The outcrop located behind this limestone processing plant shows white limestone in the mudstone and sandstone strata. Limestone is distributed in and around this area, and has long been mined locally. It is composed of coral fragments and other forms of fossilized warm-water marine life that accumulated on the sea floor and hardened over a long period of time. Limestone is found in the area despite the absence of coral in the cold seas around Hokkaido because it was brought to the area slowly on an oceanic plate from far-off southern seas thousands of kilometers away.

This limestone plant produces fertilizer, livestock feed, industrial lime and other output from limestone (and minerals extracted from limestone) mined previously at the outcrop behind the plant but today from other mines in and around Samani.