. Bulletin of the Geological Society of America. Geology. A I Figure 2.—Illustrations of marginal Erosion The sketches iUustrate marginal erosion of deposits in a warped or slightly folded basin, with subsequent deposition of a conglomerate partly composed of material derived from the exposed edges of the lower beds. Bed 2 should haye been represented as reach- ing the surface at the left of the lower sketch. been entirely eroded away. It seems rather that nearly all surface degra- dation of considerable magnitude has ever been to the positive areas. This commonly involved the edges
. Bulletin of the Geological Society of America. Geology. A I Figure 2.—Illustrations of marginal Erosion The sketches iUustrate marginal erosion of deposits in a warped or slightly folded basin, with subsequent deposition of a conglomerate partly composed of material derived from the exposed edges of the lower beds. Bed 2 should haye been represented as reach- ing the surface at the left of the lower sketch. been entirely eroded away. It seems rather that nearly all surface degra- dation of considerable magnitude has ever been to the positive areas. This commonly involved the edges of the marine sediments, which overlapped the flanks of such upwarped areas, and sometimes also the thinning sheets covering them were removed. But over the broader nega- tive areas, particularly in the Paleozoic, erosion processes have always been comparatively negligible in their effect on consolidated deposits. It is not my intention to deny that great elevations have been reduced at times to baselevel. Indeed, as is indicated by occurrence of clastic deposits in certain sections, I think this occurred repeatedly in the same. 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]
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1890
