Zircon and apatite U-Pb age constraints from the Bundelkhand craton and Proterozoic strata of central India: Insights into craton stabilization and subsequent basin evolution

The geologic processes involved in attaining strengthened cratonic lithosphere remain debated despite their importance for stabilization and long-term preservation. In central India, stabilization of the Bundelkhand craton has conventionally been attributed to the youngest magmatic event impacting the craton at similar to 2.5 Ga, though the post-amalgamation evolution of the craton prior to Proterozoic basin development is poorly understood. This study presents new basement zircon and apatite U-Pb age data along with new detrital zircon U-Pb age data from Proterozoic marginal sedimentary basin deposits to explore the post-magmatic and burial evolution of the Bundelkhand craton. Apatite from similar to 3.4-2.5 Ga granitoids and gneisses collected across the similar to 250 km wide craton yielded near uniform U-Pb ages between similar to 2.4-2.3 Ga, indicating broad-scale exhumation of the Bundelkhand craton through mid-crustal depths following amalgamation and felsic magmatism. Unroofing of the Bundelkhand craton at this time is corroborated by similar to 2.7-2.5 Ga detrital zircon U-Pb age peaks from basal sandstones of the Bijawar and Gwalior groups, which lie in direct nonconformable contact with the craton along both its southeastern and northwestern margins, respectively. These age populations reveal an abundance of zircon sourced directly from the Bundelkhand craton, and a sub-population of similar to 2.2-2.3 Ga grains provide a maximum depositional age for the oldest strata deposited on the craton. We speculate that the redistribution of heat producing elements associated with shallow emplacement of Bundelkhand granitoids and subsequent erosion may have enhanced lithospheric strengthening and facilitated a long-term thermal regime that promoted craton stability by similar to 2.2 Ga. Following stabilization, far-field marginal tectonism likely influenced the vertical motions within the Bundelkhand craton, inducing stages of broad subsidence and erosion recorded within the strata of the Lower and Upper Vindhyan successions.

Automated summary

This study investigates the post-magmatic and burial evolution of the Bundelkhand craton by analyzing new U-Pb age data from basement zircon and apatite, as well as detrital zircon from Proterozoic marginal sedimentary basin deposits. The results suggest broad-scale exhumation of the Bundelkhand craton around 2.4-2.3 billion years ago, with potential lithospheric strengthening due to heat producing elements redistribution. Far-field marginal tectonism following stabilization may have influenced vertical motions within the craton, leading to stages of subsidence and erosion.