Forces that Attack the Surface
Which force erodes the earth the most?
Water
What are some examples of early evidence of a round earth?
Ships
Eclipse
A mountain building event is called a/an
orogeny
what is the weak lower section of the mantle called?
asthenosphere
half of a great circle is a line of...
Longitude
Name and describe 4 layers of earth
Crust - thin, rigid rock
Mantle - slowly flowing material, magnesium/silicon
Outer core - liquid iron/nickel
Inner core - solid iron/nickel rotates faster than rest of earth
How is relative time used?
how do we know about earth's internal structure?
indirect observation
a mountain building event is called
an orogeny
Most sediments are carried in a river in this way
Suspension
What does the law of cross cutting state?
Any geologic feature that crosscuts or modifies another feature must be younger than the rocks it cuts through
Name and describe the index fossil from the PreCambrian era
Stromatalites
layered algae structures
What unique aspect of earth is the outer core responsible for?
magnetosphere
after 2 half-lives, what percent of the original material would still be radioactive?
25%
What 2 factors affect porosity?
Shape and sorting
What is a benchmark in topography?
Point on a map that the latitude, longitude, and elevation is precisely calculated
What are the two periods in the Cenozoic era?
Quaternary
Tertiary
What is unique about the inner core in relation to all other parts of earth?
rotates faster than the rest o f earth
Most of earth's history is known as ________________ time.
Precambrian
What 2 factors determine carrying power of a stream?
Speed and discharge
Define foliation
sheet-like or banded structure of rocks caused by alignment of grains due to pressure and heat
How many periods are in the Paleozoic era?
7
Permian, Pennsylvanian, Mississippian, Devonian, Silurian, Ordivician, Cambrian
List and describe the 4 layers of earth
crust - thin, rigid rock
mantle - slowly flowing material
outer core - liquid iron and nickel
inner core - solid iron and nickel
The colour of a star tells you its
temperature