Page:Field Notes of Junius Henderson, Notebook 4.pdf/102

 black and from fine to coarse. It usually weathers with holes on outside up to half an inch in diameter. It is certainly later than either the tufa or the sandstone, as it is intruded into and through both in a very intricate way - that is the main body of basalt. As the sandstone contains many angular fragments of basalt, however, often 3 to 6 inches in diameter, it is quite evident that there is older basalt in the region, perhaps partly covered by the sandstone. There are probably several flows. At the top of the lower fall (the fall itself being a wall of basalt) is a sandstone about 75 ft. thick. There are occasional angular basalt pebbles all through it, but they are quite abundant in the upper 25 feet. Section looking up stream at lower falls

((drawing in field book))

The sandstone dips S 10°, approximately the same as the slope of the creek below the falls. The lower falls is said to be 90 ft