1.   These margins exhibit a much lower level of tectonic activity than the active margins located along convergent plate boundaries and are consequently termed passive continental margins.

2.   Many, though certainly not all, passive continental margins are characterized by major escarpments.

3.   It is possible that a similar flexural effect is associated with great escarpments along passive continental margins.

4.   The latter are primarily submarine features and will not be discussed here although they are certainly an important component of passive margin development.

5.   A feature common to many, but certainly not all, passive continental margins is a broad upwarp which separates the coast from interior basins.

6.   Clearly models of passive margin evolution must be able to account for the development of these upwarps.

7.   Our understanding of the vertical movements of the lithosphere during continental rupture is largely derived from the interpretation of the sediments laid down in passive margin basins.

8.   Interpretations of these sedimentary sequences in conjunction with morphological and structural evidence has led to the development of numerous models of the tectonic evolution of passive margins.

9.   Nevertheless, flexural isostasy provides a possible uplift mechanism for passive margins during their mature stage of development when the effects of the initial thermal uplift have diminished.

10.   A number of other passive margins, however, show no sign of such major volcanism.