APES Flashcards
how long ago did the Earth form?
4.6 billion years ago
two time scales to measure the age of earth
the sequence of layering in rocks & natural radioactivity of chemical elements in rocks
strata def.
layer
info: rock layers laid down with each strata represents a “slice” of time
-
any layer is (younger/older) than those above it, (younger/older) than those below it
older, younger
superposition
any layer is older than those above it, younger than those below it
complications of measuring the age of earth using sequence of layering in rocks
eroded/distorted rock layers laid in different areas look different
at 4.5 billion years on the geological time scale, what happened
earth cools
at 3.5 billion years on the geological time scale, what happened
procaryotes exist
procaryotes
organisms whose cell lacks a nucleus
at 1.5 billion years on the geological time scale, what happened
eucaryotes
eucaryotes
organisms whose cells contain a nucleus
at 700 million years on the geological time scale, what happened
sea is formed
at 400 million years on the geological time scale, what happened
land is formed
biosphere
all forms of life
hydrosphere
all forms of water
internal structure
crust, mantle, core
the crust floats on top of ______
the mantle
two types of crusts
continental crust
oceanic crust
the continental crust is (less/more) dense than the oceanic crust
explain why
less dense than oceanic crust bc the oceanic crust is rich in heavier minerals
moho
boundary between Earth’s crust & mantle
layers of the earth in order from top to bottom
crust
(moho)
mantle
-lithosphere
-asthenosphere
core
most of earth’s mass is in which layer of the earth
mantle
what is the mantle composed of
iron, magnesium, aluminum, silicon-oxygen compounds
most of the mantle is (solid/liquid), except for the asthenosphere which is ______-like
solid
plastic-like
lithosphere
upper portion of the mantle & crust, composed of tectonic plates
which layer holds tectonic plates
lithosphere
lithosphere is a part of which two layers of the earth
upper mantle & crust
asthenosphere
part of the mantle under the lithosphere
what layer is under the lithosphere
asthenosphere
the core is mostly _____
iron
the outer core is _____, and the inner core is _____
molten, solid
the inner core is (solid/liquid)
solid
continental drift theory
theory by Alfred widener about Pangea drift based on six factors
-tropical plants discovered in Greenland, glaciated landscapes in Africa & South America, tropical regions had polar climates in the past, continents fit like a puzzle, similarities In rocks between north & South America & Africa, fossils of extinct land animals found on separate continents
who theorized the continental drift theory
Alfred wegener
six factors of the continental drift theory
-tropical plants discovered in Greenland
-glaciated landscapes in Africa & South America
-tropical regions had polar climates in the past
-continents fit like a puzzle
-similarities In rocks between north & South America, Africa
-fossils of extinct land animals found on separate continents
seafloor spreading theory
new crust is being made at volcanic rift zones due to rocks being older as they move away from the ridge
subduction zone
where two tectonic plates meet & move toward each other with one sliding underneath the other & moving down to the mantle
transform boundaries
where plates slide past each other, earthquakes, San Andreas fault
the San Andreas fault is an example of what type of boundary
transform boundary
what natural occurrence happens at transform boundaries
earthquakes
divergent boundaries
where plates slide apart, space created fills with molten magma, create oceanic massive fault zones & oceanic earthquakes.
what boundaries creates oceanic massive falult zones
divergent boundaries
the Mid-Atlantic Ridge is an example of what type of boundary
Oceanic divergent boundary
the African Great Rift Valley is an example of what type of boundary
Continental divergent boundary
the East Pacific Ridge is an example of what type of boundary
oceanic divergent boundary
convergent boundaries
where plates slide toward each other
subduction zones occur at what type of boundary
convergent boundaries
orogonic zone
when two plates collide and compress
what type of plate boundary occurs at the orogonic zone
convergent boundaries
what happens when a denser oceanic plate moves underneath a less dense continental plate
an oceanic trench is produced on the ocean side & a mountain range is produced on the continental side
the cascade mountain range is an example of what
convergent boundaries where an oceanic trench is produced on the ocean side & a mountain range is produced on the continental side
two ocean plates converging create …
an island arc
