Geology and Minerals
The Hantan (Korean: 한탄강) is a river flowing from Pyonggang County, North Korea across the border through Gangwon and Gyeonggi provinces in South Korea. It is a tributary of the Imjin River, which eventually joins the Han River and empties into the Yellow Sea. The Hantan River is a popular site for white-water rafting.
Calcium sulfate.
Elaterite Butte.
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