What are the main mineral constituents of the oceanic crust?

Which one of the following rock systems in India is the main source of coal deposits?

Which one of the following processes leads to expansion of certain minerals as they take up water, causing additional stress in the rock?

Which of the following geological systems of rocks contain a rich reserve of iron ore in India?

Which of the following rocks is not likely to contain fossils?

Which of the following rocks are intrusive igneous rock formation?