Not Just Rocks: The Geology Quiz

The mantle "flows" over an extremely long time, but it primarily consists of solid rock.

Limestone is highly soluble in water compared to other forms of rock. Water erodes passages through limestone and creates the caves and other features common to karst topography.

Earth formed approximately 4.54 billion years ago when a disk of debris gathered into a rocky sphere, a process known as accretion.

Glaciers scoop rocky debris from the ground and slowly carry it forward, eventually depositing the debris when the glacial ice melts.

The magma was cooled by ocean water, forming the Hawaiian islands.

Coal has been used as a fuel for thousands of years.

The series of active tectonic plate boundaries surrounding the Pacific Ocean accounts for the majority of the world's earthquakes and volcanoes.

While it's not the only theory, geologists think a planet the size of Mars may have impacted Earth and created the moon not long after Earth formed.

Niagara Falls has "moved" several kilometers over thousands of years.

Over millions of years, ocean waves grind rocks down to grains of sand. The color of a beach depends on the mineral composition of the nearby rocks that formed it.

Geysers require specific "plumbing" (usually a lower chamber with a constrained opening at the surface) for the water to become superheated.

Russia's Kola Superdeep Borehole reached a depth of 12,262 meters in 1989 and has never been surpassed.

The Greek name Pangaea can be roughly translated to English as "whole Earth."

Earth gets hotter the deeper you go. The temperature of the mantle ranges from 1832 F (1000 C) to 6692 F (3700 C).

The deepest part of the Mariana Trench is nearly seven miles below the surface of the ocean.

Earthquakes waves move differently through different materials, which is how seismologists know the outer core is liquid and the mantle slowly shifts via convection.

Examples of metamorphic rock include gneiss and marble.

Impactites are considered metamorphic even though they don't form over the millions of years required for most metamorphic rocks.

Asbestos and lead are both naturally occurring minerals. Pyrex is a brand name for heat-resistant glass.

Pahoehoe is pronounced "pah-hoey-hoey" and is a term of Hawaiian origin.

Barrier islands are often made of sand dunes and other loose material, and they can shift, change or disappear during storms. They help protect shorelines from erosion and storm surges.

Transported soil is moved by erosion and gravity. Its origin can often be found uphill, but wind can carry transported soil hundreds or thousands of miles, even across oceans.

Halite forms when salty bodies of water dry up, leaving salt deposits that can be hundreds of meters thick.

An oblate spheroid is a squashed sphere — Earth is slightly flatter at the poles and bulges at the Equator.

During the last glacial period, glacial ice in Europe and North America was up to 3 kilometers (1.9 miles) thick. The incredible weight pushed down on the crust, and in some areas the crust is still springing back into shape.

The process that creates the magnetic field is complex, but it is caused by molten iron in the outer core moving due to heat convection from the hotter, solid inner core.

The remnants of enormous impact craters, some of them 100 miles (161 kilometers) or more in diameter, can be found worldwide, with some of the largest in South Africa, Canada and Mexico.

Cinnabar is mercury sulfide, an incredibly toxic chemical. You should never handle cinnabar, much less taste it.

The crust is spreading out at the Mid-Atlantic Ridge because it's a divergent boundary between the North American and Eurasian tectonic plates as well as the South American and African plates.

It's believed that ice dam formation and collapse caused several massive floods during the last ice age, unleashing incredible energy and reshaping the surrounding area.