. Bulletin of the Geological Society of America. Geology. PRIMARY FRACTURE PATTERN 163 ture lines, and that these "run in the entire region often approximately meridional, generally, however, northeast-southwest or northwest-south- east, and only rarely east-west" (see figure 36). These two dominating y^-^ (// V, \ directions in the diagonal system "^-^ fL/^^^^^'^^^^^—\ V are strikingly brought out by two strong lines of volcanoes—the Cam- ^ y^^^?^'--^^ \Pead5ea eroon fissure bisecting the Gulf of Guinea and the Saint Pauls Kocks— Saint Helena ;^" THE PRIMARY FRAC
. Bulletin of the Geological Society of America. Geology. PRIMARY FRACTURE PATTERN 163 ture lines, and that these "run in the entire region often approximately meridional, generally, however, northeast-southwest or northwest-south- east, and only rarely east-west" (see figure 36). These two dominating y^-^ (// V, \ directions in the diagonal system "^-^ fL/^^^^^'^^^^^—\ V are strikingly brought out by two strong lines of volcanoes—the Cam- ^ y^^^?^'--^^ \Pead5ea eroon fissure bisecting the Gulf of Guinea and the Saint Pauls Kocks— Saint Helena ;^" THE PRIMARY FRACTURE PATTERN OF THE EARTH'S SHELL From what has been said in the foregoing sections, it is evident that the repeating patterns of relief and of structure which are encountered in difi^erent parts of the same conti- nent, and in different continental areas as well, are in reality but one, of which, however, some of the four component lineament series may locally be either wanting or but faintly indicated (see figure 30, page 157). This recognition within the fracture complex of the earth's outer shell of an unique and rela- tively simple fracture pattern, com- mon to at least a large portion of the surface, obscured though it may be in local disU^icts through the superimposition of more or less dis- orderly fracture complexes, must be regarded as of the most fundamental and far-reaching importance. It points inevitably to the conclusion that more or less uniform conditions of stress and strain have been com- m,on to probably the earth's entire outer FiGURio 36.—Oriented Drainage and Struc- ture Lines of East Central Africa (After Suess) ""^ See Proceedings of the American Philosophical Society, vol. 48, 1909, pp. 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 Soci
Size: 940px × 2659px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1890
