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
- In folded Appalachians, why can one rock layer become a ridge while its neighbor becomes a valley?
- Loose material moves downhill from a fresh fault scarp, rounding it. What sets the smoothing speed?
- Why can a long active fault affect more river basins than a short one?
- Why does erosion happen faster near active faults than in areas with heavy rain?
- Why can quartz sand with beryllium-10 reveal how fast a whole river basin erodes?
- Earthquake shaking lasts seconds. How can it leave rock easier for later rivers to erode?