Welcome to Catnapin's
Geologic Time Scale
This page is under construction. |
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Listed with the time scale are interesting events I found surfing the web. I like seeing the order.
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Geologic Time Scale Divisions are determined by geological or paleontological events, many are based on mass extinctions. see "Extinctions". Strata are described in Eon, Era, Period, Epoch, Stage, then by layers of geological series and formations. Major divisions are world wide. Most series and formations are regional. No place on Earth has layers of all the divisions. It is like a 3D mosaic. Because of regional discrepancy's in nomenclature, geologists often use Upper (Late), Middle, or Lower (Early). Why do dates of time periods change from list to list? When scientists first started studying astronomy, geologic layers and , they believed the Earth as the center of the universe, the world could not be more than a few thousand years old, and the continents were static. Universities were religious institutions, so knowledge was molded by religious traditions. Challenging religious concepts is very dangerous. A tremendous amount of data had to be collected and presented to change commonly held beliefs. Each generation's understanding is built on previous experiences and should not be ridiculed for what they did not know. The man who proposed a creation date of over 10,000 years was laughed at, but the evidence supported him. Now we believe the Earth is 4.6 billion years old and the universe is 11 to 20 billion. Each year, new studies refine our understanding. |
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Beginning of Time |
Then till now |
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Big Bang |
between 11.2 & 20 billion years ago |
The sudden existence of all matter and energy of our universe spreading out from a singularity. Everything was evenly spaced with a common temperature. Light was ubiquitous. |
|
1 second later |
First growth spurt of the universe, inflation factor of 1043. Formation of protons and neutrons as the universe expanded. |
|
3 minutes |
Formation of the first helium and lithium atoms. Then the end of Fusion. |
CMB |
380,000 years old |
The universe expands and cools enough to form neutral hydrogen. Formation of the Cosmic Microwave Background. |
Cosmic Dark Ages |
200 million years old |
Lasts about 1 billion years Neutral hydrogen naturally traps visible and UV light making the universe dark. This Dark Matter does not dissipate its own energy. (Even today, 80% of all the mater in the universe still consists of Dark Matter.) CMB currents clump together Dark Matter. When the mass of Dark Matter became larger than 1000 Suns then the mass was cool enough to let hydrogen clump. The expansion of the universe kept gravity from collapsing matter back into a singularity. Currents in the CBM created eddies that kept expansion from tearing matter apart. |
|
600 million years old |
Gravity pulled Normal Matter (baryons) together, to the center of Dark Matter clumps that were the size of small galaxies. More matter means more density. Enough density allows nuclear fusion and the first stars form. These stars were larger then any today. Heavy elements (created inside current stars), which dissipate heat efficiently, did not existed at this time. So these massive suns burned very hot, producing UV photons that ionized the hydrogen and unbound other Normal Matter 1000 light years around them. These first stars were more than 100 times larger than our sun. They may have become supernovas within 1 million years. That explosion would have formed a bubble of Normal Matter within the surrounding Dark Matter cluster (which astronomers still see around galaxies). Normal Matter clumps together to form more stars. If a star was over 300 times larger than our sun then it would have imploded to become a large black hole. The universe was still filled with neutral hydrogen so it still would have appeared dark to a human. |
Age of Re-ionization |
about 1 billion years old |
Enough mater pulls together to re-ionize the universe. This allows for visible light to be transmitted. |
Precambrian |
4.5 billion to 500 million years ago |
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Hadean Eon |
4.5 to 3.8 bya |
Our solar system forms, possibly from a supernova cloud. |
Archaean Eon |
3.8 to 2.5 bya |
Earth's crust cools and oldest terrestrial rocks form (3.8 bya) Atmosphere of methane and ammonia Oldest fossil at 3.5 billion ya is stromatolite |
Proterozoic Eon |
2.5 bya to 543 mya |
First true continents Abundant fossils of bacteria and archaeans eukaryotic cells are possibly 1.8 billion years old Atmospheric oxygen pollution from photosynthetic organisms like stromatolite - First mass extinction First "red bed" layers from iron oxide Llano uplift of Texas contains rocks from this age |
*Vendian Period |
650 to 543 mya |
First fossils of soft-bodied multi-cellular organisms Super-continent of Rodinia |
Phanerozoic Eon |
544 mya to today |
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Paleozoic Era |
543 to 248 mya |
|
*Cambrian Period |
543 to 490 mya |
Cambrian Explosion - in a few million years almost all known animal phyla appear and diversify Breakup of the super-continent of Rodinia The largest land mass is called proto-Gondwana No glaciation - mild climate |
*Ordovician Period |
490 to 443 mya |
Super-continent of Gondwana shifted to the southern hemisphere and much of it sunk underwater. mild climate. Algae, graptolites, trilobites, brachiopods, cephalopods, coral, crinoids, gastropods. First bone teeth in early vertebrates called conodonts Possible - first plants growing above water. Late Ordovician - massive glaciers drain shallow seas, and drop sea levels. Mass Extinctions - 60% of all marine invertebrate genera |
*Silurian Period |
443 to 417 mya |
Stabilization of climate, melting of the glaciers, rise in ocean levels Rapid spread of jawless fish First coral reefs, first freshwater fish, first jawed fish On land, relatives of spiders & centipedes First vascular plants |
*Devonian Period |
417 to 354 mya |
Two small continents and one large in southern hemisphere First forests of ferns, horsetails, seed plants, trees First tetrapods, first terrestrial arthropods and arachnids Many new fish appear. Mass Extinctions - 365 mya possibly volcanic - Russia/Asia Mass Extinctions - 354 mya possibly volcanic - Russia/Asia |
*Carboniferous Period |
354 to 290 mya |
Abundant swamps deposited material that became large coal beds across North America, Europe, and Asia. First amniotic egg Mild climate decreased club moss and large insects Increase in tree ferns |
**Mississippian Epoch |
360 to 325 mya |
in USA mostly limestone, crinoids, algae |
**Pennsylvanian Epoch |
325 to 290 mya |
in USA mostly coal climate with glaciers alternate land as terrestrial or marine Collision of Laurussia and Godwanaland produces the Appalachian Mountains, Hercynian Mountains of the UK, and the Ural Mountains of eastern Europe. |
*Permian Period |
290 to 248 mya |
Super-continent of Pangaea, super-ocean of Panthalassa, small sea called Tethys Interior of Pangaea was a seasonal desert, less glaciation First gymnosperms End of the Permian - largest mass extinction, mostly marine Mass Extinctions - 240 mya possibly volcanic - Russia/Asia Mass Extinctions - 248 mya possibly volcanic - Russia/Asia |
Mesozoic Era |
248 to 65 mya - "Age of Dinosaurs" |
|
*Triassic Period |
245 to 208 mya |
Modern gymnosperms First dinosaurs Mass Extinctions - 208 mya |
*Jurassic Period |
208 to 146 mya |
Dinosaurs grow huge First pterosaurs, first birds Huge marine reptiles, abundant cephalopods Break-up of Pangaea begins Gondwanaland split large trap splits Antarctica from South Africa Mass Extinctions - ? mya Mass Extinctions - ? mya Mass Extinctions - 146 mya |
*Cretaceous Period |
146 to 65 mya |
Middle Cretaceous First angiosperms - diversified quickly First Ceratopsians, First modern mammal and bird groups Massive volcano removes India from Africa and slams it into Asia forming the Himalayan Mountains Mass Extinctions - ? mya Mass Extinctions - ? mya Mass Extinctions - 65 mya Massive asteroid hits near Chicxulub and leaves a 300 mile wide crater in the Gulf of Mexico. Killed all non-avian dinosaurs, ammonites, marine reptiles |
Cenozoic Era |
65 mya to present - "Age of Mammals" |
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*Tertiary Period |
65 to 1.8 mya |
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**Paleocene Epoch |
65 to 54.8 mya |
Mass Extinctions - 54.8 mya |
**Eocene Epoch |
54.8 to 33.7 mya |
Oldest known fossils of many modern orders of mammals, early dear and horses were prevalent |
**Oligocene Epoch |
33.7 to 23.8 mya |
Cool climate First elephants with trunks First true horses Many new grasses Mass Extinctions - ? mya |
**Miocene Epoch |
23.8 to 5.3 mya |
Warm climate then cooler, dry continental interiors Antarctica becomes isolated and oceans do not mix so continent becomes covered with glaciers Africa/Arabic plates join Asia First kelp forests, First grasslands Mass Extinctions - ? mya |
**Pliocene Epoch |
5.3 to 1.8 mya |
Cooler climate, polar ice, Antarctic extinctions Land bridge between North & South America appears Grassy savannas with herds of grazers (mammal) on most continents Late Pliocene - ice ages |
*Quaternary Period |
1.8 mya to present |
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**Pleistocene Epoch |
1.8 mya to 11,000 ya |
dramatic climate change - Ice ages alternate with warmer periods but don't seem to have caused the extinctions Very large land mammals Mammoths, horse, camels First Homo sapiens - spread across most of the world and may have caused the mass extinction at the end of the Pleistocene |
**Holocene Epoch |
11,000 ya to present |
Time between the last ice age and now. Generally warm climate except for "mini-ice age" "Age of Man" - all of recorded history |
Time Line uses dates and information from www.ucmp.berkeley.edu
Dark Matter: the unknown stuff that fills 70-80% of the mass of the universe. Astronomers believe it is the cause of the increasing expansion of the universe. It may be space itself (Einstein's "cosmological constant"), something that fills in the void like a fog, or the result of a breakdown in our knowledge of gravity when observing huge distances.
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