Experiment demonstrating magnetic field changes as evidence for seafloor spreading.

Problem Analysis:

The task asks us to determine what evidence supports seafloor spreading. The question is presented in a table format with two columns: "Evidence" and "Explanation." We need to match the given pieces of evidence with their corresponding explanations.

#### Key Concepts:
1. Seafloor Spreading: This is a process where tectonic plates move apart from each other at mid-ocean ridges, allowing magma to rise and cool, forming new oceanic crust.
2. Mid-Ocean Ridges: These are underwater mountain ranges where new oceanic crust is formed due to seafloor spreading.
3. Magnetic Reversals: Earth's magnetic field periodically reverses its polarity (north and south poles switch places). These reversals are recorded in the rocks as they cool and solidify, providing a timeline for the formation of oceanic crust.
4. Symmetry of Rocks: Rocks on either side of a mid-ocean ridge should show similar patterns if they were once connected and have moved apart over time.

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Given Information:

The table provides the following pieces of evidence and explanations:

#### Evidence:
1. Rocks on either side of a mid-ocean ridge are symmetrical.
2. New rock forms at mid-ocean ridges.
3. Magnetic reversals are recorded in rocks.

#### Explanation:
A. New rock forms at mid-ocean ridges.
B. Rocks on either side of a mid-ocean ridge are symmetrical.
C. Magnetic reversals are recorded in rocks.

We need to match each piece of evidence with its correct explanation.

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Solution:

Let’s analyze each piece of evidence and match it with the appropriate explanation:

1. Evidence: Rocks on either side of a mid-ocean ridge are symmetrical.
- Explanation: This symmetry suggests that the rocks on either side of the mid-ocean ridge were once part of the same continuous crust but have moved apart over time due to seafloor spreading. This is a direct consequence of the process.
- Match: B. Rocks on either side of a mid-ocean ridge are symmetrical.

2. Evidence: New rock forms at mid-ocean ridges.
- Explanation: At mid-ocean ridges, magma rises from the mantle and cools to form new oceanic crust. This is a fundamental aspect of seafloor spreading.
- Match: A. New rock forms at mid-ocean ridges.

3. Evidence: Magnetic reversals are recorded in rocks.
- Explanation: As new oceanic crust forms at mid-ocean ridges, it records Earth's magnetic field at the time of its formation. Over millions of years, these magnetic reversals create a striped pattern on either side of the ridge, which can be used to date the age of the crust and support the theory of seafloor spreading.
- Match: C. Magnetic reversals are recorded in rocks.

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Final Answer:

\[
\boxed{
\begin{array}{|c|c|}
\hline
\textbf{Evidence} & \textbf{Explanation} \\
\hline
\text{Rocks on either side of a mid-ocean ridge are symmetrical.} & \text{B. Rocks on either side of a mid-ocean ridge are symmetrical.} \\
\hline
\text{New rock forms at mid-ocean ridges.} & \text{A. New rock forms at mid-ocean ridges.} \\
\hline
\text{Magnetic reversals are recorded in rocks.} & \text{C. Magnetic reversals are recorded in rocks.} \\
\hline
\end{array}
}
\]

This matching demonstrates how each piece of evidence directly supports the concept of seafloor spreading.