Thrombolite Walking Trail

The tiny town of Flower’s Cove on Newfoundland’s Great Northern Peninsula is one of only two places in the world where the fossilized remains of some of the Earth’s oldest and most primitive life forms can be found. Lining the shoreline of this tiny saltwater Cove are thrombolites — gray, bun-shaped rock formations estimated to be 650-million-years-old. Their name means “clotted structure.” Thrombolites are thought to be the planet’s first living creatures to release free oxygen, and they predate dinosaurs by at least 225 million years.

The thrombolytic formations are about three to four meters in diameter. Although some have broken over time, most have a circular center surrounded by pie-shaped wedges. Often described as “living rocks,” they were created by prehistoric unicellular microorganisms depositing layers of calcium carbonate leached from the surrounding water. The results were solid grey structures resembling flattened boulders. Interspersed among the formations are glacial erratics, darker-colored round rocks deposited by the Pleistocene glacier. 

The thrombolites’ surfaces have a faint, irregular print or pattern, and lichens adhere in random spots. The furrows etched into the surfaces might be drainage channels or cracks caused by the ebbing and flowing of tides. The larger thrombolites may be several amalgamated communities. Some of the younger thrombolites have burrowing tunnels made by prehistoric metazoan organisms. 

The thrombolites can be reached from a short walking trail after crossing the picturesque red and white wooden “Marjorie’s Bridge” via a boardwalk. Across the bay to the south is another large collection of the formations.