Earth's Structure
This is the outermost layer of earth's layers
Crust or lithosphere
What is the decayed remains of once-living creatures?
Humus
How has most of earth's sediments been laid down?
By moving water.
Define a fossil.
The preserved remains of once-living organisms.
Geologist study history of earth's physical structures. What do paleontologists study?
History as revealed in the preserved remains of once-living organisms (fossils).
This is the very bottom of the earth's crust.
The Mojo.
Besides humus, what else is soil composed of? Name 3.
Gravel, sand, silt and clay.
What is the area where 2 tectonic plates meet called?
A fault (not my fault!)
Explain the mold/cast formation of fossils.
A shell or animal decays completely leaving a mold. The mold fills in with sedimentary rock called a cast which is the fossil.
Which view requires more time for the processes of rock formation?
Uniformitarianism
Which layer has the consistency of corn starch mixed with water?
The mantle.
Of the 3 types of rocks, which type is most commonly found on the surface of the Earth?
Sedimentary.
Show with your hands or 2 books how a fault-block mountain is formed.
2 plates move together, one moves down and the other moves up forming a mountain.
Explain what petrification is.
Water and minerals flow around the decaying animal and minerals fill in the pores. The minerals harden and form a rock in the shape of the animal or material.
Which view believes that the geology we see today is the result of processes that occured once in Earth's past and will not be repeated.
Catastrophic perspective.
This theory states that earth's crust is broken up into plates which float around on plastic rock.
Plate tectonics.
What is a mineral?
It is a crystalline substance that is the same material throughout. It's chemical makeup does not change in the sample.
Name a type of physical weathering and a type of chemical weathering.
Physical- ice, temperature changes, abrasion from sand or running water.
Chemical- minerals in rock chemically react with the air or water changing their makeup , such as acid rain.
What type of rock are most fossils found in?
Sedimentary.
What are index fossils?
Fossils that are assumed to represent a certain time period in Earth's past.
What 2 metals is the inner core made of?
Solid iron and nickel.
What features do crystalline substances have?
Sharp, geometric shapes, flat surfaces or faces and well-defined edges.
What did Experiment 6.2 show us about how water affects sediment?
Water has the ability to separate into layers, called deposition, denser material on the bottom and less dense at the top.
What type of organism are most fossils of?
Hard-shelled organisms like clams.
What can you not find in the geologic column ?
All layers of the geologic column with their index fossils.