Do Now – 5 Minutes Topic – Geologic Time Scale Presentations – Day 3 of 3 • If you did not turn in your food permission slip yesterday, or your Geologic Time Scale Lab, take them out to be collected. • Otherwise, take out your presentation assignment. • Neogene Period – please prepare to present Homework Geologic Time Scale Lab (2 Days late) Food permission slip (1 Day late) Turn in the Ebola Outbreak Article (5 Days Late) Turn in your Planetary Neighbors Worksheet (3 Days Late) Geologic Time Scale Project (Presentations begin TODAY) Send Me your Presentations! Larry and Harvard Permian Period Ordovician Period Received its name from the name of the rocks that formed during that period. Ordovician rocks are distinct from other rocks because they occur at the highest elevations on Earth – such as Mt. Everest Ordovician Period occurred 488.3 Mya – 443.7 Mya (about 45 million years) Ordovician Period Most of Earth’s continents were gathered in Gondwana (Africa, South America, Antarctica and Australia) – in the Southern Hemisphere. A few others made up the smaller continent of Laurentia (North America) Ordovician Period During this time, Earth was very warm and wet, and ocean levels rose as high as 1,970 ft. above where they are today. However, once Gondwana reached the South Pole, massive glaciers formed over Gondwana’s center, which shrank the ocean levels, causing a lot of marine life to die off during a 20 Million year-long ice age. Ordovician Period The atmosphere was rich in CO2 as compared to now (14 – 16 times higher), due to a high amount of volcanic activity. As a result, the world warmed and many storms formed. However, as previously mentioned, once Gondwana reached the South Pole, CO2 draw down occurred, which decreased the temperature of the world. Ordovician Period The Ordovician Period was rich with marine life. Such creatures were… Ordovician Period Trilobites Ordovician Period Conodonts Ordovician Period Cephalopods Ordovician Period Gastropods Ordovician Period Corals Ordovician Period Horseshoe Crabs Ordovician Period In terms of plants, there were many forms of Sponges Ordovician Period And… Algae Ordovician Period There is also evidence that land plants began to make their way to the shores during the Ordovician Period. Ordovician Period However, due to the change in temperature and formation of glaciers, the second-largest extinction event occurred on Earth: a 20-million year-long ice age occurred. 60% of all marine invertebrate life went extinct and 25% of all biological families perished towards the end of the Ordovician Period. Aquatic reefs collapsed and ocean levels became more shallow as ice began to form – making it difficult for the shallow water- dwelling creates to survive. Silurian Period The great extinction event that took place at the end of the Ordovician period marks the beginning of the Silurian Period. The Silurian Period gets its name from a section of rock strata that were studied in Wales. A British geologist named Sir Roderick Impey Murchison named the period of rocks after the Silures – a Celtic tribe in Wales. However Silures did not inhabit the land where Silurian rock was – he just named it after that. Silurian Period The Silurian Period started 443.7 Mya and ended 416.0 Mya (27.7 Million years) During this period of time, the large glacial formations that were created during the Ordovician period melted, which caused a rise in ocean levels. The climate began to stabilize during this period of time, giving life a chance to flourish. Silurian Period During this time, Gondwana traveled further towards the south pole of the Earth. Silurian Period Siberia, Baltica, and Laurentia were more located around the equator. Silurian Period At the end of the Silurian Period, Baltica and Laurentia collided, which formed a new supercontinent: Euramerica. Silurian Period With the warming of the planet came a period where greenhouse gases formed. These gases warmed the planet to points even warmer than the Ordovician and Devonian eras. As a result, freshwater formations began to occur, so aquatic life was not restricted to living in the ocean. Silurian Period Not all animals from the Ordovician Period went extinct – some of our old friends survived. Silurian Period Coral reefs, during the Silurian Period, thrived in Earth’s new climate. Silurian Period The Silurian Period also marked the first time freshwater fish and fish with jaws existed. Silurian Period During this time the first aquatic animals began to transition living on the land. Relatives of centipedes and spiders were some of the first creatures to live on land. Silurian Period Some of the first plants with a vascular system began to evolve during this time period as well. These plants lacked leaves, but plants could now begin to grow larger and outside of the ocean. Cooksonia Silurian Period Another example is from the baragwanthia plant. Silurian Period Not too many major geological events happened on Earth during this time. Most notably and substantially was the collision of Baltica and Laurentia, which created the mountain ranges that exist in North America and Northern Europe. Geologic Time Scale Quiz Mr. S and I will now pass out a quiz for you to take regarding all of the notes you took. This is an open-note quiz . You have until the end of the class to finish the quiz..