Precambrian: Formation of continents, Archean ( up to 2.5 b.y.), greenstone belts, ultra-mafic lava (1600° C), pillow lavas, shale (argillite), granite-gneiss complexes, granite intrusions, folded gneiss metamorphics; processes, fast tectonics, accretion of arcs, some liquid water; Proterozoic rocks, quartz-carbonate-shale sequences (passive margins), ophiolites; processes, stable cratons (shield, platform), mid-continent rift, supercontinents

Atmosphere: volcanic outgassing , produce free oxygen, photochemical dissociation of water, photosynthesis, results, BIFS (2.5-2by), red beds (1.8by and younger)

Life: prokaryotic cells, blue-green algae, stromatolites; eukaryotic cells, nucleus, multi-celled, sex; complex multi-celled animals, Ediacaran fauna

How was the Earth different at the beginning of the Archean than it is today?

When did liquid water first appear in large quantities on the Earth's surface? What features indicate the presence of water?

How did the Earth's atmosphere begin? How was free oxygen added to the atmosphere? When did free oxygen become a significant part of the atmosphere? How do we know this date?

What are greenstone belts? What are BIFs? Why don't these rock sequences form today?

Compare and contrast: craton, shield, platform, mobile belt. What were the six main cratons at the beginning of the Paleozoic?