482 R. ARNOLD RECONNAISSANCE OF THE OLYMPIC PENINSULA 



conglomerates, sandstones, and shales exposed in the Cape Flattery prom- 

 ontory, and also the sandstones and shales exposed in the hills south of 

 the Bogochiel river, come under the same head. The thickness of this 

 series as exposed in sections along the strait, which, by the way, virtually 

 parallels the strike of the beds for most of the distance from Freshwater 

 bay to Neah bay, is about 3,650 feet. The Waatch-Neah Bay section, 

 which cuts directly across the strike of the great Cape Flattery mono- 

 cline, exposes approximately 15,000 feet of conformable strata, most and 

 possibly all of which may be Oligocene-Miocene. 



The conglomerates of the series are usually quite coarse and hard and 

 consist of pebbles and cobbles of quartzite, jasper, black slate, and occa- 

 sional granitics. They are found mostly at the base and near the top of 

 the series along the straits and in the middle of the series on the Cape 

 Flattery promontory. The zone of conglomerate in the middle of the 

 Cape Flattery section may be the equivalent of the basal conglomerates of 

 the series as developed unconformable above the Eocene around Crescent 

 bay. If so, the sandstones at the base of the Cape Flattery section are 

 older than any of the Oligocene-Miocene beds exposed on the strait. The 

 base of the Cape Flattery section is unknown, as the lowest beds exposed 

 in the section are separated from the subjacent rocks by a fault. 



The sandstones of the Clallam formation are for the most part thin 

 bedded, hard and resistant to erosion, and are extremely fossiliferous in 

 certain localities, notably east of Clallam bay. They are found at the 

 base and near the top of the Cape Flattery section and below the upper 

 conglomerates east of Clallam bay. 



The shale of the Oligocene-Miocene occurs principally in the middle of 

 the formation along the strait. The lower part of the shale is thinly and 

 plainly laminated, but higher up becomes almost massive clay. Figure 

 2, plate 57, shows a characteristic exposure of the laminated shale. The 

 overthrusting of the beds exhibited at this particular locality is very un- 

 usual, as the strata along this portion of. the coast ordinarily lie in low 

 simple folds. The shale is gray in fresh exposures, but becomes more or 

 less oxidized upon exposure. Sandstone dikes, probably derived from in- 

 terbedded sandstones, cut the shales in the region east of the mouth of 

 the Pysht river, and near Gettysburg hydrogen sulphide gas was noticed 

 escaping from cracks in the shale along the beach. Figure 1, plate 58, 

 illustrates the ramification of one of the dikes, while figure 2, plate 55, 

 shows a characteristic beach formed by the truncated beds of the soft 

 clay-shale. Fossils are abundant and beautifully preserved throughout 



