. Bulletin of the Geological Society of America. Geology. 556 HEALD AND MATHER RECONNAISSANCE OF EASTERN ANDES stones, the streams traverse deep box canyons, the walls of which rise abruptly from the edges of the swift torrents (see figure 3). However, the existence of the peneplain is still evidenced by the uniformity in elevation of individual ridges, the general absence of prominent peaks regardless of the differing natures of the various geological formations, the uniform decline in elevation from ridge-top to ridge-top progressively toward the east, and by a few plateau-like remnants. Xow
. Bulletin of the Geological Society of America. Geology. 556 HEALD AND MATHER RECONNAISSANCE OF EASTERN ANDES stones, the streams traverse deep box canyons, the walls of which rise abruptly from the edges of the swift torrents (see figure 3). However, the existence of the peneplain is still evidenced by the uniformity in elevation of individual ridges, the general absence of prominent peaks regardless of the differing natures of the various geological formations, the uniform decline in elevation from ridge-top to ridge-top progressively toward the east, and by a few plateau-like remnants. Xowhere in the area between Araui and Santa Cruz is there evidence of Pleistocene Figure 2.—Coclia~bamba-Santa Cruz Geology The barren rounded heights of the Andes, 13,000 to 14,000 feet above the sea, carved in Arani sandstones and shales a few miles south of Vacas, on the Santa Cruz trail. SANTA CRUZ PLAINS To the east of the mountains the country is quite flat and poorly drained. Its elevation is between 1,200 and 1,800 feet above sealevel. A few major streams cross the plains, but side streams flow only during the rainy season, and in other times are represented merely by sand- covered courses. Such rivers as the Piray and Surutu flow in shallow valleys bordered by low hills, some three or four miles apart. Over much of this flat area the rain water collects where it falls, with practi- cally no run-off, and makes bogs and morasses. Stream channels are almost invariably floored with treacherous Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Geological Society of America. [New York : The Society]
Size: 2011px × 1242px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1890
