Earth

Earth

1. Fossils

   • Fossils
     • Traces of once living things preserved in rocks.
   • Paleontologists
     • They're scientists who study early life forms.
   • Strata
     • Layers of sediment that have formed over billions of years.
   • Geologic Time Scale
     • A scale showing the various eras (time periods) of Earth.
   • Cenozoic Era
     • This era was 65 million years ago to right now. This era brought the appearance of many modern species, first human like species (2-3 million years ago), and many other things happen.
   • Precambrian Era
     • The era 4600 million to 600 million years ago. This is when the earth formed, the first organism was created, and the first animals without a vertebrae were made.
   • Paleozoic Era
     • This era was 600 to 225 million years ago. This is the time first reptiles, large land animals, and various other things were created.
   • Mesozoic Era
     • This era was 225 to 65 million years ago. During this era dinosaurs become extinct, first birds and mammals are made and many other things happen.

2. Model of Earth

   • Model
     • Idea of something that can't be fully seen or known. It's a way of showing the object that's either smaller, or bigger than the actual version.
   • Mantle
     • About 2900 km thick. The upper part of the mantle is solid alike the crust. The mantle and crust combine to make a layer known as the 'llithosphere'.
   • Outer Core
     • The temperature in this area is so high that this part of the earth is liquid. This layer's about 2200 km thick.
   • Crust
     • Earth's outer layer. Everything we see around us is built on or is part of the core. It is 10-90 km sick.
   • Inner Core
     • This layer of the earth is solid although of the high temperature. All the other layers being pressed onto it make it a hard ball. It is 1250 km thick.
   • Earthquake
     • Trembling or vibration of the ground caused by the release of pressure building up in the earth's core.
   • Volcano
     •    Opening in Earth's crust through which solid and molten rock, ash and gases escape.  

3. Rocks/Minerals

   • Lustre
     • The way the light shines off of the surface of a rock or mineral.
   • Colour
     • The colour of the rock or mineral.
   • Streak
     • The colour of the poweder left behind when the rock mineral is scratched.
   • Hardness
     • The hardness of the rock or mineral on the Moh's Scale of Hardness. This is a scale measuring how hard a rock or mineral is.
   • Igneous Rock Type
     • Rock type made by magma being cooled down.
   • Metamorphic Rock Type
     • Rock type made by heat and pressure.
   • Sedimentary Rock Type
     • Rock type made by sediments being layed down on top of eachother.
   • Lava
     • When molten rock flows out of a volcano.

4. Mountains

   • Theory of Plate Tectonics
     • According to this theory, the lithosphere is broken up into many pieces known as 'Plates' which move in all directions.
   • Continental Drift
     • A theory made by the German scientist Alfred Wegener in 1910. This theory proposes that all continents were one big continent known as Pangaea, but they're always slowly moving away in many different directions.
   • Diverging Boundary
     • This is when two of Earth's plates are moving apart.
   • Boundary
     • The place where plates meet.
   • Transform Boundary
     • In this type of boundary, the plates slide past each other.
   • Converging Boundary
     • This is when the plates are slowly moving towards each other.
   • Subduction
     • This is when two plates combine, but one is heavier than the other. The heavier one goes under the lighter one and sometimes forms mountains.