Chapter 27, Problem 9RQ

To determine

The way according to which the ocean floor similar to a gigantic slow-moving tape recorder.

Answer to Problem 9RQ

The extrusion process of the basalt takes place from time to time, the direction of the magnetic field at each time recorded in rocks. Due to this behavior, it is stated that floor of the ocean behaves like a gigantic slow-moving tape recorder.

Explanation of Solution

A fine-grained and the dark-colored igneous rock, which is most commonly known as the basalt, is used to make the ocean floor. When new basalt extruded at the mid-range of the ocean, it becomes magnetized in the direction of the existing magnetic field.

The basalt's extrusion process takes place from time to time, the direction of the magnetic field at each time recorded in rocks, which can be later extracted and analyzed, thus providing a detailed magnetic history for billion years. In this way, it can be stated that the floor of the ocean behaves like a gigantic, slow-moving tape recorder.

Conclusion:

Therefore, the extrusion process of the basalt takes place time to time, the direction of magnetic field at each time recorded in rocks due to this behavior it is stated that floor of ocean behaves as a gigantic slow moving tape recorder.