THE SHIMMERING CAVERNS · ROCKLING
Sedimentary Rocks
Crystal Waterfall
Learn with Rockling, then use your clues in the adventure. Pause whenever you need time to read or think.
Speech bubbles tell the story. Music and sound effects are optional; use the player’s volume control.
Your Crystal Waterfall adventure
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Rockling — Sedimentary Rocks Crystal Waterfall
Rockling here! You found my favorite listening spot: Crystal Waterfall.
From this railing, I watch grains settle in quiet pools.
The Grumblies scrambled our process markers. Could you help?
We'll follow the grains carefully. Here's what I know.
Sediment includes loose pieces of rock and mineral.
Some pieces are gravel. Others are sand or tiny mud particles.
Weathering breaks rock down at or near Earth's surface.
Water, temperature changes, and other processes can weather rock.
Erosion moves weathered material from one place to another.
Water, wind, ice, and gravity can move sediment.
Our waterfall story gives us a place to imagine moving grains.
When transported sediment settles, that's deposition.
Moving water may drop grains as it slows.
New sediment can collect above older sediment.
Loose layers aren't automatically solid rock. More changes are needed.
As layers are buried, weight presses sediment together.
We call that compaction. Spaces between grains can shrink.
Dissolved minerals can crystallize in spaces between the grains.
They bind grains together. That's cementation.
This is natural mineral cement, not glue from a bottle.
Sand-sized grains can become sandstone through compaction and cementation.
Very fine muddy sediment can become shale.
Its tiny particles can be difficult to see individually.
But not every sedimentary rock begins as broken rock grains.
Some limestone forms from accumulated shells and skeletal material.
Other sedimentary rocks form when dissolved minerals come out of water.
Hmm... nature has more than one way to build rock.
Help me label this clue: grains stop moving and settle.
Is that erosion or deposition? Think about what changed.
Deposition! Erosion carries material; deposition leaves it in a place.
Good observation. Now those process markers won't trick us.
Does this process need the grains to melt?
No. Compaction and cementation join sediment without melting it.
Weathering breaks down. Erosion moves. Deposition settles.
Compaction presses grains. Cementation binds them.
Sedimentary rocks can also form from shells or dissolved minerals.
We're back beside the waterfall, with the processes in order.
Bring those clues into the adventure. I'll be beside you.
Ready when you are. Careful thinking makes a good explorer.
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