Why does sandstone have layers?
Show answer & explanation
Answer: Sediment deposited at intervals
Seasonal color changes — Wrong. Layers aren't from seasonal color changes—they're separate deposits of sediment laid down at different times with varying conditions (flood, drought, etc.).
Plants create dark bands — Wrong. While organic material can darken layers, the layering (stratification) itself is from sediment deposited in distinct episodes over time.
Sediment deposited at intervals ✓ — Correct! Sandstone layers (strata) form as sediment is deposited over time—each layer represents a deposition event (flood, storm, etc.). Conditions vary: different sediment size, mineral content, or organic matter create visible boundaries. Over millions of years and compression, these become distinct rock layers preserving Earth's history!
More Earth Science questions
- Why can a river turn orange downstream even if the strongest acidic water enters from one tiny spring along the bank?
- Why might two Arctic streams look similarly rusty but need different chemical diagnoses?
- Why can thawing permafrost make a stream more acidic instead of simply adding cold meltwater?
- In folded Appalachians, why can one rock layer become a ridge while its neighbor becomes a valley?
- Why do some fresh earthquake fault scarps become rounded faster than others?
- Why can a long active fault affect more river basins than a short one?