Fig. 4: The impact of tectonics on valley-floor widths.
From: Himalayan valley-floor widths controlled by tectonically driven exhumation
a, Illustration of valley-floor width across part of the Narayani basin in central Nepal, where line width is scaled by valley-floor width (widths are scaled up for visibility), and line colour represents channel steepness (ksn). The dashed lines show the main structural boundaries. Note the presence of glacially widened valleys in the Greater Himalayan Sequence, and the distinct valley widening and flattening to the south of the physiographic transition (PT) within the LHS. M, Marsyandi river; BG, Budhi Gandaki River; T, Trishuli river. b, Median valley-floor width (black line, n = 81,208) and exhumation rate derived from thermochronometry24 (blue line, n = 218) binned by 0.1∘ latitude across the region shown in a, showing valley narrowing and rapid exhumation to the north of the PT at the location of the MHT mid-crustal ramp. The shaded areas show the range between the 25th and 75th percentiles. The points show the exhumation rate samples where the error bars represent the 1σ uncertainty in exhumation rate. c, Schematic cross section across the region in a showing the location of the mid-crustal ramp within the MHT (modified from ref. 48).
