Page:Field Notes of Junius Henderson, Notebook 1.djvu/76

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the first hills but not beyond. A thinner bed lower down seems more continuous here, but it plays out a short distance to the west. Some of the numerous terraces throughout the formation are conglomeratic but most of them are concretionary. Marls greatly predominate, quite soft except in concretions, effervescing strongly under acid throughout, including conglomerate. Numerous caverns are formed under overhanging ledges by dissolution of the marl beneath the conglomerate. In one place a cavern extended 18 feet back and numerous chimneys admitted storm waters, making underground drainage for some distance. Streams are sand creeks, water from springs disappearing at once, flood waters from storms choked with sand, forming almost flat beds, with steep walls, almost perpendicular. In one place a strong conglomerate passes within three or four feet into marl, with no signs