Merkur

Merkur was a geological and paleontological natural monument located southwest of the village of Málkov, close to Zelená in the Chomutov District, at an elevation of roughly 360–370 meters above sea level. The site no longer exists in protected form today, but its story remains a striking example of how open-pit coal mining can uncover traces of a world millions of years old — and how quickly nature can undo that same discovery.

Where did the name come from and what was Merkur?

The locality took its name from the nearby Merkur-Libouš open-pit mine, within whose grounds it was situated. The site was first identified in 1960 through exploratory drilling, but it wasn't until the late 1980s, during surface extraction of brown coal, that excavators exposed a roughly one-meter-thick layer holding an extraordinary geological record dating back nearly 18 million years.

What was discovered at the site?

The exposed layer preserved plant remains along with something far rarer: nearly complete or fully intact skeletons of turtles and rodents. All of it came from the shore of a Tertiary-period lake, a shoreline that had remained undisturbed for millions of years until mining operations exposed it. This allowed researchers to reconstruct what the region's natural environment looked like during the Miocene — which plants grew along the water and which animals lived nearby.

Why was the area placed under protection?

Given the uniqueness of the find, the District Office in Chomutov designated the area a natural monument on April 26, 1993. The protected zone covered 3.1931 hectares and sat directly beneath the lower seam of brown coal — something of a paradox, since the site survived thanks to mining activity while also remaining right in its path.

What caused Merkur to disappear?

Starting in 2004, the area began experiencing landslides. Repeated ground movement, most likely compounded by natural erosion processes near the open pit, gradually and ultimately completely destroyed the paleontological site. As a result, authorities formally revoked its protected status on July 9, 2009. Since then, Merkur has existed only as an entry in nature conservation records and in the memory of local researchers.

Frequently asked questions

Can you still visit the Merkur natural monument today? No — the site lost its protected status in 2009 after landslides destroyed the paleontological locality.

What exactly was found at Merkur? A layer of Miocene-era sediment containing well-preserved plant remains and nearly complete skeletons of turtles and rodents, originating from the shore of a former Tertiary lake.

Why was the site discovered in the first place? Thanks to surface brown coal mining at the Merkur-Libouš pit in the late 1980s — its existence had already been confirmed by exploratory drilling back in 1960.

How large was the protected area? Just under 3.2 hectares, established by a decision of the Chomutov District Office in 1993.