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Which of the following statements with reference to ocean crust is/are correct ?
1. The ocean crust rocks are much younger than the continental rocks.
2. The ocean crust rocks equidistant on either side of the crest of mid-oceanic ridges show similarities in terms of magnetic properties.
Select the answer using the code given below :
Explanation
Both statements are correct based on the theory of Seafloor Spreading. Statement 1 is correct because the oceanic crust is continuously being created at mid-oceanic ridges and recycled into the mantle at subduction zones. As a result, oceanic crust is rarely older than 200 million years, whereas continental rocks can be billions of years old. Statement 2 is correct because as new magma erupts at the ridge crest and cools, it solidifies and records the Earth's magnetic orientation. Because the seafloor spreads symmetrically away from the ridge, rocks located at equal distances on either side of the crest exhibit identical magnetic signatures (paleomagnetism) and ages. This symmetry provided the empirical evidence needed to support Harry Hess's hypothesis of seafloor spreading and the broader theory of Plate Tectonics.
SIMILAR QUESTIONS
Which of the following statements is/are correct? 1. The Earth’s crust is brittle in nature. 2. The mean thickness of the oceanic crust is 15 km, whereas that of the continental crust is around 30 km. Select the correct answer using the code given below.
Consider the following statements regarding the Earth's crust :
I. The continental crust is thinner under fold mountains.
II. The mean thickness of ocean crust is 30 km.
III. The Earth's crust is brittle in nature.
Which of the statements given above is/are correct?