Two main vents, Laoheishan (old black mountain) and Huoshhaoshan (fire burn mountain), formed during the 1719-1721 eruption of the Wudalianchi volcanic field, Heilongjiang province, eastern China. Most of the lava was erupted from Laoheishan. This is the only known historic eruption in the volcanic field. Fissures cut through both cones after they formed. This photo shows the Laoheishan crater. Laoheishan is a monogenetic Strombolian cone.
Aa from the 1719-1721 eruption. The eruption produced about 1 cubic km of lava (mostly pahoehoe) and about 0.15 cubic km of pyroclasts.
Scoria layers in the same province. The layers are from an eruption about 500,000 years ago.
Volcanologists study thin slices of rock, called thin sections, under microscopes to determine the mineral composition of lava and pyroclasts. This shows a microphotograph (in plane-polarised light) of glassy leucite basanite from the 1719-1721 eruption.
Sources of Information:
Feng, M, 1982, The eruptions of Wudalianchi volcanoes in China: Volcano News, v. 10, p. 4-5.
Feng, M., and Whitford-Stark, J.L., 1986, The 1719-1721 eruptions of potassium-rich lavas at Wudalianchi, China: Journal of Volcanology and Geothermal Research, v. 30, p. 130-148.
Feng, M., Guo, K., and Wang, F., 1979, Wudalianchi volcanoes in China: Shanghai Sci Tech Publishers, 85 p. Ming Zhang, GEMOC, Macquarie University, New South Wales, Australia
Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.
Whitford-Stark, J.L., 1987, A survey of Cenozoic volcanism on mainland Asia: Geological Society of America Special Paper 13, 74 p.