Hershey — Some Western Klamath Stratigraphy. 63 



eastward, bent down by the thrust. Farther south the strata 

 come up with nearly horizontal attitude to the almost vertical 

 fault plane, leaving no doubt of the reality of the fault. 



In approaching the western border of the belt, the strata are 

 bent up and presently there appears under them a formation 

 made up of white sericitic and green chloritic schists that are 

 evidently sheared rhyolites and andesites. In a very short dis- 

 tance another fault brings down the Bragdon slates. This may 

 be repeated several times in 20 miles, but far the larger por- 

 tion of the area is Bragdon. The shearing becomes more pro- 

 nounced toward the west until traces of the bedding planes are 

 virtually destroyed. 1 now consider the Weitchpec schists, 

 formerly classed as pre-Bragdon, as a portion of this series. 

 Indeed, the apparent ancient schists of Redwood Mountain on 

 the Korbel-Hoopa trail are probably Bragdon, although un- 

 doubted pre-Devonian schists occur in South Fork Mountain. 

 The fact is that the Bragdon spreads over an immense area 

 west of the Orleans fault, running as a broad belt far to the 

 north and as a narrowing belt (in places several belts) south- 

 ward to the Sacramento Valley. Along the trail from Orleans 

 to Hoopa, one is scarcely off it except when on serpentine. 



Wherever the base of this western Bragdon is exposed, it is 

 underlaid by igneous rocks which have characters suggesting a 

 volcanic series. In addition to fragmentals (which appear to 

 be tuffs) and vesicular lavas, the other textures and structural 

 relations of the members certainly oppose the idea that they 

 have been intruded under 5000 feet of sediments. .No dikes 

 rise from the igneous rocks into the slates and there are no 

 inclusions of the latter in the former. Furthermore, the slates 

 pass so readily from contact with one to that with another 

 member as to suggest an erosion interval between the two 

 formations. 



Below the volcanic series there is a great complex of intruded 

 igneous material and of shales, bedded blue cherts and lime- 

 stones identical in character with the Blue Chert series east of 

 the Orleans fault. Its outcrop begins west of Hoopa Yalley 

 as a narrow belt and extends southward, gradually widening, 

 to the border of the Sacramento Valley. The limestone len- 

 tils which it contains are in places quite fossiliferous, contain- 

 ing, if I remember rightly, early and middle Devonian faunas. 



Thus we seem to have on both sides of the Orleans fault a 

 great series (or two lithologically identical series) of shales, 

 cherts and limestones that has everywhere been excessively 

 intruded by igneous material. Over the complex is volcanic 

 rock that may represent two formations on opposite sides of 

 the fault, possessing similar characters. Over this is altered 

 shale thousands of feet thick. But the upper sedimentary 



