Rare Maar volcanic group found in north China's Inner Mongolia
HOHHOT, Jan. 9 (Xinhua) -- A Maar volcanic group has been found in northern China's Inner Mongolia Autonomous Region, consisting of 116 volcanos, each with a crater diameter of more than 50 meters.
A paper on the finding by Professor Ding Yi's team from the Hebei University of Geosciences was published in the latest issue of Geological Review.
Ding said the Maar volcanic crater is the largest in the world in terms of scale and integrity.
The volcanic group in the northern part of Zhuozi County, Inner Mongolia, has more than 100 craters within a radius of 180 square km, mostly 100 to 400 meters in diameter.
Unlike common conical craters above the ground, Maar volcanos are a group of broad and shallow craters in shape like a "plate with wide sides and flat bottoms," making them difficult to identify.
Ding said its formation of the volcanic group dates back between 33 million years and 9.4 million years ago.