## 2 Materials and Methods  
### Geology of the Study Area  
The Kohat Plateau within the study area (Figure 1) is characterized by a blend of lithologies owing to a broad spectrum of depositional environments from carbonate platform to marginal marine and again to carbonate platform in the Eocene. An unconformity follows in Oligocene continental settings from the Miocene onwards, as shown in Table A1 (Appendix A) and Figure S1 [38]. The region mainly contains the deformed sedimentary rocks from the Paleocene to Pliocene sequences formed due to the collision of the Eurasian and Indian plates. Tectonically, the Kohat Plateau falls in a compressional regime due to  
Figure 1: Location of the study area in the Kohat–Karak districts of the Khyber Pakhtunkhwa province of Pakistan (blue), the extent defined by corner points (1) 33 30\({}^{\prime\prime}\)9.83\({}^{\prime\prime}\) N, 70 45\({}^{\prime\prime}\)2.05\({}^{\prime\prime}\) E; (2) 33 30\({}^{\prime\prime}\)9.83\({}^{\prime\prime}\) N, 71 54\({}^{\prime\prime}\)14.87\({}^{\prime\prime}\) E; (3) 32 55\({}^{\prime}\)37.63\({}^{\prime\prime}\) N, 71 54\({}^{\prime\prime}\)14.87\({}^{\prime\prime}\) E; and (4) 32 55\({}^{\prime}\)37.63\({}^{\prime\prime}\) N, 70 45\({}^{\prime}\)2.05\({}^{\prime\prime}\) E. The extent of a published geological map of the area (Figure S1 [38]) is in black.  
a tectonic collision between the Indian and Asian plates northward of the MBT [44]. The compressional tectonics resulted in thrust sheets in the Kohat Plateau, which predominantly exposes Paleogene-recent strata [45; 46]. As a result, thrusts, broad synclines, tight anticline structures, and tight symmetrical folds striking in the east-west direction are found. The fluctuating depositional environments in the Eocene indicate the interplay of tectonics and climate, which becomes predominantly continental from the Miocene onwards in response to Himalayan orogen [47]. A detailed study of the structural geology and stratigraphy of the Kohat region is discussed by [PERSON] et al. [48]. Apart from Quaternary era surface alluvium depositions, all the tertiary era depositions are ordered from oldest to most recent: Jatta Gypsum, Mami Khel Clay [49], Kohat [50] (Eocene); Murree [51], Kamliad [52] (Miocene); Chinji [52], Nagri [52], and Dhok-Pathan (Pliocene) formations [53]. Jatta Gypsum is the oldest formation, with evaporite origin overlaying the Bahadur Khel salt deposition; Mami Khel/Kuldana formations are the early clasts of erosion from the Himalayan mountains in the Eocene era. The purple-reddish-brown shale containing the high-iron Murree Formation (Miocene) overlays the Kohat Formation. The Kamlial Formation (Miocene) is mostly greenish-grey sandstone, similar to the Nagri Formation but with a relatively lower shale. The Chinji Formation has claystone lumps with pointed heaps of sandstone/silty clay reddish clasts bearing high ferric oxide content (hematite). The Nagri Formation consists of micaceous sandstone with 50% sandstone and 50% shale. The Dhok-Pathan Formation contains 70% sandstone and 30% clay shale. The various formations of the Siwalk Group are distinguished by gross sandstone percentages, with the Chinji Formation having less than 50% sand and a greater amount of mudstone, the Nagri Formation more than 50% sand, and the Dhok-Pathan Formation, again, less than 50% sand [47]. The differentiation of these formations would rely on compositional variations of quartz, feldspar, mudstone, and heavy minerals and the presence of mica in lithofragments.  
The semiarid climate with outcrop exposures of variable lithological colors and hydrocarbon potential of the area makes the Kohat Plateau favorable for lithological mapping using spectral remote sensing data. However, for automated mapping of these formations through remote sensing, robust ML algorithms and suitable datasets are required to distinguish between subtle variations due to varying colors (due to associated minerals) and compositions of sandstone, shale, and conglomerates (Table 11 in Appendix A).