Understanding Himalayan Mountain Ranges and Their Boundaries

The Himalayas are a vast mountain system made up of several parallel ranges. These ranges are separated by major geological fault lines or thrusts. Understanding these boundaries helps us distinguish between the different parts of the Himalayas.

Main Boundary Thrust (MBT) in the Himalayas

The question asks about the mountain ranges separated by the Main Boundary Thrust (MBT). The MBT is a significant geological fault line within the Himalayan region. It represents a thrust fault where older rocks are pushed over younger rocks.

Separation of Himalayan Ranges

The main parallel ranges of the Himalayas from south to north are:

• Shivalik Range (Outer Himalayas): The southernmost and youngest range.
• Lesser Himalaya (Middle Himalayas): Located north of the Shivalik Range.
• Great Himalaya (Inner Himalayas): The highest range, north of the Lesser Himalaya.
• Trans Himalaya: Located north of the Great Himalaya, extending into Tibet.

These ranges are separated by specific thrust faults:

• The Shivalik Range is separated from the Northern Plains by the Himalayan Frontal Fault (HFF).
• The Lesser Himalaya is separated from the Shivalik Range by the Main Boundary Thrust (MBT).
• The Great Himalaya is separated from the Lesser Himalaya by the Main Central Thrust (MCT).
• The Trans Himalaya is separated from the Great Himalaya by the Indus-Tsangpo Suture Zone (ITSZ).

Based on these geological boundaries, the Main Boundary Thrust (MBT) is the dividing line between the Lesser Himalaya and the Shivalik Range.

Therefore, the Main Boundary Thrust (MBT) separates the Lesser Himalaya and Shivalik mountain ranges.