The cavern system holds significant scientific and aesthetic value
and is potentially the largest volcanic grotto in Southeast Asia,
according to Vietnamese and Japanese scientists.
In 2014, the DGMV also conducted a survey of coal reserves under the Red
River Delta, uncovering the location of major coal seams and a coal
reserve of nearly 1.46 billion tonnes in the southeast coastal area of
Tien Hai district in northern Thai Binh province.
Another survey revealed an estimated 4.56 billion tonnes of crude
bauxite ore and 3.13 billion tonnes of laterite ore concentrated in the
Central Highlands.
DGMV Deputy General Director Bui Vinh Kien said the agency will continue
to expand its surveys in 2015 with a focus on exploring uranium ore
deposits in Nam Giang district of central Quang Nam province, bauxite
and laterite ore in southern Vietnam, and coal resources in the Red
River basin.
Geological survey efforts in 2014 revealed substantial discoveries, including the highlighted volcanic cavern system in Krong No district in the Central Highlands province of Dak Nong, the General Department of Geology and Minerals of Vietnam (DGMV) reported.