2017/06/29 by Stephen Sheppard, S. Sheppard, B. Rasmussen +12
Computer Science · Earth and Planetary Sciences · #Geochemistry and Geologic Mapping #Geological and Geochemical Analysis #earthquake and tectonic studies
paper · doi:10.1144/jgs2017-051
openalex publication_date 2017/06/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Nallamalai Fold Belt comprises late Palaeoproterozoic to Mesoproterozoic sedimentary rocks deformed into a fold-and-thrust belt along the eastern side of Peninsular India. The age of thin-skinned thrusting, folding and low- to medium-grade metamorphism in the belt is unclear, with estimates ranging from Palaeoproterozoic to early Palaeozoic. A possible Pan-African age for thrusting has previously been inferred from Rb–Sr dating of muscovite in shear zones from the adjacent Krishna Province (501 – 474 Ma) but these structures are separated from the Nallamalai Fold Belt by a major thrust. Here, we present in situ U–Pb dating of metamorphic monazite within a low-grade metasedimentary rock in the Nallamalai Fold Belt at the Mangampeta barite mine. Our date of 531 ± 7 Ma for the monazite is the first direct evidence that west- to NW-directed nappe stacking, folding and low-grade metamorphism in the fold belt are related to Pan-African incorporation of India into the Gondwana supercontinent.