Geology Expansion Pack
Dinosaur Peak
Geo facts | The Changing Earth
135 million years ago, the ground here was flat, soft, and wet. Dinosaurs left footprints that were buried and turned to stone deep underground. So why have you found them on the side of this mountain?
Bending stone
Richard points out an area on the mountain to you. Can you see where the rock layers have folded into a wavy shape? How did this happen?
Faults and folds
Faults and folds are two ways rocks deform and create mountains. A fault is a crack that happens quickly. A fold is a bend that happens slowly. They are often connected.
Shifting sedimentation
Lisa and Richard found both turtle bones and dinosaur footprints at this site. How did both marine and terrestrial fossils end up in the same place?
A shallow sea
North America looked very different in the past. During the time of the dinosaurs in the Late Cretaceous, North America was cut in half by a shallow, warm sea that ran from the Arctic Ocean to the Gulf of Mexico.
Roadside Finds
Geo facts | Past and present
Evidence of Earth’s past is embedded in its geology. Fossilized footprints, mudcracks, and sedimentary structures help us peer back in time. However, even now new events are being recorded in the Earth’s rocks.
Trace fossil formation
The journey from footprint to fossil is a long one. We’ve sped up the process to show how it happens otherwise we would never get to the end.
Which way is up?
When it comes to rocks, up isn’t always what it used to be. Over time rocks can move, deform, and even completely overturn. So how can we know which way they used to face?
Present-day deposits
Even now, geological processes are happening! This river is an example of a depositional environment in action. The flow of a river continuously carries and deposits new sediment which may become rock.
Explorer’s Valley
Geo facts | Glaciers are cool
Even though they have long since melted, we can tell that glaciers once filled this valley from the clues they left behind. What are some of the signs of past glacial activity?
Glacial till
One way you can tell that there were glaciers here is the sediment they left behind. Glacial erosion creates a distinct form of sediment called till.
Valley shapes
A valley’s shape can tell you how it was formed. This valley’s shape tells us that it was once filled with glaciers.
Sediment recycling
Where glaciers once carved out this valley, a river now continues the process. Glacial till becomes new deposits as it is carried downstream.
Forest Footprints
Geo facts | Cycling back to it
There is a cyclical nature to both rocks and life. Rocks are recycled by geological processes. Living things are recycled by biological processes. But what are some of the ways they are connected?
Soil and sediment
The forest and vegetation around this site depend on the soil to grow. Soil starts as rocks. The same ones that contain dinosaur footprints. So, what makes the soil different from rock?
Heat and pressure
The surrounding area is rich in coal. Coal is a special type of rock that formed from plants that died a long time ago. Even before the dinosaurs! How did that happen?
Footnotes on foothills
Ever wish you were taller? These foothills might be able to relate, even though they’re still considered part of the mountains.