Review

This map shows the age of the crust that makes up the continents and
ocean islands.
A Slice through the Earth’s Surface
The model hanging above you shows that the Earth’s crust is just a thin
veneer lying on top of the mantle. The lighter rocks of the continental
crust float higher on the mantle than the denser rocks of the oceanic
crust. The relief of the Earth’s surface - the difference between the
deep ocean basins and the high continents - is caused by this difference
in density.
MID-ATLANTIC RIDGE PILLOW BASALT
This example illustrates how pillow basalts grow. First, a pillow structure
forms, then increasing magmatic pressure fractures part of the
surface. Lava is squeezed through the jagged fracture like toothpaste,
forming a striated pillow tube.
Provided by Prof Charles Langmuir
Lamont-Doherty Earth Observatory
Columbia University, New York, New York
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An important synthesis was published in a 1968 paper, “Seismology
and the New Global Tectonics,” by the geophysicists Bryan Isacks, Jack
Oliver, and Lynn Sykes.
Donated by the Dofasco Company, Strathy Township, Ontario,
Canada
The white dot on the Moon model to your left indicates the collection
site of this sample, between Mare Imbrium and Mare Serenitatis. The
panoramic photo to your right depicts the Lunar Rover on the Moon’s
surface, with David Scott setting out on foot.
From the project FULL MOON by Michael Light, 1999
The Museum also gratefully acknowledges major funding from the
Charles Hayden Foundation. Presented with special thanks to NASA
and the National Science Foundation.
Revive