GEO GIRL Courses

Earth’s Age - How We Know Earth is 4.55 Billion Years Old

Learn how relative and radiometric dating, radioactive decay, and rocks establish Earth’s age at 4.55 billion years.

• YouTube
• 26 minutes
• Self-Paced
• Free Video

Paterae- Io’s Most Common Volcanic Feature- Surprisingly Different Than Earth Volcanism - GEO GIRL

Explore Io’s common paterae—lava lakes unlike Earth’s—through their distribution, heat flow, composition, morphology, formation, and unresolved volcanic behavior.

• YouTube
• 23 minutes
• Self-Paced
• Free Video

Io's Lava Composition and Potential for a Magma Ocean - GEO GIRL

Examines how Io’s lava composition, viscosity, and silica content reveal hypotheses about its mantle and possible magma ocean.

• YouTube
• 21 minutes
• Self-Paced
• Free Video

Marine Life in Triassic and Jurassic - Why Life Recovered Slowly After Permian Extinction

Explains why marine life recovered slowly after the Permian extinction and how Triassic–Jurassic reefs, predators, and vertebrates emerged.

• YouTube
• 21 minutes
• Self-Paced
• Free Video

How to Identify Igneous Rocks in Thin Section and Hand Sample - GEO GIRL

Practice identifying igneous rocks and their minerals from hand samples and thin sections, using visual clues to distinguish similar rock types.

• YouTube
• 31 minutes
• Self-Paced
• Free Video

Geology of the Carboniferous and Permian - 360-252 Million Years Ago

Explore how continental collisions formed Pangea, built mountain ranges, and transformed Late Paleozoic climate and sea levels.

• YouTube
• 21 minutes
• Self-Paced
• Free Video

Europa's Core, Mantle, and Water Shell - What We Know and How We Know It

Explains how gravity, magnetic-field, and geological evidence reveal Europa’s layered interior and support a salty liquid ocean beneath its icy shell.

• YouTube
• 21 minutes
• Self-Paced
• Free Video

Life in the Cambrian and Ordovician - GEO GIRL

Explore Cambrian and Ordovician life, from reef builders and predators to first vertebrates, evolutionary experimentation, biodiversity, and mass extinction.

• YouTube
• 27 minutes
• Self-Paced
• Free Video

Anaerobe to Aerobe - How Oxygen Changed Life on Earth Forever

Trace how oxygen transformed early Earth's metabolisms, triggered the Great Oxidation Event and extinctions, and enabled complex eukaryotic life.

• YouTube
• 25 minutes
• Self-Paced
• Free Video

Cambrian Explosion - More Like Precambrian Explosion and Cambrian Skeletonization

Examines why the Cambrian “explosion” was more likely a pre-Cambrian radiation followed by increased skeletonization, and how oxygen and extinction shaped animal diversification.

• YouTube
• 29 minutes
• Self-Paced
• Free Video

Neogene Life and Human Evolution from Early Apes to Australopithecus to Homo

Explore how Neogene climate change shaped the evolution of apes, larger brains, stone tools, Neanderthals, and Homo sapiens.

• YouTube
• 23 minutes
• Self-Paced
• Free Video

When Life Moved to Land and the Disastrous Consequences

How life conquered land—and how expanding terrestrial life helped trigger Earth’s first two mass extinctions.

• YouTube
• 24 minutes
• Self-Paced
• Free Video

Metamorphism of Pure vs Impure Carbonates - Marbles vs Calc-Silicates

Explains how pure and impure carbonate rocks transform into marbles and calc-silicates through mineral changes controlled by pressure, temperature, and CO₂.

• YouTube
• 22 minutes
• Self-Paced
• Free Video

Metamorphism of Basalt and Gabbro - Metabasite Mineral Assemblages

Trace how basalt and gabbro transform across metamorphic facies through pressure–temperature changes in mineral assemblages and rock textures.

• YouTube
• 32 minutes
• Self-Paced
• Free Video

Early Cenozoic Life - Megalodon Roamed, Mammals Go Back to Sea, Huge Birds Hunt Horses

A tour of Paleogene life, from walking whales and megalodon to grasslands, diversified mammals, and giant predatory birds.

• YouTube
• 21 minutes
• Self-Paced
• Free Video