The Himalayan Geothermal Belt (HGB) is a region that extends for through India, Tibet, Yunnan, Myanmar and Thailand, and that contains many geothermal fields.

Location

The Himalayan Geothermal Belt was formed as a result of the collision of the

Indian Plate The Indian plate (or India plate) is or was a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian plate broke away from the other fragments of Gondwana an ...

with the Eurasian Plate, which created the

Himalayas The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of h ...

. The belt is more than wide. The HGB has an extension to the westward that shows in warm or hot springs in the

Peshawar Peshawar is the capital and List of cities in Khyber Pakhtunkhwa by population, largest city of the Administrative units of Pakistan, Pakistani province of Khyber Pakhtunkhwa. It is the sixth most populous city of Pakistan, with a district p ...

region of Pakistan. These are clustered along the Main Karakoram Thrust, Main Mantle Thrust and Main Central Thrust. Some authors consider that the belt extends yet further west and should be called the Mediterranean-Himalayan Geothermal Belt.

Mechanisms

Heat transfer in the HGB mainly occurs in "heat bands", wide, within which there are at least 600 associated geothermal systems. These may be interpreted as segments of slip lines caused by deformation of the ductile crust in the Asian

tectonic plate Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...

. In the eastern Himalayas the heat bands transfer two to three times as much heat as in the western Himalayas. This may be due to the Indian plate rotating in a counter-clockwise direction as it penetrates the Asian plate. The thermal waters in Tibet were thought to be meteoric in origin, and the heat source to be decaying radioactive nuclides. Due to studies in the 1990s and deep drilling results it is now thought that the heat source is granite that has remelted to magma due to the collision of the plates. The warmest hot spring in the westward extension at is the

Garam Chashma Garam Chashma (literally: ''Hot Spring'') is one of the many branch valleys of Chitral District, situated in the extreme north-west of Pakistan. It is one of the highest human settlements in the Hindukush ranges with an altitude of almost 2550 m ...

Hot Springs, which emerge from in post-collisional

leucogranite Leucogranite is a light-colored, granitic, igneous rock containing almost no dark minerals. Leucogranites have been reported from a variety of orogenies involving continental collisions. Examples include the Black Hills (Trans-Hudson orogeny ...

s of the

Hindu Kush The Hindu Kush is an mountain range in Central Asia, Central and South Asia to the west of the Himalayas. It stretches from central and eastern Afghanistan into northwestern Pakistan and far southeastern Tajikistan. The range forms the wester ...

Range that date from 20–18 Ma. Reservoir temperatures may be as high as . It is not clear whether the circulation of deep groundwater in this region is driven by topography or by tectonic lateral stress.

Commercial potential

More than 150 of the geothermal fields have the potential to generate energy. There is a binary plant in Thailand that generates 300 kWe from 117 degrees C water. The Yangbajain Geothermal Field is in the Lhasa-Gangdise terrane. It is in an active part of a slip-fault zone of the Nyainqentanglha Mountains and fractured Himalayan granite. A shallow reservoir has temperatures up to , while a deep reservoir has temperatures up to . The first 1 MWe turbine came into operation in September 1977, and capacity had been increased to 25.18 MWe by 1991. As of 2007 another 7 MWe was being generated by seven small plants in Tibet and Yunnan.

References

Sources

* * * * * {{refend Geothermal energy Geology of China