Wednesday, August 15, 2007

China Stamp: 2007-23

China Stamp
Name: Tengchong Volcanic Geothermal Area
Number: 2007-23T
Issue date: 2007 August 18th

The Tengchong volcanic district, located in southern China near the border with Burma (Myanmar), was active during five periods ranging from the early Pliocene to the Holocene. Three main stages prroduced Pliocene to mid-Pleistocene basaltic rocks, mid- to late-Pleistocene silicic pyroclastic rocks, and Holocene basaltic andesites. The youngest volcanism in the 600 sq km volcanic field occurred in two stages during the early and late Holocene. Volcanic cones at the northern end of the field are sparsely vegetated and have clearly visible lava flows. Three basaltic-andesite centers, Dayinshshan, Maanshan, and possibly Heikongshan, are of Holocene age. An unconfirmed explosive eruption took place in 1609, and there are unconfirmed reports of eruptions in the Qing Dynasty (1644-1911). The Tengchong district is the site of active geothermal fields, the largest and highest temperature of which is the Rehai geothermal field. More than 20 hydrothermal eruptions have occurred at the Rehai geothermal field since 1993.

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