Detrital zircon U-Pb ages and Hf isotopes of quartzites from Southern Granulite Terrane, India: Implications for the Precambrian crustal evolution and paleogeography

Tectonic evolution of Southern Granulite Terrane (SGT) of south India and its relationship with adjacent continental fragments in the context of supercontinent assembly/dispersal models has been a topic of debate. This is primarily due to the lack of robust zircon U-Pb and Hf isotopic data from different crustal blocks in SGT and its correlation with other terranes. The present study attempts to address this issue by generating new zircon U-Pb and Hf isotopic data of quartzites from a key segment in SGT and link them with similar results from adjacent continental fragments. Our new zircon U-Pb data reveal five distinct age peaks at -2500 Ma, -2000-1900 Ma, -1100-1000 Ma, -800-700 Ma and -550 Ma recorded in the samples. Hf isotopic composition of these zircons demonstrates distinct crustal growth and/or recycling episodes with juvenile magmatic addition restricted up to -1900 Ma, followed by large-scale crustal recycling episodes. The close resemblance of these detrital ages and their Hf isotopic signatures with adjacent terranes such as Madagascar, Sri Lanka, Africa, Eastern Ghats, and Antarctica point to a similar evolutionary history, suggesting a pre-Gondwanan ancestry for the assembly of these terranes.