Geology Reference
In-Depth Information
◗
Figure 22.1
(Continued)
60
60
Eurasia
Greenland
30
30
North
America
Tethys Ocean
0
0
India
Africa
30
30
South
America
Australia
60
Antarctica
Shallow sea
Late Cretaceous Period
Deep ocean
Lowlands
Mountains
Desert
Glaciation
C
low southern latitudes and was nearly to the equator. South
America and Africa were widely separated, and Greenland was
essentially an independent landmass with only a shallow sea
between it and North America and Europe (Figure 22.1c).
A global rise in sea level during the Cretaceous resulted
in worldwide transgressions onto the continents. Higher
heat fl ow and rapid expansion of oceanic ridges was respon-
sible for these transgressions. By the Middle Cretaceous, sea
level was probably as high as at any time since the Ordovi-
cian, and about one-third of the present land area was inun-
dated by epeiric seas (Figure 22.1c).
The final stage in Pangaea's breakup occurred during
the Cenozoic. During this time, Australia continued moving
northward, and Greenland was completely separated from
Europe and North America and formed a separate landmass.
◗
Figure 22.2
Evaporite Formation Evaporites accumulated in
shallow basins as Pangaea broke apart during the Early Mesozoic.
Water from the Tethys Sea fl owed into the central Atlantic Ocean,
and water from the Pacifi c Ocean fl owed into the newly formed Gulf
of Mexico. Marine water from the south fl owed into the southern
Atlantic Ocean.
Global Climates and Ocean Circulation
Patterns
By the end of the Permian Period, Pangaea extended from
pole to pole, covered about one-fourth of Earth's surface,
and was surrounded by Panthalassa, a global ocean that
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