Name____________________
How the Earth Was Made (Part 2)
The History Channel, 2007
Granite Planet
1) The oldest continental rock on Earth can be found in South Africa…it is ancient __________________ which
is the nucleus of one of the world’s oldest continents.
2) 3.5 million years ago, _______________ was appearing everywhere because of an upsurge in volcanism.
Granite is the first true ___________________ _________.
3) Granite rock has a much lower __________ than basaltic rocks which are found on the bottom of the ocean.
The continents that are light and buoyant ___________ on the mantle.
4) The granite crust was also tough enough to withstand the erosive power of the ________________.
5) On the continental coast an organism appeared that was going to transform
the planet: the __________________ which could live off of
_________________ and fill the atmosphere with ____________________.
6) ______________________ can be found today on the Western Australian
coast in Shark Bay. They are ____ foot wide and _____ feet high mounds
made by bacterial algae that precipitate ________. They are the ancestors of
all _______ on Earth.
7) 2.5 billion years ago, __________________were blossoming globally and
filling the atmosphere with oxygen through _________________. This
happened over a period of _____ billion years. At first the gas dissolved in the
water in the oceans and ______________ out the iron. Then it began to build
up in the _____________________ and diluted the ____________ ________________ which cleared the air.
8) When the iron left the oceans they turned from _____________ to _______________. When the oxygen
filled the sky, they turned _____________ as well resulting in the __________ planet.
9) The iron accumulated on the floors of the ocean is the source of all the iron ________________ mined
today.
10) Plate Tectonics is the study of __________________ ___________________. Historically it was believed
that the continents were fixed in place and never moved. However there was a problem in the fossil record.
The fresh water Paradoxides trilobite ___________ was found on both the east coast of North America and on
the western coast of Britain.
11) Alfred Wegener, a German weather scientist, boldly claimed that the continents had once been
____________ together, but had ____________apart. Because he was a meteorologist, and not a geologist
most people rejected his ideas. He died in Greenland, in 1930, lost in a ________________.
12) The US Navy produced a global map of the __________ _________ during World War II and revealed one
of Earth’s greatest secrets. The maps revealed a fractured network of submarine _____________, volcanic
________ and ____________ that split the oceans into enormous __________ of ____________.
13) Plate Tectonics is driven by the ___________________ of the old and the _______________ of the new.
14) Draw a convection current within the mantle here:
15) Where the currents rise, _________ form creating new ______________ crust within the gap. Where the
currents sink back down towards the center of the Earth, old ____________ crust is dragged down with them
in a continuous cycle. The oceanic plates drag the __________________ like a conveyor belt.
16) The process of ocean crust creation is present above the water in _________________. Iceland is on a
mid-Atlantic ridge.
17) Fissure eruptions are ___________________________ and appear on Iceland. They mark the path of the
plate boundaries scaring the rocky landscape with shallow canyons that are very slowly widening Iceland and
creating the ____________ ocean. At their base is _____________ crust slowly pushing ___________ and
________________ apart.
18) The rate of continental drift averages _________ cm/year (one inch). Over millions of years, this speed of
movement is enough to shift the continents ________________ of miles.
19) The movements of the continents can be tracked back a _________________ years.
20) The supercontinent called ________________ was lifeless and barren. North America and ____________
made up its core.