Chapter 12-Earth's Internal Structure Flashcards
What are Earth’s main layers?
Crust, mantle, outer and inner crust
Where is the crust in relation to the other layers?
Top
How does the crust interact with the asthenosphere?
Floats on top of it while pushing it down
What is continental crust?
Thick but not dense
What is oceanic crust?
Thin but dense
Approximately how much of Earth’s mass is comprised of crustal
material?
0.4%
Where is the mantle in relation to the other layers?
Second highest layer
Approximately how much of Earth’s volume is comprised of the mantle?
84%
Where is the outer core in relation to the other layers?
Third highest layer, under mantle
Where is the outer core in relation to the other layers?
Liquid
Where is the outer core in relation to the other layers?
Lowest
How is the inner core similar to the outer core?
Same temperature and composition
What elements are most common in Earth’s crust?
Oxygen and silicon
How are igneous rocks formed?
Liquid rock cooled and solidified
What is the difference between lava and magma?
Magam is in crust, lava is on top of it
What are 2 characteristics used to classify igneous rocks?
Mineral composition and texture
What are extrusive igneous rocks?
Cooled above the surface
What are some characteristics of
extrusive igneous rocks?
Cools quickly; little time for crystal formation
What are intrusive igneous rocks?
cooled below the
surface (in the crust)
What are some characteristics of
intrusive igneous rocks?
May cool more slowly; more time for crystals to grow in liquid magma before solidifying
How does cooling time impact texture?
Crystals are bigger the slower they cool
How are sedimentary rocks formed?
deposition and lithification of small
fragments or dissolved substances from
other rocks or, in some cases, marine
animals.
What are the 3 major types of sedimentary rocks?
Limestone, sandstone, shale
How are metamorphic rocks formed?
Existed rocks that are
modified by heat and
pressure
What is contact metamorphism?
rock contacts magma and is rearranged
What is the most recent era, period, and epoch?
Cenozoic, Quatemary, Holocene
Where does much of our rock record fall on the geologic timescale?
Paleozoic
Other than radiometric dating, how else can we know how old certain rocks are?
Looking at landforms
What is “the Anthropocene”?
A new epoch in the
geological timescale based on the
recognition that humans are now the
foremost agent of change on the
Earth’s surface
