Points:
/50
Chapter 5: Using Igneous Rocks to Interpret Earth History
Exercise 5.3
(14 points)
(a) i
The crust
(1 pt)
(a)
ii The crust will cool faster because of its greater surface area, so more of the hot material
is in contact with the cold environment
.
(2 pt)
(a) iii
Circle answers: (
faster
, slower), (
larger
, smaller)
(2 pt)
(b) I
The coffee in the plastic cup is going to cool faster. Styrofoam is a poor heat conductor.
You can’t hold a plastic cup of a hot liquid without burning your fingers, but you can easily hold
a Styrofoam cup of hot liquid because it is a better insulator.
(3 pt)
(b) ii
Circle answer: (
faster
, slower)
(1 pt)
(d) i
Circle answer: (
finer
, coarser)
(1 pt)
ii
Circle answer: (finer,
coarser
)
(1 pt)
iii
aphanitic rock
(1 pt)
iv
pegmatitic and phaneritic rocks
(2 pt)
Exercise 5.7
(36 points)
Identify all of the samples listed below. Fill in the chart on the next
page. Hand in the chart along with the lab answer sheet.
*** You do not need to fill out the last column in the chart.
Sample #s: 1, 2, 4, 6, 8-10, 12, 14.
Basalt
Granite Pegmatite
Porphyritic Andesite
Gabbro
Obsidian
Porphyritic Basalt
Granite
Rhyolite
Pumice
