Barron's: The Leader in Test Preparation 7th Edition

AP Environmental Science 

__________________________________________________________________________________________

Unit 1 : Earth Systems and Resources 

1: The Earth -Geologic Time Scale

• Time is divided up into eons, eras, periods, epochs, and stages (greatest to least).

• Layers of rock, called strata, are spread out to represent different parts of time. Strata can look entirely different depending on what time and area it's laid down upon. It can appear eroded, tilted, or inverted once it's deposed. 

• The Principle of Superposition says that any layer is most likely older than layers above it, but younger than those below it.

• Procaryotes are organisms without a membrane-bound nucleus in its cells.

• The Cenozoic era was separated into the Neogene and Paleogene period. The Neogene period gave rise to civilizations, while the Paleogene was when man first appeared. With the existence of man, came more mammals, birds, and insects.

            -Herbs and grass prospered, as well as flowering plants. 

            -The ice age occurred during this era.

• The Mesozoic era consisted of the Cretaceous, Jurassic, and Triassic period. This was the age of the dinosaurs and birds, and flowering plants inhabited the land.

             -The Rocky Mountains began building in this era. 

• The Paleozoic era included the Permian, Carboniferous, Devonian, Silurian, Ordovician, and Cambrian periods. 

              -The Permian period showed a grater population of reptiles. 

              -The Carboniferous period was the age of amphibians. 

              -The Devonian period was the age of more fish.

              -The Silurian period showed a greater invasion of invertebrates on land. 

              -The Ordovician period exhibited the first vertebrates.

              -The Cambrian period had a lot of marine invertebrates. 

              -The Appalachian Mountains began building in this era. 

Earth's Structure 

• Earth is divided into the biosphere, hydrosphere, and the internal structure. 
• The biosphere is all forms of life on Earth, on land and sea. This includes all plants and animals.
• The hydrosphere is all forms of water on Earth. This includes freshwater, saltwater, snow, and ice. 
• The internal structure is divided further into different layers: the crust, mantle, and core. 

                 -Crust: 0.5% of Earth's mass; divided into the basalt-rich oceanic crust and granite-rich continental crust. The crust is on top of the middle of Earth, or its mantle. It's rocky, brittle, and cold. 

                 -Continental Crust: extends 20-30 miles down into Earth; less dense than the oceanic crust. It contains volcanic, sedimentary, granite, and metamorphic rocks. 

                -Oceanic Crust: thin piece of Earth's crust that lies under the ocean basins, containing basaltic rocks with sediments over it. 

                -Mantle: a solid layer that contains most of Earth's mass; 1,800˚F (1,000˚C); composed of iron, magnesium, aluminum, and silicon-oxygen compounds. 

                -Lithosphere: a solid outer layer of Earth that's "apart of the brittle upper section of the mantle and the crust." It breaks down into tectonic plates, where heat from the mantle cause it to move and slide against one another. Plate tectonics is a term used to describe the movement of tectonic plates and can cause earthquakes, and volcanoes from two plates rubbing together. 

               -Core: contains mostly iron with a molten outer core and cold inner core. 

Rocks

• Basalt- igneous, or volcanic, rock that forms from the cooling of lava. It can be found on the ocean floor and is the most common form of lava. 
• Granite- made up of quartz and feldspar that got crystallized from magma cooling below the Earth's surface.
• Metamorphic Rock- is morphed by extreme heat and pressure. ex. marble
• Sedimentary Rock- forms from deposition and solidification of sediment that gets transported by water, ice, and wind.
• Volcanic rock- forms from magma that erupts from an active volcano. 

Plate Tectonics 

• The Place Tectonic theory indicates that Earth's lithosphere is split into small numbers of plates that float and travel over the mantle.
• The Continental Drift Theory was proposed by Alfred Wegener in 1915