Located within the Arabia–Eurasia collision zone, the Iranian Plateau (IP) constitutes the second largest and elevated collisional plateau on Earth. The IP is predominantly situated on the Eurasian upper plate, has an average elevation of approximately 2 km and is characterized by a crustal thickness of up to 50–60 km, underlain by a thin mantle lithosphere with a lithosphere-asthenosphere boundary at depths of 100–120 km. The surface of the plateau exhibits a contractional basin-and-range morphology, encompassing both internally and externally drained sedimentary basins. Its interior is arid and displays relatively low topographic relief, in contrast to its steep, highly dissected margins, which locally form significant orographic barriers.

Although the uplift of the IP must have occurred after the most recent marine transgression (i.e., post ~17 Ma), several key questions remain unresolved. These include the development of a comprehensive geological model for the plateau, constraints on the timing and mechanisms of surface uplift, and the role of surface processes in shaping, preserving, or locally eroding the characteristic plateau morphology.

This contribution seeks to synthesize existing data and incorporate previously unpublished findings in order to provide an updated overview of the current state of knowledge. It further aims to identify key research challenges that will advance our understanding of collisional plateau evolution.

The western fold-and-thrust belt (FTB) of Pakistan is structurally divided into the Sulaiman FTB in the north and the Kirthar FTB in the south, separated by the Quetta syntaxis. We investigate the spatiotemporal structural evolution of the Kirthar FTB with low-temperature thermochronology (Apatite U-Th-Sm/ He (AHe), Fission track (AFT), and Zircon U-Th/He (ZHe)) age data. Our dataset includes 14 AHe, 9 AFT, and 4 ZHe surface ages, supplemented by 18 AFT, 56 vitrinite reflectance (VR), and 9 Rock-Eval (Ro) samples from foreland wells.

In the Northern Kirthar, partially reset Eocene AHe ages and AFT age of 135 ± 34 Ma, combined with unreset ZHe ages (187.7-424.6 Ma) from Cretaceous samples, indicate shallow burial and preserved signatures of pre-Oligocene uplift. In contrast, Central Kirthar records resetting of Paleocene to Oligocene samples with AHe ages (~6–8 Ma), however; the AFT (~119 ± 43 Ma) and ZHe ages ages (63-433 Ma) show partial resetting, suggesting Late Miocene to Pliocene rock uplift from ~3 km depth. In Southern Kirthar, the westernmost samples yield Oligocene AHe ages of 5.3 ± 1.7 Ma, AFT ages of 23.3 ± 8.3 Ma, and un-reset ZHe ages (202.0 to 390.7 Ma), suggesting burial of ~3 km before exhumation. However, range-front samples show different patterns with a partial reset age (21.2–6.5 Ma) for, hanging-wall Oligocene and footwall Miocene samples (18 Ma). In the Katawaz Basin, deeper burial (~3-5km) is evident in the northern sector, while southern sectors experienced only limited burial, insufficient to reset AHe and AFT ages.

This research focuses on the northwestern segment of the Himalayan foreland belt in Pakistan, the Kohat Fold and Thrust Belt (KFTB), where the style and sequence of deformation since the Miocene differ significantly from the rest of the Himalayas (Robinson et al., 2023; Ghani et al., 2018). Sequentially restored balanced cross-sections, integrated with apatite (U-Th-Sm)/He (AHe) thermochronology, are employed to jointly interpret the deformation history and exhumation pattern in the study region. The preliminary results show that the resetting age of AHe is late Miocene-Pliocene and Pleistocene in the northern and central KFTB respectively, while they are partially reset in the Khisor Ranges the western part of the Range front. In the Surghar Ranges (the central part of the Range front) the ages appear as reset in early Miocene time which is older than the previously reported AHe age (Ghani et al., 2021).

These patterns suggest out-of-sequence deformation and high exhumation in the northern and northwestern KFTB. The variation in low-temperature thermochronological ages along strike in the central KFTB is likely due to salt-tectonics activity in the eastern Kohat and limited toward the western KFTB. The age constraints in the Range front (from Salt Ranges to Khisor Ranges) suggest shallow burial in the east and west and deep burial in the northern segment of the range front (along the Surghar Thrust).

The ongoing apatite fission track thermochronology will provide additional constraints on the spatio-temporal evolution of the region

The western Himalayan fold-and-thrust belt exhibits variable fault kinematics and exhumation patterns. Our thermochronological (AHe) data reveal a broad zone of consistent cooling ages (~4–6 Ma) across the Potwar Plateau and Salt Range. This spatially uniform pattern suggests a temporally limited phase but spatially extended region of synchronous exhumation. We interpret this as deformation localized along a low-friction salt detachment enabling wedge translation on the emergent SRT/HFT without significant internal reorganization. In contrast, the eastern flank of the syntaxis (Kashmir Himalaya) exhibits significantly younger and spatially variable AHe ages (~0.9–7 Ma), with young ages (0.9-3.5 Ma) concentrated in the frontal and rear ends, and older ages in the center. This spatial and temporal variability in exhumation, interpreted along with the geological, geophysical, and geomorphic evidence, suggest that orogenic wedge is segmented, where exhumation is driven by rock displacement along active roof backthrusts in the frontal zone, and internally by out-of-sequence faulting facilitated by focused erosion and reactivation of inherited basement structures. Based on our analyses, we propose that exhumation in the Kashmir Himalayas occurs via distributed, diachronous uplift, reflecting a mechanically heterogeneous and internally reorganized orogenic wedge.This contrasts with the synchronous and spatially uniform exhumation pattern in the western limb. These contrasting patterns and wedge behaviors suggest an asymmetric structural architecture and differing thicknesses of sedimentary parts (salt vs. clastic) in the foreland, modulated by feedback between erosion, fault kinematics, and wedge strength. Understanding this coupling is crucial for unraveling young orogenic wedge evolution and assessing seismic hazard risk.

The arcuate, northward convex Pamir mountains are fringed in the west and north by foreland fold-and-thrust belts forming the External Pamir (EP). In the west, the wide thrust belt occupies the entire Tajik Basin. Towards the northeast, it grades into a narrow, W-E-trending belt along the southern margin of the intermontane Alai Valley which separates the Pamir front from the Tian Shan in the north. In the westernmost Tarim Basin, the thrust belt widens again to form a pronounced northward salient. We present three cross sections to illustrate along-strike variations of the EP in topography, erosion level, stratigraphy, and structure. Possible variables that controlled structural styles and evolution include: (1) Basement rheology and structure: mechanical strength and buoyancy probably increase eastward from Pamir lithosphere forming a steeply dipping continental slab to the rigid Tarim basin. The basement beneath Alai makes a large antiform plunging west- and eastward towards the Tajik and Tarim basins. (2) Pre-Cenozoic structure: in the Tian Shan the Talas-Fergana fault is a major NW-SE-striking discontinuity that was already active in Paleozoic and Mesozoic time and probably links up with large faults in western Tarim. (3) Facies and thickness variations of Mesozoic and Cenozoic deposits: in Alai, multiple décollement levels in Cretaceous and Paleocene rocks favor short-wavelength folding. In W Tarim, few large thrusts splay from a single basal décollement in thick Paleocene gypsum. Cenozoic strata thicken markedly eastward. Mutual influence and feedback between these tectonic-stratigraphic parameters and variations in climate driving erosion intensity is probable.