Early Earth

Early EarthEmily CalderMadeline CudmoreRebecca Shatney

Lacking Evidence…

Hadean Era

10 billion years after formation of the universe.

Earth forms from gas and dust. Meteors 500 million years uninhabitable. Hot. Mass increase temp decrease. Early atmosphere-CO2, water vapor,

nitrogen, methane, ammonia. Little or no oxygen. UV rays. Meteor collisions decrease temp

decrease. Surface hardens. Water vapor -> rain ->oceans.

Beginning of life

3.85 million years ago. Greenland. Need organic chemicals. RNA. Underwater geothermal

vents.

Chronometric Defining

According to events. Natural disasters,

discoveries, dating, life… Even period divisions. Random durations.

Neoproterozoic Ediacaran-630 Cryogenian-850 Tonian-1000

Mesoproterozoic Stenian-1200 Ectasian-1400 Calymmian-1600

*Million Years Ago

Mesoarchean

3.2- 2.8 billion years ago. Defined chronometrically. One of the first

supercontinent Vaalbara broke during this time.

Life forms have not changed much.

Neorarchean

2.8 – 2.5 billion years ago. Also defined

chronometrically. Oxygen photosynthesis first

evolved (caused the oxyen catastrophe, which was in the paleoproterzoic era).

The supercontinent Kenorland was formed around 2.7 billion years ago.

Life forms have not changed much.

Paleoprotoerzoic Era

Statherian, Orosirian, Rhyacian, Siderian.

2.5 to 1.6 billion years ago. Continents first stabilized.

Ur Arctica Atlantica Nena Columbia

Anaerobic life. Life using oxygen and photosynthesis

appeared. Oxygen Catastrophe. Fossil evidence of the first eukaryotes. Paleontological evidence-1.8 billion

years ago- 450 days a year and 20 hours a day.

Mesoproterozoic Era

Stenian, Ectasian, Calymmian. 1.6 to 1.0 billion year ago. Supercontinent Rodinia. Great floodplain. Sexually reproducing life

appears. Multi-cellular animals. Oxygen levels rise significantly. No big natural disasters or

events. Continent pieces expand,

causing the ocean to shallow.

Neoproterozoic Era

Ediacaran, Cryogenian, Tonian. 1.0 billion to 542 million years ago. Rapid melting of all ice caps on the

world. Breakup of Rodinia. Formation of Pannotia. Rise in carbon dioxide leads to mini ice

age. “Snow Ball Earth”. Rise of soft-bodied multicellular

organisms. Diseases appear. Corals, sea anemones, hydras, jellyfish,

simple metazoa. Not organs Just a body cavity or stomach Mouth, usually surrounded by

tentacles.

http://www.youtube.com/watch?v=hSdlQ8x7cukhttp://www.youtube.com/watch?v=hSdlQ8x7cuk

Citations

http://www.mahjoob.com/en/forums/showthread.php?t=275459 http://lena-panthera.deviantart.com/art/Carte-de-Vaalbara-map-173079888 http://www.geol.umd.edu/~tholtz/G102/102arch2.htm http://en.wikipedia.org/wiki/Neoarchean http://en.wikipedia.org/wiki/Mesoarchean http://bio1152.nicerweb.com/Locked/media/ch25/clock.html http://astroclock2010.files.wordpress.com/2010/05/hadean_earth_space_art.jpg http://www.sciencephoto.com/image/134450/530wm/C0071453-Formation_of_the_Earth,_artwork-

SPL.jpg http://www.fossilmuseum.net/Paleobiology/Images/cyanobacteria.jpg http://science.nationalgeographic.com/science/prehistoric-world/precambrian http://en.wikipedia.org/wiki/Paleoproterozoic http://essayweb.net/geology/timeline/paleoproterozoic.shtml http://palaeos.com/proterozoic/proterozoic.htm http://essayweb.net/geology/timeline/mesoproterozoic.shtml http://www.pbs.org/wgbh/evolution/change/deeptime/precam.html