Yangbajain Geothermal Field

Yangbajain Geothermal Field
Yangbajing geothermal power station
Location of Yangbajain Geothermal Field
Country	Tibet, China
Location	Yangbajain, Damxung County, Tibet, China
Coordinates	30°05′51″N 90°30′26″E / 30.097615°N 90.507219°E / 30.097615; 90.507219Coordinates: 30°05′51″N 90°30′26″E / 30.097615°N 90.507219°E / 30.097615; 90.507219
Commission date	1977
Geothermal power station
Type	steam turbo
Wells	8
Power generation
Nameplate capacity	25,181 kW
Annual output	100 GW

The Yangbajain Geothermal Field (羊八井地热田) is a geothermal field near the town of Yangbajain in Damxung County, Tibet, China. The fluid is heated by magmatic activity not far below the surface. It is a tourist attraction and also supplies steam to a major power plant with 25,000 kW capacity. Concerns have been raised that untreated waste water is polluting the river downstream from the power plant,

The Yangbajain geothermal field is in a plateau basin on the southern slopes of the Nyainqentanglha Mountains, near to the Qinghai–Tibet Highway (China National Highway 318) in Damxung County. The Qinghai–Tibet Railway, which terminates in Lhasa, also passes through Yangbajain. The field covers 40 square kilometres (15 sq mi). It delivers natural thermal energy at the ground surface of up to 107,000 kilocalories per second. Yangbajain Geothermal Field is currently the largest proven geothermal field of its nature in China. It has an estimated power generation potential of 150,000 kW.

The Yangbajing Basin lies between the Nyainquentanglha Range to the northwest and the Yarlu-Zangbo suture to the south. The geothermal field is in the central part of a semi-graben fault-depression basin caused by the foremontane fault zone of the Nyainqentanglha Mountains. The SE-dipping detachment fault began to form about 8 Ma. Most of the outcropped rocks are metamorphosed lower Paleozoic rocks, Paleogene volcano-clastic rock series, Neogene conglomerates and loose sediment accumulations from the Quaternary. The fault structures in the region run NE, NW, and nearly N-S. The NE faults are the largest and oldest, and usually have been cut by later fractures and faults. Although there still seems to be frequent magmatic activity, the main stages of magmatic intrusion were the Yanshanian granitic intrusion (88.7 Ma), the Yanshanian dioritic intrusion (88.0 Ma), and the Later Himalayan granitic intrusion (29.7 Ma).