Geological Eras-Camila Carrillo

Nota:

• Covers almost 4,000 milions years. Is the formation of the lithosphere, the ocean and the almosphere.

Nota:

• Spans 560 million years, has three eras and reaches the present time, the Holocene.

Nota:

• Era spanned 312 millions years and is when the Earth was divided into several continents.

1. Cambrian

   Nota:

   • It lasted for about 13 – 25 million years and animal fossils began to appear.
   1. Ordovician

      Nota:

      • Lasted almost 45 million years and in this period, the area north of the tropics was almost entirely ocean, and most of the world's land was collected into the southern supercontinent Gondwana.
      1. Silurian

         Nota:

         • The sea was leveling out which generated rivers, ecosystems, etc.
         1. Devonian

            Nota:

            • It was a time when extensive reefs were built in the shallow waters that surrounded each continent and separated Gondwana from Euramerica.
            1. Mississippian

               Nota:

               • Shallow, low-latitude seas and lush terrestrial swamps covered the interior of the North American continent.
               1. Pennsylvanian

                  Nota:

                  • The spreading swamps established the thick beds of dead plant material that today make up most of the world's coal.
                  1. Permian

                     Nota:

                     • Pangaea presented severe extremes of climate and environment due to its vast size and which ended in the largest mass extinction the Earth has ever known.

Nota:

• The era for the dinosaurs, plant life and the continents are getting closer to their current appearance.

1. Cretaseous

   Nota:

   • 65 million years ago, an asteroid collided with Earth in Mexico's Yucatán Peninsula, forming what is now called the Chicxulub impact crater.
   1. Jurassic

      Nota:

      • The supercontinent Pangea broke up and dinosaurs kept appearing.
      1. Triassic

         Nota:

         • It was a desolate time in Earth's history, violent volcanic eruptions, climate change, a fatal encounter with a comet or asteroid that had caused the extinction of more than 90% of Earth's species.

Nota:

• Era formed the Andes (movement of the Nazca plate, below the South American plate).

Nota:

• Spands the last 65 millions years, up to the present day. Collision of Asia with India and Arabia with Euracia. Dinosaurians disappear and current human begin appears.

1. Paleocene

   Nota:

   • It began with the mass extinction event at the end of the Cretaceous, the disappearance of dinosaurs, not birds, giant marine reptiles, and much fauna and flora.
   1. Eocene

      Nota:

      • The warmest period during the Cenozoic, marked the decline into an icy climate and the rapid expansion of the Antarctic ice sheet.
      1. Oligocene

         Nota:

         • It is the third and last epoch of the Paleogene. Global expansion of grasslands and a regression of tropical broadleaf forests to the equatorial belt.
         1. Miocene

            Nota:

            • Time of warmer global climates and appearance of: kelp forests and grasslands.
            1. Pliocene

               Nota:

               • The tectonic plates of India and Asia collided, forming the Himalayas. In North America, waterfalls rose, the Rocky Mountains rose, and there was activity in the mountains of Alaska and the Great Basin mountain ranges of Nevada and Utah.
               1. Pleistocene

                  Nota:

                  • It began about 2.6 million years ago. The Ice Age where glaciers formed that covered large parts of planet Earth.
                  1. Holocene

                     Nota:

                     • It began 12,000 to 11,500 years ago. When the Earth entered a warming trend, the glaciers retreated. The tundra gave way to the forest.