Today Pre Cambrian Geology DUE Coastal Geology Project

• Today – Pre Cambrian Geology – DUE: Coastal Geology Project • Monday – Paleozoic Tectonics – LAB Geology of North America – DUE: Choice of Fossil for Fossil Poster • Next Wednesday – Paleozoic Climate & Life – Mesozoic Tectonics

Outline of Pre-Cambrian Time

• • Age & Origin of Earth Oldest Rocks & Minerals Archean Tectonics Origin of Atmosphere & Life

The Oldest Terrestrial Rocks: Acasta Gneiss 4. 0 billion years old! Source: Sam Bowring/MIT

The Oldest Rocks on Earth : Meteorites 4. 5 billion years old! Source: http: //www-curator. jsc. nasa. gov/outreach 1/expmetmys/slideset/Slides 16 -20. htm http: //pds. jpl. nasa. gov/planets/captions/smallbod/iron. htm

01_13 and 15. jpg

Zoomable Art PC Mac 01_Featured_Art. jpg

23_03. jpg

Hadean: Hell on Earth? (Fig. 13 -4)

Oldest Rocks & Minerals

Archean Crust

World’s Oldest Rock: Acasta Gneiss 4. 0 b. y. (Fig. 12 -25)

Source: http: //www. gly. fsu. edu/~salters/GLY 1000/13 Age_of_Earth/Slide 19. jpg

World’s Oldest Mineral Grain: Zircon form Jack Hills Australia Source: http: //www. geology. wisc. edu/zircon/Earliest%20 Piece/Earliest. html

Australian Craton Source: http: //earthobservatory. nasa. gov/Study/Zircon/

Jack Hills Metaconglomerate Source: http: //www. geology. wisc. edu/zircon/Earliest%20 Piece/Earliest. html

World’s Oldest Sedimentary Rock: Isua Metasediments 3. 8 b. y. Source: http: //news. bbc. co. uk/2/hi/science/nature/3321819. stm

Source: http: //www. geology. wisc. edu/zircon/Earliest%20 Piece/Earliest. html

Archean Tectonics

Why so little Archean Crust?

Granulite/gneiss and greenstone belts

Granulite Greenstone Belts

Archean Pillow Basalts

Formation of greenstone belts Arc Model

Formation of greenstone belts Arc Model (Fig. 13 -5)

Pre-Cambrian of North America

13_06. jpg

For Monday 5/17 • On-line Readings – Early and Late Paleozoic Events