Palæos:		Geography / Palaeogeography
THE EARTH		Paleogeography

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Geography

Palaeogeography

Continents

Paleogeography

Paleogeography.  Fossil magnetism in rocks is misaligned with the Earth's present magnetic field, and shows that the continents have moved; it indicates the orientation and latitude of a continent at the time when the rocks were formed. This is the primary source of  information about the past locations of continents, but it gives no indication of longitude. Good evidence of recent movements comes from the growth of ocean floors.  Traces of ancient oceans, found among mountains, announce that different pieces of present continents were formerly separated, while evidence of rifting along shore-lines indicates that continents have split asunder. Edges can be put together again by computer programs that reconcile the coarse shapes of continents with the precise geometry of motions on a sphere, to obtain best fit...

The continents can, though, be dismembered into microcontinents, and maps adjusted by evidence of connections and splits between organisms, climate as indicated by characteristic rocks (e.g., coal, or fossil sand dunes), and geological activity. Global patterns of climate and ocean circulation can be inferred...Continental arrangements before 6oo My ago are hazy and controversial, although the existence of earlier supercontinents [similar to Pangea] is presumed

Nigel Calder, Timescale, p.264 (1984, Hogarth Press, London)

Index of Continents

Links

Earth History Paleo Map Project - Christopher R. Scotese

Paleogeographic Atlas Project Home Page - University of Chicago

The Geological Evolution of the Earth - good overview, period by period