| 100% | STONEAGE | 8 | It started about 2 1/2 million years ago |
| 54% | ASIA | 4 | India joined it about 50 million years ago |
| 47% | ETNA | 4 | It's about 2 1/2 times as high as Vesuvius |
| 47% | PLIOCENE | 8 | Epoch from 10 to 2 million years ago |
| 44% | JURASSIC | 8 | Period that began about two hundred million years ago |
| 43% | ASTROLABE | 9 | Early navigational aid invented about 2,200 years ago |
| 43% | ICEAGE | 6 | It ended about 10,000 years ago |
| 43% | CANYON | 6 | Grand ___, natural wonder carved by the Colorado River about 5 to 6 million years ago |
| 42% | ERODED | 6 | What the Appalachian Mountains have done since about 480 million years ago |
| 41% | DEEPSPACE | 9 | Some say it starts 2 million km from Earth |
| 41% | EOCENE | 6 | Geological epoch that terminated in the "Grande Coupure" about 33.9 million years ago |
| 40% | GONDWANA | 8 | Supercontinent that covered about one fifth of the Earth about three hundred million years ago |
| 38% | HECTARE | 7 | About 2 1/2 acres |
| 36% | PACE | 4 | About 2 1/2 feet for humans, I suppose |
| 36% | EOCENE | 6 | Epoch 50 million years ago |
| 35% | PLUTO | 5 | It's about 2,100 miles in diameter |
| 35% | PANGAEA | 7 | Supercontinent of 200+ million years ago |
| 35% | EOCENE | 6 | Epoch of 50 million years ago |
| 35% | PANGAEA | 7 | Supercontinent of 200 million years ago |
| 35% | MII | 3 | 1,017 years ago |
| 35% | OED | 3 | Ref. with more than 2 1/2 million quotations |
| 34% | GONNAMAKE | 9 | "___ It Through This Year," a song about New Year's by the Great Lake Swimmers: 2 wds. |
| 34% | EOCENE | 6 | Occurring 40 to 55 million years ago |
| 34% | ERA | 3 | Mesozoic ___ (252 to 66 million years ago) |
| 34% | HAN | 3 | Chinese dynasty of 2,000 years ago |
| 34% | ILIAD | 5 | Poem written over 2,700 years ago |
| 34% | NEWYEAR | 7 | It begins on January 1: 2 wds. |
| 34% | AIR | 3 | It's about 1% argon |
| 34% | TREELINE | 8 | It's about 2,500 feet up on Mt. McKinley |
| 34% | PLIOCENE | 8 | Epoch from two to five million years ago |