Indian Stratigraphy

To determine the correct chronological sequence (from oldest to youngest) of the given Precambrian stratigraphic units, we need to understand each group's geological age and context within the Indian stratigraphy:

1. Sargur Group: This is one of the oldest geological formations in India, typically associated with the Archean eon. The Sargur Group is characterized by its high-grade metamorphic rocks and is known to be a basal complex underlying various other formations.
2. Chitradurga Group: This belongs to the Proterozoic eon and is younger than the Sargur Group. It forms part of the Dharwar Supergroup in the Karnataka region, consisting mainly of sedimentary rocks and volcanic sequences.
3. Alwar Group: Part of the Delhi Supergroup, the Alwar Group is known to be younger than both the Sargur and Chitradurga Groups. It predominantly lies within the Proterozoic eon and is known for its quartzite and slate formations.
4. Kaimur Group: This group is part of the Vindhyan Supergroup. The Kaimur Group is clearly established as being younger than the previous groups, also part of the Proterozoic eon, but it overlays the older formations in the geological time scale.

Based on this information, the correct chronological sequence from oldest to youngest is:

• Sargur Group (oldest)
• Chitradurga Group
• Alwar Group
• Kaimur Group (youngest)

Thus, the correct option is: Sargur Group, Chitradurga Group, Alwar Group, Kaimur Group.