Earth and Space Science MCAS Review Earth and Space Science

Rocks and Minerals Rocks are groups of different minerals pushed together and combined. Mineral examples: Gold, silver, ruby, copper, granite, sulfur Think about granite countertops Piece of granite often has loads of quartz. It's ground up and crushed, but its still bits of quartz. Granite is a rock and quartz is a mineral.

Igneous Rocks The rocks that were superheated and originally liquid. they often start their lives below the crust and then get pumped out. There are two basic types of igneous rocks. rocks that make it to the surface (extrusive) Rocks that are stuck in the crust just below the surface (intrusive). These igneous types have all hardened after being molten rock. Volcano rocks

Metamorphic Rocks This rock type is created by heat and/or pressure Even though heat is involved, they didn't start off as molten rock. Some force (heat/pressure) has changed these rocks from one type into a new type. (METAMORPHIC) Found near volcanos and other hot areas Also found near fault lines where plates push against each other and create enormous pressures. examples are marble, jade, slate, and gneiss

Sedimentary Rocks Probably the rarest Sedimentary rock types are created when sediment compresses How do sedimentary rocks form? Water flows over continental land picks up a bunch of silt. Sediment and silt runs downstream and deposits where the river ends this happen over millions of years, more and more sediment builds up and compacts. sandstone, amber, anthracite, and limestone

Weathering Weathering is the breaking down or dissolving of rocks and minerals on Earths surface. Water, ice, acids, salt, plants, animals, and changes in temperature are all agents of weathering.

Erosion Once the rock has been broken down, a process called erosion transports the bits of rock and minerals away. No rock on Earths surface is hard enough to resist weathering. Together, the processes of weathering and erosion carved the Grand Canyon, in the U.S. state of Arizona.

Deposition Deposition is the geological process in which sediments, soil and rocks are added to a landform or land mass. Wind, ice, water, and gravity transport previously weathered surface material, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of sediment.

STOP: Nearpod Quiz Rocks Weather and erosion quiz

Fossils Fossils provide evidence on how the Earth has changed over time Remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock. Fossil is Latin for “obtained by digging” There are two main types of fossils; body and trace.

Fossils Body fossils include the remains of organisms that were once living (bones, shells, teeth, eggs, etc) Trace fossils are the signs that organisms were once present (footprints, tracks, burrow, coprolites). Trace fossils represent a data source that reflects animal behaviors. Many traces date from significantly earlier than the body fossils of the animals suspected to have made them.

Fossils Fossilization of an organism requires a unique set of circumstances so that it doesn’t just decay without a trace. These conditions include: 1. Rapid and permanent burial/entombment 2. Lack of oxygen that limits decay and scavenging. 3. Continued sediment accumulation 4. The absence of heat or compression which might destroy the fossil Fossils are most often preserved within sediments that were deposited in water, such as wetlands, river basins, or the ocean.

Types of Fossilization Per mineralization or Petrification: After an organism is buried, minerals carried by water such as silica, calcite or pyrite replace the organic material in the fossil. Some common examples are most dinosaur bones, petrified wood, and many trilobite fossils.

Types of Fossilization Molds and Casts - A mold fossil is when the organism decays leaving an impression in the rock called a mold. A cast is when that mold has been filled in with rock or minerals.

Types of Fossilization Carbonization - Carbonization is a process in which the more volatile substances of the organism (hydrogen, oxygen, nitrogen, etc) are removed, leaving behind the carbon. These fossils typically appear as a thin, dark film on the rock. This type of preservation is common among plant fossils.

Glaciers Glaciers also contain evidence of past history Organism have been preserved in a frozen state

History of Earth Earth is 4.5 billion years old. We know this by looking at the abundance of elements in really old rocks

History of Earth Paleontologists look at fossils to study organisms that lived in different time periods. Organisms have evolved over time

Stop nearpod Fossils and Earth's History

Gravity Gravity is a force which tries to pull two objects toward each other. Anything which has mass also has a gravitational pull. The more massive an object is, the stronger its gravitational pull is. Earth's gravity is what keeps you on the ground and what causes objects to fall.

Gravity and Formation Gravity plays a role in the formation of stars and planets  A star and its planets form out of a collapsing cloud of dust and gas within a larger cloud called a nebula.

Gravity in the Solar System Gravity creates stars and planets by pulling together the material from which they are made. Gravity is what holds the planets in orbit around the sun and what keeps the moon in orbit around Earth. The gravitational pull of the moon pulls the seas towards it, causing the ocean tides.

Gravity in the Solar System Gravity is very important to us. We could not live on Earth without it. The sun's gravity keeps Earth in orbit around it, keeping us at a comfortable distance to enjoy the sun's light and warmth. It holds down our atmosphere and the air we need to breath. Gravity is what holds our world together.

Gravity in the Solar System Newton’s law of gravity allows the planets and other objects to take only certain types of orbit.  These are circular, elliptical, parabolic or hyperbolic orbits.

STOP: NEAR POD QUIZ Gravity quiz NEARPOD.COM