intruded into the Abrams sediments before the 

 development of schistosity. Thence I traced the Abrams 

 schists in a great belt through the Siskiyou Mountains into 

 Oregon. 



In discussing the Pelona schists, which I had mapped in an 

 area about 20 miles long in Los Angeles County,* I suggested 

 that they are of the same age as the Abrams mica schists of 

 the Klamath region. Last year I became acquainted with 

 another area of the Pelona series. It constitutes the greater 

 portion of the Rand Mountains near Randsburg in Kern 

 County, California. It has recently been described by Mr. F. 

 L. Hessf as largely a gray mica-albite schist. In the Atolia 

 scheelite district it is bounded on the southeast by a complex 

 of Archean granitic and dioritic rocks. Hess says, the main 

 granite mass seems to be under and may be older than the 

 schists of the Rand Mountains. I am inclined to agree with 

 him, though it involves an overturn of the strata along the 

 border. A narrow band of marble and limestone follows this 

 border, except where the contact is faulted. In the gray schist 

 area I noted bands of quartz schist, hornblende schist, chloritic 

 schist, and actinolitic schist, characteristic features of the 

 Pelona series. As the two areas are only about 60 miles apart, 

 I correlate them with considerable confidence. I propose, 

 further, to extend the name Pelona series over the Abrams 

 and Salmon formations of the Klamath region. I believe this 

 Pelona series has a definite time position in the geology of the 

 Pacific Coast country, comparable with that occupied by the 

 Belt series of sediments. It is the youngest important Archean 

 series. Further, so far as my observation goes, it is the last 

 sedimentary series preceding the Belt series. 



Kellogg, Idaho. 



*Univ. Calif.,. Bull. Dept. Geol., vol. in, No. 1, pi. 1, 1902. 

 fGold Mining in the Eandsburg Quadrangle, California ; Bull. 430, U. S. 

 Geol. Survey. 



