Indus-Tsangpo Suture Zone
Also called: ITSZ · Topic: Continental Drift, Sea-floor Spreading and Plate Tectonics · NCERT: Beyond NCERT
Meaning
The Indus-Tsangpo Suture Zone (ITSZ) is the join line where the Indian plate met the Eurasian plate. A "suture" is a stitch, and here two plates have been stitched together. The Tethys Ocean once lay between India and Asia. As India moved north, this ocean closed, and the two landmasses welded together along this line. Slices of the old Tethys ocean floor got trapped in the join. These slices are called ophiolites, and they mark the zone today. It matters because it shows exactly where an entire ocean disappeared.
Example
In Ladakh, the Indus river flows along this zone near Leh. Further east, in southern Tibet, the Tsangpo (called the Brahmaputra in India) follows the same line. That is why the zone is named after these two rivers.
Don't confuse with
- Himalayan thrust faults (MCT, MBT, MFT): these lie further south, inside the Indian plate. Along them, slabs of Indian crust are pushed over each other. The suture is the boundary between two different plates.