Himalaya is an active fold and thrust belt formed due to continent-continent collision between the Eurasian and Indian plates. It comprises a 3000 km long chain of mountains that span ∼1000 km across, with major boundary thrusts viz., Main Central Thrust (MCT), Main Boundary Thrust (MBT) and the Main Frontal Thrust (MFT). MFT is marked as mountain front and is the most active thrust; however, evidence of tectonic activity along MCT and MBT also exists.

Tectonic activity along MFT created uplifted terraces which now serve as geomorphic archives of past tectonic events. The present study focussed on a glacial-fed river Sankosh that originates in northern Bhutan, and crosses MCT, MBT and MFT before joining the Brahmaputra River in Assam. Due to tectonic uplift, the river shows a deflection at MFT, incising and thus forming four levels of strath terraces. Luminescence chronology, geomorphic studies and analysis of satellite images suggest four levels of terraces T4 (highest level, 195 m asl), T3, T2 and T1 (lowest level, 120 m asl).

The quartz was found insensitive for luminescence dating, and thus fading corrected Infra-Red Stimulated Luminescence (IRSL) ages on feldspar minerals were measured that provided ages of 143-77 ka (T4), 65-36 ka (T2) and 35-14 ka (T1), respectively. The T3 terrace was present only on the right bank of the river and could not be accessed. These ages accord with other studies at the Chalsa and Malbazar, North Bengal (west of the study area) and this regional disposition of similar ages suggest that these formed during glacial-interglacial periods. The strath terraces indicate a time-averaged tectonic uplift with a 0.5 mm/year rate over the past 150 ka.

喜马拉雅是欧亚板块和印度板块大陆-大陆碰撞形成的活动褶皱冲断带。它由 3000 公里长的山脉组成，跨度约 1000 公里，具有主要的边界冲断层，即主中央冲断层（MCT）、主边界冲断层（MBT）和主锋前冲断层（MFT）。MFT标记为山锋，是最活跃的推力；然而，沿 MCT 和 MBT 的构造活动的证据也存在。

沿 MFT 的构造活动创造了隆起的阶地，这些阶地现在作为过去构造事件的地貌档案。本研究重点关注起源于不丹北部的冰川河流桑科什河，在加入阿萨姆邦的布拉马普特拉河之前穿过 MCT、MBT 和 MFT。由于构造抬升，河流在MFT处出现偏转，下切形成四级地层阶地。发光年代学、地貌研究和卫星图像分析表明梯田有四级梯田 T4（最高层，海拔 195 m）、T3、T2 和 T1（最低层，海拔 120 m）。

发现石英对发光测年不敏感，因此测量了长石矿物的褪色校正红外受激发光 (IRSL) 年龄，提供了 143-77 ka (T4)、65-36 ka (T2) 和 35-14 的年龄ka (T1)，分别。T3 露台仅存在于河的右岸，无法进入。这些年龄与北孟加拉邦查尔萨和马尔巴扎尔（研究区以西）的其他研究一致，并且这种相似年龄的区域分布表明这些形成于冰期-间冰期。地层阶地表明过去 150 ka 的时间平均构造隆升速率为 0.5 mm/年。