Thrombolites at Flower's Cove

Flower's Cove has one of only two known fossilized microbial colonies known as thrombolites (the other is in Shark Bay, Western Australia). They form impressive round shaped mounds that look a bit like fossilized coral heads.

From the sign explaining there formations:

These are critically endangered microbial structures. Thrombolites-building micro-organisms resemble the earliest forms of life on Earth. These organisms were the only known form of life from 3.5 billion to 650 million years ago. These are some of the earth's most primitive life forms.

Thrombolites (meaning clotted structure) are large bun shaped Cambrian mounds weathering out of flat lying dolostones. They were the growth form of millions of tiny algae and bacteria.

These structures are not exactly fossils, but they are evidence for biological activity. These unicellular critters have left a good size trace of their existance in the fossil record. Thrombo, meaning clotted, indicates an internal structure without lamination.

The darker colored, more rounded boulder is a glacial erratic brought here during Pleistocene glaciation. The furrows, that contain mud-cracked material and radiate from the centre and down the sides, may be drainage channels.

These organisms are thought to have thrived in the tidal and subtidal zone of a warm, very salty sea, some being exposed at low tide, and covered at high tide, thus explaining the mud cracks.Read more