The weight of a subducting plate helps to pull the lithosphere into a subduction zone in a process called ridge push. ______________________________

Seafloor spreading occurs because ____.

The boundary between two plates moving together is called a ____.

Wegener believed that the continents were assembled as part of a supercontinent about ____ years ago.

The driving forces of tectonic plates are related to convection currents in Earth’s ____.

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

Scientists believe that differences in ____ cause hot, plasticlike rock in the asthenosphere to rise toward Earth's surface.

Active volcanoes are most likely to form at ____.

Plates of the lithosphere float on the ____.

A vast, underwater mountain chain is called a(n) _________.

Features found at divergent plate boundaries include ____.

Matching ____ on different continents are evidence for continental drift.

The youngest rocks on the ocean floor are located ____.

The ____ is (are) an example of a transform boundary.

The crust and upper mantle make up Earth's ____.

What new technology was used to map the seafloor beginning in the 1940s and 1950s?

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