In 1968, the drilling ship Glomar Challenger _____.

Oceanic crust is primarily _____.

The violent volcanoes of South America’s Andes Mountains are a product of _____.

The crustal assemblages that accumulate along subduction zones to form new, continental landmasses are called _____.

Lithospheric plates shear laterally past one another at _____.

How is the seafloor at a mid-ocean ridge (spreading center) different from seafloor at the edges of the ocean basin?

The Mid-Atlantic Ridge _____.

The first echo sounders were used for _____.

Bathymetry is the _____.

_____forms mainly from shells of the amoeba-like foraminifera; small, drifting molluscs called pteropods; and tiny algae known as coccolithophores.