Evolution of Earth Flashcards
Origin and History of Continents
Hot volcanic surface during the Hadean
Principle of Differentiation
First good evidence of plate-tectonics is in the Archean-Protozeroic boundary
Early continents accumulated Felsic Material
The stable interior of the current continents are called cratons they were formed in the Archean
What makes up a craton
The stable interior of current continents are called cratons –they were formed in the Archean
the crystalline core (the shield) and the platform made of sedimentary rocks covering the shield. A lot is added to the edges, which we call an orogen
Discovering of how life might have originated ***Possible test question check story in textbook
There are isolated ecosystems around hydrothermal vents in the ocean, where organisms survive off of chemosynthesis.
First evidence of life
The oldest fossils are from 3.5-3.8 GA
They were called Cyanobacteria
- They were prokayrotes (single cell)
Explain the Isua Formation
Is an Archean crustal belt in Greenland, it represents the most complete and largest belt of Archean crust in the world. It is date to 3.7-3.8 billion years old. It is the earthliest known stratigraphic part of earths history.
What do rocks from the Eoarchean lack
Fossils
How did Banded Iron Formations play into the development of life*** test question
iron remained in solution in the non-oxygenated environment of the earlier Archean Eon. In chemistry, this is known as a reducing environment. Once the environment was oxygenated, iron combined with free oxygen to form solid precipitates of iron oxide, such as the mineral hematite or magnetite. These precipitates accumulated into large mineral deposits with red chert known as banded-iron formations, which are dated at about 2 billion years.
Define GOE
Great Oxidation Event
Define Stomatolites
A fossil that forms as algal mats grow and capture sediment into mounds.
These first well-preserved fossils are photosynthetic microbial mats, called stromatolites, found in Australia.
Think “layered rock”
When did the first Eukaryotes appear
2 billion years ago,
Define Eukaryotes
A type of organism in with a cell or cells that contains a nucleus. The process of mitosis or splitting into identical daughter cells.
Define and explain the Ediacaran Biota
The instance or biome in the world that preserves the first multicellular life on earth
Explain the Cambrian Explosion
Part of the reason there is an explosion of life is because life can be preserved as in the Cambrian more organisms have shells. Small shelly fauna
Explain the Burgess Shale formation
massive site of preservation of soft bodied animals
very rare in the geologic record because
Life in the Paleozoic
Silurian and Devonian - age of the fishes