Structural relationship between the Karakoram and Longmu Co fault systems, southwestern Tibetan Plateau, revealed by ASTER remote sensing

Abstract

The western margin of the Tibetan Plateau is defined by the NE-striking, sinistral Longmu Co fault system and the NW-striking, dextral Karakoram fault system. The region of convergence of these two systems is remote and politically sensitive, precluding systematic geologic mapping in the field. As a consequence, there is considerable controversy regarding the relationship between these regionally important structural features. Analysis of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) multispectral data and validation with field mapping provide new insights via the production of a lithologic map. Detailed analysis of the ASTER data shows that the two fault systems do not intersect but instead become parallel. Additionally, the geometry and sense of motion of the two fault systems imply that they are acting as a conjugate fault pair, in conjunction with the normal Angmong fault system, allowing for the extrusion of Tibetan lithosphere toward the east. GEOLOGIC SETTING The remote Ladakh Himalaya and adjacent Tibet (Fig. 1) feature several major tectonic structures. The Bangong, Shyok, and Indus-Yarlung suture zones mark the closure of ocean basins during the accretionary evolution of Tibet and the culminating event of India-Eurasia collision (e.g., Gansser, 1964; Yin and Harrison, 2000). The Karakoram fault system marks the southwestern margin of the Tibetan Plateau (e.g., Armijo et al.

Closure of India–Asia collision margin along the Shyok Suture Zone in the eastern Karakoram: new geochemical and zircon U–Pb geochronological observations

“…This intersection has resulted in the formation of an extensional detachment system (Fig. 1c) (van Buer et al 2015;Bohon et al 2018). One can observe the extensional and strike-slip deformationrelated features of these fault systems in the field only within a narrow zone of 5-10 km in the vicinity of the Muglib strand of the KF (Figs 1c, 2g).…”

Tectonic Control Over Shallow Crustal Exhumation Across the India‐Asia Convergent Margin

“…The Arganglas metamorphics consist of post‐India‐Asia collisional metamorphic rocks in the vicinity of the Muglib strand of the KF. These rocks lie in the footwall of the Angmong normal fault system which emerges near the juncture of the Longmu‐Ghoza Co and KF systems (Figure 1b; Bohon et al., 2018; Van Buer et al., 2015). These high‐grade metamorphic rocks are exposed to the north of the KTZ along the upper Shyok Valley within the study area (Figure 1b).…”