## 7 Discussion
### Detrial Zircon Provenance of Chitaravatta Formation  
The composite PDP of the U-Pb ages of the Chitarwatta Formation shows that the major age clusters are around \(\sim\)390-1150 Ma, \(\sim\)1200-1800 Ma, and \(\sim\)2237-2535 Ma (Figure 6). The age cluster \(\sim\)390-1100 Ma matches well with the TH age pattern, whereas the \(\sim\)1200-1800 Ma and \(\sim\)2237-2535 Ma match with the LH and HH age patterns, respectively. Furthermore, the younger age cluster (\(\sim\)40-170 Ma) is representative of Eurasian sources (Figure 6). However, the few younger ages, between \(\sim\)120-170 Ma, match with the TH volcanic rocks and the ophiolitic sources [51].  
The younger age pattern, with detrital ages between \(\sim\)60 Ma and \(\sim\)90 Ma, are representative of the Kohistan-Ladakh arc. This younger pattern suggests an increased input  
Figure 6: Comparison of the composite PDPs of the studied detrital zircon samples with the adjacent source regions [3,47,52,53], and coeval sedimentary units exposed along the strike [8,54,55]. Where TH—Tethyan Himalaya, HH—Higher Himalaya, LH—Lesser Himalaya, KB—Karakoram block, LB—Lhasa block, and KLA—Kohistan–Ladakh arc.  
from Eurasian sources. However, the major population yielded Proterozoic to Cambrian ages, which is \(\sim\)70% of the total ages. This suggests an increased input from the Higher Himalaya, where Proterozoic-Cambrian granites are widely exposed [3, 47]. In addition, the Sr-Nd isotopic data of the Chitarwatta Formation yielded values that resembled the Higher Himalaya [56]. In addition, metamorphic minerals were observed in the sediments of the Chitarwatta Formation, which indicates derivation from the metamorphic rocks of the Higher Himalaya [56]. The Th/U ratio and internal zoning pattern also suggested mainly derivation from igneous sources that are closed exposed in the Higher Himalaya. The detritus of the Chitarwatta Formation evidenced post-collisional (India-Asia) sources [26]. Considering this evidence and our detrital zircon U-Pb age dataset, it can be suggested that during the deposition of the Chitarwatta Formation, the Indus drainage system fed the basin in the Sulaiman fold-thrust belt (Figure 7A,B). The inputs of the Higher Himalayan source suggest the uplifting of the Higher Himalaya since the Oligocene.  
The detrital record of the Chitarwatta Formation is compared with the coeval Murree Formation (Hazara-Kashmir syntaxal region), Dagshai Formation (India), Dumre Formation (Nepal), and Barail Formation (Bengal Basin) [1, 8, 54, 11, 55]. The coeval Murree Formation and Dagshai Formation (Subathu Basin) are exposed in the western Himalaya, the Dumre Formation represents the central Himalaya, and the Barail Formation represents the eastern Himalaya. The detrital record shows strong similarity to the Murree, Dagshai and Barail formations, whereas the detrital record of the Dumre Formation shows comparatively less similarity. This suggests that the major drainage system developed towards the west and east, while the central segment of the Himalaya was uplifted and did not receive the detritus.  
Figure 7: Tectonic model showing the paleogeographic reconstruction of the Indian plate (modified after [56]. **(A)** The Indian margin received detritus from Eurasian sources and ophiolitic sources exposed in the collision zone, 50–30 Ma. **(B)** When the deposition of the Chitarwatta Formation and its coeval units (Murree, Dagshai, Dumre, and Barail Formations) occurred in the foreland basin and exhumation of the Higher Himalaya occurred, 30–20 Ma.