Page 72 - Global Tectonics

CONTINENTAL DRIFT 59

Baltic shield

Greenland

Russian
platform

African Foreland

Figure 3.5 The fit of the continents around the North Atlantic, after Bullard et al. (1965), and the trends of the
Appalachian-Caledonian and Variscan (early and late Paleozoic) fold belts (dark and light shading respectively). The
two phases of mountain building are superimposed in eastern North America (redraw from Hurley, 1968; the

Confirmation of Continental Drift. Copyright © 1968 by Scientific American, Inc. All rights reserved.)

Precambrian cratons and rocks of Paleozoic age
(Hallam, 1975).
3 Igneous provinces. Distinctive igneous rocks can
be traced between continents as shown in Fig.
3.7. This applies both to extrusive and intrusive
rocks, such as the belt of Mesozoic dolerite,
which extends through southern Africa,
Antarctica, and Tasmania, and the approxi-
mately linear trend of Precambrian anorthosites
(Section 11.4.1) through Africa, Madagascar,
and India (Smith & Hallam, 1970).
4 Stratigraphic sections. Distinctive stratigraphic
sequences can also be correlated between
adjacent continents. Figure 3.8 shows
stratigraphic sections of the Gondwana
succession, a terrestrial sequence of sediments
of late Paleozoic age (Hurley, 1968). Marker
Figure 3.6 Correlation of cratons and younger mobile beds of tillite and coal, and sediments
belts across the closed southern Atlantic Ocean containing Glossopteris and Gangamopteris fl ora

(redrawn from Hurley, 1968, the Confirmation of (Section 3.5) can be correlated through South

Continental Drift. Copyright © 1968 by Scientific America, South Africa, Antarctica, India, and
American, Inc. All rights reserved.) Australia.