Part 1: Geology

Part 1: Vocabulary


  • Gigantic rock from outer space
  • One hit Earth about 65 million years ago and may have totally changed Earth’s climate causing extinction of dinosaurs and most other animals and plants


  • Southwestern part of North Dakota that was not touched by the last glacier
  • Deep valleys, canyons, and cliffs carved by wind and water 
  • Colorful because of clinker and other types of rocks and soil layers


  • Meat-eating animal

Cenozoic Era:

  • Most recent era
  • Began about 65 million years ago
  • “Age of Mammals”
  • Divided into Tertiary and Quaternary Periods
  • Era we live in now


  • Reptile that lived in swamps and looked something like a crocodile
  • A carnivore


  • Solid fossil fuel created from land vegetation that had been squeezed by pressure for millions of years
  • Formed during Cenozoic Era


  • The four longest divisions of geologic time


  • All are gone


  • When the last member of a species dies
  • All are gone


  • Remains of a plant or animal that has been buried in the earth (in rock, soil, ice, etc.)
  • Skeleton, bone, shell, or an imprint, such as a footprint

Fossil fuels:

  • Formed from the decayed remains of prehistoric (very ancient) plants and animals
  • Petroleum, natural gas, and coal

Geologic Time:

  • Divides Earth's history into time periods
  • Indicates big changes that took place on Earth
  • Constantly being refined


  • Scientists who study the earth


  • The scientific study of the earth


  • Gigantic sheets of ice
  • Thousands of feet thick
  • Moved south over 20 times from Canada into North Dakota
  • Pushed everything in its path ahead of it like a giant bulldozer
  • Scraped off hills, ground up rocks, and carried huge amounts of earth
  • Hills were formed from great heaps of material left by melting glaciers


  • Plant-eating animal

Igneous rock:

  • Any rock formed from magma

Lake Agassiz:

  • Gigantic lake formed because glaciers in Canada blocked rivers flowing north
  • Named after Louis Agassiz, a geologist
  • 700 miles long, 200 miles wide, 300 feet deep
  • Covered eastern part of North Dakota, part of Minnesota, and parts of Canada
  • Has been gone for thousands of years
  • Red River Valley in eastern North Dakota is the floor of this prehistoric lake
  • Some of the world’s best farmland is located in this ancient lake bed


  • Very soft coal that contains a lot of moisture
  • Burns fast and does not give off as much heat as other coals
  • Surface-mined
  • Formed during Tertiary Period of Cenozoic Era


  • Molten material deep inside the earth

Mesozoic Era:

  • From about 248 million years ago to about 65 million years ago
  • Lasted about 183 million years
  • “Age of Reptiles”
  • Dinosaurs lived during this era


  • Giant lizard that lived in the ocean
  • A carnivore

Natural gas:

  • Gas fossil fuel created from tiny plants and animals that lived in oceans; squeezed by pressure and exposed to heat for millions of years
  • Formed during the Paleozoic Era


  • Scientist who study fossils


  • Study of the history and life on Earth
  • Study of fossils

Paleozoic Era:

  • From about 540 million years ago to about 248 million years ago
  • Lasted about 292 million years
  • Shallow seas came inland several times
  • Water completely covered North Dakota
  • First forests appeared
  • First four-legged animals developed

Petrified wood:

  • Stone formed from minerals filling in cells of wood as it decayed
  • Looks exactly like the plant that had been there in the first place, except it is stone
  • Petrified forest located in Badlands


  • Liquid fossil fuel created from tiny plants and animals that lived in oceans and had been squeezed by pressure for millions of years
  • Formed during the Paleozoic Era

Precambrian Era:

  • Oldest era
  • Era that lasted the longest
  • From about 4.5 billion years ago to about 540 million years ago
  • Included almost 4 billion years of Earth’s history
  • Igneous rock formed during this era
  • No animals lived during this era
  • Only microscopic plants lived during this era


  • Flying reptile
  • Had a wing-span of about 20 feet
  • A carnivore

Quaternary Period:

  • Part of the Cenozoic Era
  • Began about 1.8 million years ago
  • “Ice Age”
  • Glaciers formed and did not melt for thousands of years
  • Mastodons and woolly mammoths lived in North Dakota about 11,000 years ago
  • Period we live in now


  • Type of red rock formed from lignite coal burning underground
  • Found in the Badlands
  • Sometimes crushed and used as a road surface material instead of gravel
  • Adds color and beauty to the Badlands
  • Also called clinker


  • Small pieces of rock and dirt carried by water or wind

Sedimentary rock:

  • Rock formed by particles of sediment pressed together


  • Top layers of soil are scraped away and coal is scooped up with giant shovel-type machines
  • Lignite is mined this way

Teredo-bored petrified wood:

  • North Dakota’s state fossil
  • 60 million years old
  • Little clams called teredos drilled tiny holes into wood before it fossilized

Tertiary Period:

  • Part of the Cenozoic Era
  • Began about 65 million years ago
  • The last of the inland seas drained away
  • Rocky Mountains were formed in western United States
  • Palm trees and tropical flowers grew well in North Dakota
  • Coal formed during this period
  • Camels, tiny three-toed horses, and rhinoceros lived in North Dakota
  • About 50 million years ago North Dakota’s climate was becoming cooler and drier
  • About 30 million years ago swamps were replaced by grasslands


  • Most common dinosaur in North Dakota
  • Had a big horn above each eye and a smaller horn on its nose
  • Had a bony plate at the back of its skull that looked like a high collar
  • Could weigh as much as 10,000 pounds
  • An herbivore

Tyrannosaurus rex:

  • About 40 feet long and 20 feet tall
  • Walked on two powerful legs
  • Had arms only about three feet long
  • Had strong jaws about four feet long
  • Weighed about 12,000 pounds
  • Had 50 to 60 sharp teeth
  • A carnivore
  • Could eat up to 500 pounds of meat in one bite

Williston Basin:

  • Bowl-shaped region of sedimentary rock covering much of western North Dakota, as well as parts of South Dakota, Montana, Manitoba, and Saskatchewan
  • Contains a lot of petroleum and natural gas

Wisconsinan glacier:

  • Last glacier that moved over North Dakota
  • Entered North Dakota about 40,000 years ago
  • Stayed about 28,000 years
  • Melted away about 12,000 years ago
  • Covered almost all of North Dakota except for the southwest corner