The question asks which is the oldest rock system in the Indian stratigraphic succession. Let's analyze each option to determine the correct answer.
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Dharwar Supergroup: The Dharwar Supergroup is one of the oldest geological formations in India, dating back to the Precambrian era. These rocks are primarily found in the Karnataka region and are mainly composed of schists and gneisses. They are known for their rich mineral deposits, particularly gold and iron ore. The Dharwar rocks belong to the Archean period.
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Vindhyan Supergroup: The Vindhyan Supergroup is younger than the Dharwar, dating to the Proterozoic era. It mainly consists of sedimentary rocks and is known for its deposits of limestone and sandstone. These rocks are prevalent in central India.
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Cuddapah Supergroup: The Cuddapah Supergroup is also from the Proterozoic era, mainly consisting of sedimentary rock formations, and found in the Cuddapah basin of Andhra Pradesh.
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Gondwana Supergroup: The Gondwana Supergroup is much younger, originating from the Paleozoic to Mesozoic eras. These are characterized by coal deposits and are primarily found in eastern and central India.
From the above analysis, it is clear that the Dharwar Supergroup is the oldest rock system compared to the others listed, as it dates back to the Archean period.
Therefore, the correct answer is Dharwar Supergroup.