Earth’s Structure
What are the three main layers of Earth?
The crust, the mantle and the core.
Who first figured out that Earth’s continents are on the move?
Alfred Wegener
What are the three main kinds of rocks?
Igneous, metamorphic, and sedimentary.
What is a mineral?
Minerals are:
-Naturally occurring
-Inorganic
-Solid
-Ordered internal structure
-Definite chemical composition
Where and what is the significance of “fall line” in Arkansas?
Interior highlands and gulf coastal plain, separates the state making it’s geology very diverse.
What characteristics describe the crust?
Thin, least dense, everything lives on it
What do we mean by plate tectonics?
The theory that Earth’s crust is separated into 20 parts that are connected, move, and create energy.
How do igneous rocks form?
Hot molten rock (lava) solidifies and crystalizes
How is a mineral different from a rock?
Minerals are made of more elements and compounds, it reminds me of a rock just at a smaller scale, like atoms to humans. Also, rocks can include organic remains, such as fossils, but minerals can’t. Lastly, rocks make up the solid crust of the Earth, while minerals make up the rocks, sands, and components of soils. So rocks are the base, and minerals are everything on top.
What are the five physiographic provinces of Arkansas and how do they differ from one another?
Ozark Plateau:Plateaus, caves, caverns, and sinks
Arkansas River Valley:Isolated, flat-topped, steep-sided mesas
Ouachita Mountains: They run east to west, rather than the north to south. The sandstone and shale slopes harbor two types of forest.
Mississippi River Alluvial Plain: Extremely flat surface; soils, poor drainage, wetland; widely scattered forests, farms.
West Gulf Coastal Plain: Extensive areas of forests; level to rolling terrain;
What characteristics describe the mantle?
Mantle: Makes up a big part of the earth's interior.
Upper mantle, where plate tectonics are.
Transition zone, rocks become more dense, they don’t melt
Lower mantle, softens rocks.
What kind of evidence supports plate tectonics theory?
Earthquakes only forming in specific places, alternating magnetic properties, South America and Africa looking like they would fit together.
How do metamorphic rocks form?
A rock is subjected to high heat or pressure and the rock changes.
Why are minerals useful to us?
-Calcium builds bones, activates enzymes, regulates blood pressure, helps muscles to contract, nerves to send messages, and blood to clot.
-Magnesium builds bones, regulates blood pressure and sugar, enables muscles to contract, nerves send messages, blood to clot, and enzymes to work.
-Potassium balances fluids in the body, maintain steady heartbeat and muscles contracting, may benefit bones and blood pressure.
Basically, our body needs specific minerals so we can thrive. They do things like keeping your bones, muscles, heart, brain working properly and making enzymes and hormones.
How do differences between the physiographic provinces affect the ecology (plants and animals) and human geography of each area?
Place in Interior highlands: Mountains, caves and karsts. Different species live here because of the caves. Dense forestation.
Places in Gulf coastal plain: Flat land, lots of farms and agriculture, widely spread forests.
What characteristics describe the core?
Very hot, very dense, center of the Earth.
Outer core, made of liquid iron and nickel.
Inner core, hot, dense, solid, mostly iron.
Why are volcanoes and earthquakes more common at plate boundaries?
Because it’s where the plates meet, and hit each other. Which makes pressure and energy that needs somewhere to go, so eventually it releases the pressure upwards, creating a volcano or colliding and making an earthquake.
How do sedimentary rocks form?
Pieces of rock are loosened by weathering and that sediment is compacted together in layers.
Which kinds of rock are common in Arkansas? Which are rare?
Sedimentary rocks are very common. There are a few igneous rocks and some very low-grade metamorphic rocks, but these occupy little area.
How does density play a role in the layers of the Earth?
Crust: Least dense, most solid
Mantle: In the middle, where the density starts to gradually get higher
Core: The outer core is so dense it’s pretty much made of molten metal. But the inner core is so dense and is above the melting point of iron.
Basically, different density changes the form of the layers because of the distance from the core.
What are the three different types of plate boundaries?
Divergent, convergent, and transform
What do we mean by the rock cycle?
The cycle in which rocks are broken down and reformed into new rocks.