Out-of-sequence thrust faulting in the Himalaya poses a great challenge to our understanding of the slip distribution on faults, in particular those that are active. The Kashmir Basin in the NW Himalaya is a classic example of out-of-sequence faulting where the geomorphic analysis of tectonic landforms was possible because of a variety of readily available satellite data, including Shuttle Radar Topography, Google Maps, Global Earth, and Global Multi-Resolution Topography. This was augmented with geologic, seismologic, geodetic, and historical earthquake and flood data. The results show the NW extension of the previously mapped SE-dipping Kashmir Basin fault, where newly mapped discontinuous fault traces are freshly broken and back-tilted, and they preserve warped fluvial surfaces in the Quaternary to Holocene succession. The morphology of the basin suggests that it is rising along an active NE-dipping thrust fault. Importantly, two traces of this fault system cut through the course of the Jhelum River, the only river that drains the Kashmir Basin, and movement on the fault has modified its path. Recent movement on the fault potentially caused damming of this river that resulted in flooding of the Kashmir valley during major earthquakes around A.D. 1505 and/or 1886. Such movement likely caused historical drainage reversals, impoundments, and SE tilting, which were previously attributed to some unknown structures under the Pir Panjal Ranges.

Abstract: The Early Permian (290 Ma) Panjal Traps are the largest contiguous outcropping of volcanic (basaltic, andesitic and silicic) rocks within the Himalaya that are associated with the Late Palaeozoic break-up of Gondwana. The basaltic Panjal Traps have compositional characteristics that range from continental tholeiite to ocean-floor basalt but it is clear that crustal contamination has played a role in their genesis. The basalts that show limited evidence for contamination have Sr–Nd isotopes (87 Sr/ 86 Sr i = 0.7043–0.7073; ε Nd (t) = 0 ± 1) similar to a chondritic (subcontinental lithospheric mantle) source, whereas the remaining basaltic rocks have a wide range of Nd (ε Nd (t) = −6.1 to +4.3) and Sr (87 Sr/ 86 Sr i = 0.7051–0.7185) isotopic values. The primary melt composition of the low-Ti Panjal Traps is picritic with mantle potential temperatures (T P = 1400°C to 1450°C) similar to ambient mantle. The silicic volcanic rocks were derived by partial melting of the crust, whereas the andesitic rocks were derived by mingling between crustal and mantle melts. The Panjal Traps initially erupted within a continental rift setting. The rift eventually transitioned into a nascent ocean basin that led to seafloor spreading and the formation of the Neotethys Ocean and the ribbon-like continent Cimmeria.