Tectonic chart of Gondwanaland, according to Argand
1 = predominantly sima; 2 = areas where anticlinal sial folding preponderates; I, II, III = the three branches of the inner virgation of the Gondwanaland block; 3 = ridges of sial fold; 4 = trough lines of sial fold; 5 = joint lines; a, b, c = African, Arabian and Indian foothills of Gondwanaland. (Caption from Wegener, 1029.) [Note: Virgation means branching from a center. Sial is continental crust; sima, oceanic crust.]
