11. CAMBRIAN PERIOD
540 Million Years Ago
Erosion and Sedimentary Rocks, Oklahoma
Cambrian
Cambrian Explosion
3.75: SEDIMENTARY ROCKS - Sedimentary rocks don’t require water, but by far the majority of sedimentary rocks were transported and deposited in water. The oldest sedimentary rocks are the banded iron formations. Iron was released into shallow seas through submarine volcanics, iron was transported in solution to areas of shallow water where they were deposited.
OKLAHOMA
Following a brief period when newly formed Cambrian igneous rocks and ancient Precambrian rocks were partly eroded, shallow seas covered Oklahoma during the early Paleozoic Era. This began a long period of geologic time (515 million years) when parts of Oklahoma were alternately inundated by shallow seas and then raised above sea level. Many rocks that formed in the various sedimentary environments contain fossils and diverse mineral deposits.
Stromatolite Locations 3.5-3.8 Billion Years Old
SEE DEVONIAN FOR HOW THE NUMBER OF DAYS IN A YEAR CHANGES OVER TIME
Cambrian marks the beginning of the Paleozoic - Old Life, the first fossils - what is a fossil
End of Stromatolites 500 Ma (except you can find them present day)
mat of cyanobacterial filaments, collects fine sediment creating a framework for it to grow, creating a new layer each day. When the cyanobacteria die, they leave a structure of layered sediment, but none of the organic material is preserved.
First snails and other organisms show up to eat mats of cyanobacteria and algae, exposing the sea floor for new burrowing animals.