How was the geomagnetic polarity time scale of importance in finally determing t

Question

How was the geomagnetic polarity time scale of importance in finally determing the origin of mid ocean ridges and the mechanism for “continental drift”?

What are the essential components of a soil profile (draw a sketch if you would prefer)? What would be the likely difference between a soil in the American Southwest and one in upstate New York? Why does Idaho have “famous potatoes”?

Seismic body waves travel faster in Earth’s mantle than in the crust, immediately above it. Based on what you know about Earth materials (rocks) and their building blocks (silicate minerals), why do you think that this is the case?

The elevation of the abyssal ocean floor decreases, relatively smoothly, with distance away from a mid-ocean ridge spreading center. Why is this? If the rate of spreading at a mid-ocean ridge were to increase, what might this do for the relative yet global (eustatic) level of the sea floor? How might this phenomenon be used to explain disconformites in the continental stratigraphic record?

Explanation / Answer

Polarity Reversal: At mid oceanic ridges, new crust is formed. The new crustal rocks in the form of lava have the magnetic strips and those strips orient along the dorection of earth's magnetic field. When the magnetic anomalies measured on either side of the ridge, the magnetic anomaly was symmetric, which indicates the spreading on eihter side. Broader the magnetic anomaly higher the spreading rate and tighter anomaly indicates the slow spreading rates. Continental drift is the theory explains about the movement of continents. The magnetic data showed that a continent has the magnetic field direction opposite to the present field direction. Hence, it cleared that there was movement of poles or continentd. When two continets were analyzed for magnetic data, similar direction of field was obtained in both the continents. Hence, scientists decided that the continental drift was occurred.

Seismic body waves: Seismic body waves travel faster in mantle than in crust due to the higher density in mantle. Since, velcocity is directly proportional to the density, velocity of waves more in mantle. Silicate percentage makes the material with strong bonding. Strong bonding allows the waves to travel faster.

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