Q. Consider the following differences between the Oceanic Crust and Continental Crust:
  1. The Continental crust is thicker in comparison to the Oceanic Crust
  2. The Continental crust has more of quartz , while the Oceanic Crust has more of Feldspar
  3. The Continental Crust is otherwise called SIMA, while the Oceanic Crust is otherwise called SIAL
  4. The rocks that make the continental crust are little denser than those making Oceanic crust.
How many of the above statements is / are correct?

Answer: Only 1
Notes: Among the statements about the differences between the Oceanic Crust and Continental Crust, the correct statements are:
  1. The Continental crust is thicker in comparison to the Oceanic Crust: True. Generally, the continental crust is thicker than the oceanic crust. The average thickness of the continental crust is around 35-40 kilometers, whereas the oceanic crust is usually around 5-10 kilometers thick.
  2. The Continental crust has more quartz, while the Oceanic Crust has more feldspar: False. Both the continental crust and the oceanic crust contain different types of minerals, including quartz and feldspar, but the relative proportions may vary. It is not accurate to claim that one crust has more quartz and the other has more feldspar.
  3. The Continental Crust is otherwise called SIMA, while the Oceanic Crust is otherwise called SIAL: False. The terms SIMA and SIAL are outdated and not commonly used today. Previously, SIMA (Silica and Magnesium) was used to refer to the oceanic crust, while SIAL (Silica and Aluminum) was used for the continental crust. However, these terms are no longer widely recognized or used in modern geology.
  4. The rocks that make the continental crust are little denser than those making the Oceanic crust: False. The rocks that make up the continental crust are generally less dense than those forming the oceanic crust. The continental crust is composed of various types of rocks, including granite, which has a lower density compared to the basaltic rocks that form the oceanic crust.
Therefore, the correct statement is only the first one: "The Continental crust is thicker in comparison to the Oceanic Crust."

This question is part of UPSC Daily 20 MCQ Series Course on GKToday Android app.