The arc sequence in the lower Shyok area comprises volcanics (Shyok Volcanics) and intra-arc basin sediments (Hundiri, Saltoro Flysch and Saltoro Molasse formations). Biostratigraphic investigations on the Hundiri Formation indicate that this lithounit contains several Aptian-early Albian orbitolinids comprising Mesorbitolina, Orbitolina, Praeorbitolina, Palorbitolinoides, Palorbitolina, ?Neorbitolinopsis and Paracoskinolina. The orbitolinid taxa from the Shyok tectonic belt are comparable with those known to occur in Ladakh, Chitral, Burzil Pass (Indo-Pak region), Afghanistan, South Tibet and Myanmar. Fossil data suggest the existence of transgressive Neo-Tethys sea during Early Cretaceous, north of the Indian Plate. [ABSTRACT FROM AUTHOR]