Proterozoic Eon = 2.5 billion years ago to 542 million years ago.
Comprises 42% of Earth history.
The beginning of the Proterozoic at 2.5 by marks the beginning of:
Proterozoic Eon can be divided into three eras:
Proterozoic rocks are easier to study than Archean rocks because they are less altered.
They are more difficult to study than Phanerozoic rocks because they lack the abundant fossils.
Precambrian provinces of North America were welded (or sutured) together to form a large continent
called Laurentia during the early Proterozoic.
Suturing occurred along mountain belts or orogens.
Provinces were assembled by about 1.7 by.
Laurentia continued to grow by accretion throughout the Proterozoic.
Late in the Proterozoic, the continents became assembled into a supercontinent called Rodinia.
Sedimentation on and around the craton consisted of shallow water clastic and carbonate sediments deposited on broad continental shelves and in epicontinental seas.
Proterozoic glaciations occurred during the:
Overview of events of the Proterozoic.
October 30, 2005