Skardu Basin is a northwest-trending intermontane basin along the Indus River in the Karakoram Himalaya Mountains of Pakistan. Seismotectonic domain boundaries in the Karakoram Himalaya commonly cross lithologic and some older structural boundaries. Four major structural-seismotectonic domains exist in the Skardu area: the Himalayan seismic zone, characterized by thrust tectonics; the complex Hindu Kush–Pamir seismic zone; the Skardu quiet zone, characterized by strike-slip, extensional, and rotational tectonics with relatively little seismicity; and the southern edge of Eurasian lithosphere (Tarim–Kun Lun–Tibet) northeast of the Karakoram fault. The Skardu quiet zone is interpreted to be within the Himalayan thrust prism, above an aseismic detachment along which stable sliding or ductile faulting accommodates displacement. Stresses transmitted into the Skardu quiet zone laterally from the Himalayan seismic zone toward Eurasia and perhaps upward from the inferred basal detachment result in gross clockwise rotation, translation to the north-northwest, and a right-lateral sense of shear in the Skardu region. Landsat lineaments defined by major drainages suggest an array of fractures and faults in the Skardu quiet zone. Field data suggest that the lineaments generally reflect distributed shear along myriad small faults rather than displacement exclusively localized on major, discrete fault surfaces. Extensive glacial and fluvial erosion have accentuated trends characterized by relatively dense fracturing and faulting. At its confluence with the Indus at Skardu, the Shigar River flows through a breach that may have originated as a pull-apart structure similar to the pull-apart basin along the upper Sutlej River. The preserved vestiges of the upper Cenozoic Bunthang sedimentary sequence reflect Skardu’s early basin phase. Uplift along the Nanga Parbat–Haramosh syntaxis and along the northeastern margin of the Himalayan seismic zone may have contributed to the ponding of the Indus River in the Skardu Basin during Bunthang time. These axes of uplift may be related to movement of the Himalayan thrust wedge from a region of easy basal slip (Skardu quiet zone) to a region of increased resistance to basal slip (Himalayan seismic zone, or, in the case of the NP-H syntaxis, the Hindu Kush-Pamir seismic areas). Regional uplift within the Skardu quiet zone may reflect thickening of the thrust prism in response to variations in shear resistance along the detachment. Quaternary glacial lake beds located on the floor of Skardu Basin are generally undeformed in the western half of the basin. Local deformation within the lake beds in the eastern half of the basin is probably due to interaction with glaciers.

A 1.3-km-thick section of basin-fill sediments within the Skardu intermontane basin of the Karakoram Himalaya, termed the Bunthang sequence, is predominantly reversely magnetized. Glacial deposits and landforms are closely associated with the Bunthang sequence. This implies that basin filling took place between glacial advances and prior to the present Brunhes normal chron, i.e., between 3.2 and 0.73 Ma. Four major facies interfinger within the Bunthang sequence: glacial facies; lacustrine facies, indicative of periods during which the Indus River was ponded within the basin; aggradational fluvial facies that represent periods during which the gradient of the Indus River was controlled by rising base level downstream; and alluvial fanglomerates that prograde transversely from the basin margin into the basin at different stratigraphic levels. The last facies represents periods of decreased sedimentation by the Indus River relative to alluvial sedimentation from the basin margin. Downstream from the Skardu Basin, the Indus River crosses the Nanga Parbat–Haramosh syntaxis; this is an area of rapid late Cenozoic uplift (as much as 1 cm/yr). Differential uplift of the Nanga Parbat–Haramosh syntaxis relative to its surrounding terrain led to local variations in Indus River gradient. Temporary ponding of the Indus River is inferred to have occurred when the uplift rate of the Nanga Parbat–Haramosh syntaxis exceeded the rate of downcutting by the Indus River. Temporary blockage of the Indus River Gorge through the Nanga Parbat–Haramosh syntaxis by glaciers or by major landslides may also have led to variations in base level. Temporal variations in the gradient and base level of the Indus River downstream from the Skardu Basin, are reflected in the different facies that interfinger within the Bunthang sequence at Skardu.