At this point in the story
Cenozoic Era
the current era; includes the formation of the Himalayas, Alps, Rocky Mountains, and Andes, essentially all of the major mountain ranges detailed on the Mountain Ranges page.
A sense of scale
Almost all of time
came before us.
The Precambrian occupies about 88% of this scale. That imbalance is the story.
66 million years ago – present
Present-day photograph · Himalayas · not an ancient-Earth reconstructionA planet still changing.
Cenozoic Era
Choose your moment
Approximate boundaries follow the supplied content. “Precambrian” groups multiple eons; Paleozoic, Mesozoic, and Cenozoic are eras. The detail view uses a separately labelled scale.
Landmarks in deep time.
Select a marker to place it on the scale, or follow its story.
Ancient continental crust
Some of Earth's oldest exposed rocks are gneiss.
Meet gneiss ↗Himalayas
Began forming approximately 50 million years ago; still actively rising today.
Read the range’s story ↗Andes
Formation began roughly 200 million years ago, with the modern range's major uplift occurring within the last 25 million years.
Read the range’s story ↗Rocky Mountains
Primary formation (the Laramide orogeny) occurred roughly 80–55 million years ago.
Read the range’s story ↗Appalachian Mountains
Began forming approximately 480 million years ago.
Read the range’s story ↗Alps
Began forming approximately 65 million years ago; still tectonically active.
Read the range’s story ↗Sierra Nevada
Uplift primarily over the last 5–10 million years (though the underlying rock, largely granite, is much older).
Read the range’s story ↗Cascades
The current volcanic arc has been active for roughly the last 5–7 million years, though volcanism in the region extends further back.
Read the range’s story ↗Black Hills
Uplift occurred roughly 65–70 million years ago.
Read the range’s story ↗Ural Mountains
Began forming approximately 300–250 million years ago.
Read the range’s story ↗Karakoram
Began forming alongside the Himalayas, roughly 50 million years ago.
Read the range’s story ↗Caucasus Mountains
Began forming roughly 28–23 million years ago.
Read the range’s story ↗Zagros Mountains
Began forming roughly 25–20 million years ago, with major uplift continuing into the last 5 million years.
Read the range’s story ↗Scandinavian Mountains
Began forming roughly 500–400 million years ago.
Read the range’s story ↗Southern Alps
Uplift primarily within the last 5–10 million years, and ongoing.
Read the range’s story ↗