superposition helps us to determine that the lava flow is than the underlying surface.
What does superposition tell us about lava flow and the underlying surface?
Answer: The principle of superposition is a fundamental concept in geology. It states that in any sequence of undisturbed sedimentary rocks or lava flows, the oldest layers are at the bottom, and the youngest layers are at the top.
When it comes to lava flows, if a lava flow is observed on top of a surface, this means:
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Relative Age: The lava flow is younger than the surface it covers. This is because it had to flow over the already existing surface, making the surface older than the lava flow.
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Layering: Like sedimentary layers, sequential lava flows stack over time. Older flows will be beneath newer ones.
Example: Imagine pouring syrup onto a pancake. The pancake (representing the underlying surface) existed before the syrup. Therefore, the syrup is younger than the pancake.
Summary: The principle of superposition helps us understand that a lava flow is younger than the surface it covers, as it must come afterward.