Science Ch. 5

The youngest rocks on the ocean floor are located ___

The crust and upper mantle make up Earth's ___

Scientists have observed that the plates move at rates ranging from 1 cm to 12 cm per ___

Plates of the lithosphere float on the ___

The result of plate movement can be seen at ___

The ___ are mountains formed by the collision of the Indo-Austrailian Plate and the Eurasian Plate.

The presence of the same ___ on several continents supports the hypothesis of continental drift.

The hypothesis that continents have slowly moved to their current locations is called ___

Plates move apart at ___ boundaries

The alignment of iron minerals in rocks when they are formed reflects the fact that Earth's ___ has reversed itself several times in the past.

A lack of explanation for continental drift prevented many scientists from accepting that a single supercontinent called ___ once existed

The Glomar Challenger provided support for the theory of plate tectonics by providing ___

Plates slide past one another at ___

The boundary between two plates moving together is called a ___

Seafloor spreading occurs because ___

While studying the ocean floor, scientists found ___ bands of magnetism

Continental drift states that continents have moved ___ to their current location

Wegener believed that the continents originally broke apart about ___ years ago

A fossil plant that helps support the theory of continental drift is ___

Matching ___ on different continents are evidence for continental drift

Bands of rock on the seafloor showing alternating magnetic orientation indicate Earth's magnetic field has ___

A ___ is a sensitive device used to detect magnetic fields on the seafloor

___ currents inside Earth might drive plate motion

Scientists believe that differences in ___ cause hot, plasticlike rock in the astenosphere to rise toward Earth's surface

In order to complete a convection current, the rising material must eventually ___ Earth

The Great Rift Valley in Africa is a ___

The Andes mountain range of South America was formed at a ___

Active volcanoes are most likely to form at ___

___ are formed when two continental plates collide

The ___ is (are) an example of a transform boundary

A ___ forms where two oceanic plates collide

The seafloor spreading theory was proposed by ___

As Earth's plates collide, ___ form at the plate boundaries

The cycle of heating, rising, cooling, and sinking is called a ___

Ocean floor rocks are ___ continental rocks