Minami Kantō gas field

The Minami Kantō gas field (南関東ガス田) is a large gas field in Japan, east of Tokyo, in the Chiba prefecture.

Natural gas
The basin holds the most prolific natural gas reserves in Japan, with ultimate gas production of 375 billion cubic meters.

Brine
In addition to natural gas, the field yields a brine rich in iodine. The iodine is extracted in large scale and makes this area the second largest producer after Chile, where the iodine is extracted from the caliche.