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major events in the Proterozoic evolution of Laurentia
an Early Proterozoic episode of amalgamation of cratons, Middle Proterozoic igneous activity, and the Middle Proterozoic Grenville orogeny and Midcontinent rift
Quartzite-carbonate-shale assemblages in Proterozoic rocks were deposited on
passive continental margins and in intracratonic basins
largely responsible for oxygenation of the atmosphere in the Proterozoic
besided photosynthesizing cyanobacteria, this also contributed some oxygen
photochemical dissociation of water vapor
when were most of the world's iron ores deposited as banded iron formation
2.5 to 2.0 billion years ago
oldest fossils of multicellular organisms are
carbonaceous impressions, probably of algae, in rocks 1 billion and 700 million years old
Late Proterozoic Ediacaran faunas include
the oldest well-documented animal fossils other than burrows
other important resources of the Proterozoic
nickel, platinum, and a variety of materials mined from pegmatites
large landmass consisting mostly of North America and Greenland the formed during the Proterozoic
thick accumulations of basaltic lava flows forming extensive lava plateaus occur in the
and exception to Archean and Proterozoic greenstone belt rocks' similarity is that
Proterozoic contain little or no ultramafic rock
most important event in the evolution of life during the Proterozoic was the appearance of
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