GEOL 102 Historical Geology

Spring Semester 2011
The Mesozoic Era II: Cretaceous Geology

Paleogeography and Geology of the Cretaceous:
Continued breakup of Gondwana (which has been intact since the breakup of Pannotia!). Isolated into Africa and a South America + Indomadagascar + Antarctica/Australia unit connected by now-submerged ridges.

As South Atlantic widens, beginning of Andean Orogeny in western South America (a long ongoing mountain building process, still active today).

Equatorial current allows continued warming of tropical seas.

The mid-Cretaceous saw some major worldwide events:

During Late Cretaceous, beginnings of regression, but main regression event not until the Maastrichtian (last Age).

In warm Cretaceous seas, important new types of deposits:

In Early Cretaceous, continuation of Nevadan Orogeny.

During the mid-Cretaceous:

During Maastrichtian:

Cretaceous-Paleogene Boundary: impact of a huge (10 km diameter) asteroid at Chicxulub in the Yucatan Peninsula of Mexico: more on this later!

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Last modified: 14 January 2011