Q 01/05

Seabed limestone now caps Mount Everest thanks to which rock-cycle process, driven by colliding continents?

A) Erosion

B) Deposition

C) Uplift

D) Subsidence

Answer · why

C) Uplift

Uplift has carried rock laid down in a shallow sea to the roof of the world: the limestone at Everest's summit still holds broken trilobites and sea l...

Q 02/05

Which fine-grained volcanic rock makes up both Earth's ocean floor and the dark 'seas' on the Moon?

A) Dacite

B) Andesite

C) Rhyolite

D) Basalt

Answer · why

D) Basalt

Basalt accounts for more than 90 percent of all volcanic rock on Earth, and the Moon's dark patches are plains of it that flooded ancient impact basin...

Q 03/05

The giant moai statues of Easter Island were mostly carved from which soft rock made of volcanic ash?

A) Chert

B) Tuff

C) Marl

D) Scoria

Answer · why

B) Tuff

Tuff, volcanic ash compressed into soft stone, was used for all but 53 of the 900-plus moai. Nearly 400 statues in various stages of completion still ...

Q 04/05

Which glassy volcanic rock, formed when lava cools too fast for crystals to grow, was chipped into razor-sharp blades?

A) Obsidian

B) Rhyolite

C) Trachyte

D) Phonolite

Answer · why

A) Obsidian

Obsidian breaks into edges so sharp that it has been tried out as surgical scalpel blades. Neolithic craftsmen traded their bladelets across southern ...

Q 05/05

Limestone that is heated and squeezed deep underground recrystallises into which rock, used to build the Taj Mahal?

A) Soapstone

B) Travertine

C) Marble

D) Alabaster

Answer · why

C) Marble

Marble lets light sink a little way into the stone before scattering back out, which gives statues carved from it a lifelike, waxy glow.