Q 01/05

What kind of rock is coal?

A) Sedimentary

B) Volcanic

C) Igneous

D) Metamorphic

Answer · why

A) Sedimentary

Coal is a sedimentary rock because it builds up in layers from swamp plant debris that waterlogged ground kept from rotting away.

Q 02/05

What do decaying plants become first, before heat and pressure turn them into coal?

A) Tar

B) Peat

C) Shale

D) Charcoal

Answer · why

B) Peat

Peat's acidic, oxygen-poor water stops dead plants rotting, and in 1950 it had kept Tollund Man so lifelike that his finders called the police.

Q 03/05

Geologists named the Carboniferous period after the coal-rich rocks of which country?

A) Germany

B) Britain

C) United States

D) Belgium

Answer · why

B) Britain

Britain's coal-rich rocks gave the Carboniferous its name, yet that coal began as tropical swamp forest, because Europe then lay in the humid tropics.

Q 04/05

During the great coal-forming age, how did ice sheets near the South Pole help coal swamps spread?

A) Carved out lake basins

B) Dammed the rivers

C) Lowered sea levels

D) Ground rock into soil

Answer · why

C) Lowered sea levels

Lowered sea levels did it: the ice sheets locked up so much water that the seas fell, exposing broad shelves and deltas where the coal swamps took roo...

Q 05/05

Teenage chemist William Perkin stumbled on mauve dye in 1856 while trying to make which drug from coal tar?

A) Quinine

B) Morphine

C) Aspirin

D) Chloroform

Answer · why

A) Quinine

Quinine, the malaria drug, was Perkin's target; his accidental mauve launched the synthetic dye industry, and coal-tar dye firms later turned their ch...