Bulletin - United States Geological Survey Volume 157-159 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1899 Excerpt: ...ashes a few rods farther west, away from the river. This volcanic ash bed is horizontally stratified in very thin layers, its texture as tine as flour; its color, for the most part grayish white with yellowish streaks in its upper portion. Muddy sand, passing laterally into obliquely stratified sand with bowlders below 20 Fine greenish clay, thicker at some points 6 Yellow till 4 0 Compact blue till 5 0 Level of the river. In the lower bend the top of the till is scarcely exposed above the surface of the water. No distinct trace of the ash stratum has been found there, and the horizontal base of the loess, which is very distinctly exposed, showing above the carbonaceous layer, is only about 50 feet above the stream. At the town of West Point, in a deep clay pit near the summit of a hill northeast of town, a combined section is as follows: Combined section al West Point, Nebraska. Feet. Loess, sandy above, showing wind-drift structure 30 Dark carbonaceous clay with numerous fragments of shrubs and roots in its upper portion 3--4 Reddish joint clay without pebbles, yellow and laminated above 4-5 On the hillside west, 40 to 50 feet below the bottom of the pit, drift pebbles are scattered. Perhaps 15 feet lower on the hillside, by the schoolhouse, is an exposure showing about 15 feet reddish and yellow till, with a few bowlders. The western side of its lower portion slopes abruptly and is overlain for several feet by horizontally stratified sand, wbich probably corresponds to the sand in the lower part of the high terrace along the Elkhorn farther south. The bottom of this exposure is estimated to be abont 30 feet above the railroad, or 45 feet above the Elkhorn. Where the railroad crosses the west branch of Maple Creek, in the northern part of Colfax County, t...