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49 free Geology trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Geology is the story of a 4.54-billion-year-old planet told by its rocks, and these 46 geology trivia questions and answers cover the whole plot. You will meet the people who worked it out, from Nicolas Steno's shark teeth and James Hutton's Siccar Point to Alfred Wegener's drifting continents, Marie Tharp's map of the seafloor and Inge Lehmann's inner core. You will cover the machinery too: the seven or eight major plates, the three kinds of boundary, hotspots under Hawaii and Yellowstone, subduction at the Mariana Trench and the collision still lifting the Himalayas. The quiz also takes in the geologic time scale, the Great Oxidation Event, the Chicxulub impact, the Mohs scale, why pumice floats and marble shines, and the landmarks that make geology visible: the Grand Canyon, the Giant's Causeway, Uluru, Devils Tower and Mount St. Helens. It suits earth-science students, pub-quiz teams and anyone who picks up interesting rocks on walks. Easy questions ask which river carved the Grand Canyon; hard ones ask how old the Acasta Gneiss is. Every answer is checked against Wikipedia and geological survey sources, and each question shows its source once you answer.
30 of 49 questions with answers and explanations. Play the quiz
Q 01Which Scottish scientist, author of the 1788 Theory of the Earth, is called the father of modern geology?
James Hutton
His angular unconformity at Siccar Point convinced visitors the Earth showed 'no vestige of a beginning, no prospect of an end'.
Q 02What did Alfred Wegener name the single ancient landmass in his 1912 continental drift theory?
Pangaea
He first called it the 'Urkontinent'; the Greek name means 'all land'. He died on a Greenland expedition in 1930, decades before his idea was accepted.
Q 03What was Alfred Wegener's field, which made geologists slow to accept continental drift?
Meteorology
He was a climatologist and meteorologist who made four Greenland expeditions; acceptance came only after seafloor spreading was confirmed in the 1960s.
Q 04What is the accepted age of the Earth, in billions of years?
4.54
Clair Patterson fixed it in 1956 by uranium-lead dating the Canyon Diablo meteorite, since Earth's own oldest rocks have been recycled.
Q 05Earth's oldest known minerals, 4.4-billion-year-old zircons, come from the Jack Hills of which country?
Australia
They are older than any surviving rock; the oldest intact rocks, the Acasta Gneiss of Canada, are about 4.03 billion years old.
Q 06The Acasta Gneiss, the oldest known intact crustal rock, lies in which Canadian territory?
Northwest Territories
It sits about 300 km north of Yellowknife on the edge of the Slave Craton, mostly hidden under glacial deposits.
Q 07How many major tectonic plates is Earth's lithosphere usually said to be divided into?
Seven or eight
Plus dozens of minor 'platelets'; the Nazca plate moves about 160 mm a year, roughly the speed hair grows.
Q 08What is the strongest driver of plate motion, according to modern geologists?
Slab pull from subducting crust
Cold, dense oceanic crust sinking into the mantle drags the rest of the plate along behind it.
Q 09Which Danish seismologist discovered Earth's solid inner core in 1936?
Inge Lehmann
The inner core is a mostly iron-nickel ball about 1,220 km in radius, hotter than the Sun's surface but solid under pressure.
Q 10The Mohorovičić discontinuity, or 'Moho', marks the boundary between which two layers of the Earth?
Crust and mantle
It shows up as a jump in seismic wave speed; the crust above it is only 5 to 70 km thick.
Q 11Which layer of the Earth is liquid and generates the planet's magnetic field?
The outer core
Convection in the molten iron-nickel outer core acts as a dynamo; the inner core beneath it is solid.
Q 12In which epoch of the geologic time scale are we living, which began about 11,700 years ago?
Holocene
It sits inside the Quaternary period, the Cenozoic era and the Phanerozoic eon.
Q 13Roughly what share of Earth's history is covered by the Precambrian, the time before complex life?
About 88%
The Phanerozoic, with all its trilobites, dinosaurs and people, is only the last 12 percent.
Q 21The most powerful earthquake ever recorded, magnitude 9.5 in 1960, struck which country?
Chile
The Great Chilean earthquake of 22 May 1960 sent tsunamis as far as Hawaii and Japan.
Q 22On the Mohs hardness scale devised in 1812, which mineral sits at 1, the softest?
Talc
Diamond is 10, but the scale is ordinal: diamond is actually about four times harder than corundum at 9.
Q 23Which mineral group makes up about 60 percent of the Earth's crust?
Feldspar
The name comes from the German for 'field flake'; Apollo moon rocks and Curiosity's Martian samples are rich in it too.
Q 14Which of these is one of the four formally defined eons of Earth's history?
Hadean
The four are Hadean, Archean, Proterozoic and Phanerozoic; the others listed are periods.
Q 15Nicolas Steno, who set out the law of superposition in 1669, realised "tongue stones" were actually what?
Fossil shark teeth
He dissected a shark's head in 1666; he later became a Catholic bishop and was beatified in 1988.
Q 16Which principle popularised by Charles Lyell holds that 'the present is the key to the past'?
Uniformitarianism
Darwin took volume one aboard the Beagle and later said it showed how 'incomprehensibly vast' past time had been.
Q 17The 1980 Mount St. Helens eruption began with the largest what in recorded history?
Landslide
The debris avalanche raced at up to 155 mph and the mountain lost about 1,300 feet of height; 57 people died.
Q 18The Chicxulub crater lies buried beneath which peninsula?
Yucatán
Pemex geophysicists found it in 1978; the worldwide iridium spike in boundary clay pointed to an impact.
Q 19Which asteroid-rich element was found concentrated in the clay layer marking the end of the Cretaceous?
Iridium
The Alvarez team's discovery in 1980 preceded the identification of the crater itself.
Q 20On the Richter scale, each whole-number step multiplies the measured amplitude by what factor?
Ten
Energy rises about 31.6-fold per step; seismologists now mostly use the moment magnitude scale instead.
Q 24The Giant's Causeway's roughly 40,000 interlocking columns are made of which volcanic rock?
Basalt
Cooling lava contracted into mostly hexagonal columns 50 to 60 million years ago; UNESCO listed it in 1986.
Q 25Roughly how old, in billions of years, is the Vishnu Schist at the very bottom of the Grand Canyon?
2
The Vishnu Schist in the Inner Gorge sits below the 'Great Unconformity', a half-billion-year gap in the record.
Q 26The Mid-Atlantic Ridge is which type of plate boundary?
Divergent
New crust forms as the plates spread about 2.5 cm a year; Iceland is one of the few places the ridge rises above the sea.
Q 27Which cartographer's 1950s map revealed the Atlantic's rift valley, a find her partner first dismissed as 'girl talk'?
Marie Tharp
Working with Bruce Heezen, Tharp was barred from research ships; the Library of Congress later named her one of the century's four greatest cartographers.
Q 28The San Andreas Fault marks the boundary between the North American Plate and which other?
Pacific
It is a right-lateral strike-slip fault about 1,200 km long, named by Andrew Lawson in 1895; the 1906 quake ruptured 430 km of it.
Q 29Roughly how long ago was Yellowstone's last giant eruption, the Lava Creek event?
640,000 years
It threw out about 1,000 cubic kilometres of ash; the hotspot has left a trail of older calderas along the Snake River Plain.
Q 30Which Canadian geophysicist proposed in 1963 that Hawaii formed as the seafloor moved over a hotspot?
J. Tuzo Wilson
The Hawaiian-Emperor chain runs 6,200 km with a mysterious 60-degree bend; the newest volcano, Kamaʻehuakanaloa, is still underwater.