This study reports the detrital zircon U–Pb ages of the post collisional Chitarwatta Formation, exposed along the western margin of the Indian plate at the Sulaiman fold–thrust belt (SFB), Pakistan. The Chitarwatta Formation overlies the shallow marine carbonate sequence of the Kirthar Formation and represents an Oligocene–Miocene transitional marine sequence. The sequence consists of sandstone, siltstone, and mudstone. The sandstone consists predominantly (79–82%) of quartz grains. The framework grains are sub-angular to sub-rounded and show recycled orogenic provenance. The detrital zircon U–Pb age data show the dominant population between 390 Ma and ~1100 Ma, which is ~70% of the total population. In addition to this, a significant percentage of the younger detrital ages exist between ~40 Ma and ~120 Ma. This younger age cluster indicates the northern sources, including the Kohistan–Ladakh arc (KLA) and Karakoram block (KB), whereas the provenance for the 390–1100 Ma detrital zircon is likely the Higher Himalaya (HH), with contribution from Tethyan Himalaya (TH). This post-collisional scenario suggests that the Chitarwatta Formation received detritus from the northern sources through a drainage system, named as the Indus drainage system. A comparison with the coeval units in the north (Murree Formation, Dagshai Formation, and Dumre Formation) suggests that the sediments may have been delivered through the same drainage system that shares similar detritus. Relying on the contribution of the HH detritus, we propose that the HH uplifted during the Oligocene–Miocene along the Main Central Thrust (MCT) and provided detritus to the foreland basin.

This study reports on the detrital zircon provenance of the sandstones of Early Paleocene Ranikot Formation exposed in the Fort Munro section, Sulaiman fold-thrust belt, Pakistan. This marks the Cretaceous-Tertiary boundary sequence. The detrital zircon U-Pb ages reported are mainly clustered around ~460–1100 Ma, ~1600–1900 Ma and ~2300–2600 Ma. The age cluster ~460–1100 Ma is mainly matched well with the Tethyan Himalaya. However, the age clusters ~1600–1900 Ma and ~2300–2600 Ma matched fairly with the lesser Himalayas and Higher Himalayas. In addition, the sandstone petrography suggests the craton interior provenance. The two younger Cretaceous zircon ages may be derived from the Tethyan Himalaya volcanic rocks as supported by a high (>0.3) Th/U ratio. Furthermore, the absence of the ophiolitic component ~115–178 Ma suggests that the western ophiolite may be emplaced at the same time as Ranikot Formation deposited or later. Moreover, the absence of the Eurasian (zircon with ages <100 Ma) in the Ranikot Formation excludes the possibility of the early collision along the western margin, as reported in earlier studies.