What are Stromatolites

Question

What are stromatolites?
A) fossil Nautilus shells formed by deposits of hydroxyapatite
B) FeO in banded iron formations
C) bulbous masses of layered CaCO3accreted by microbial mats
D) accumulations of fossil trilobites
E) fossils from the Hadean eon

Accepted Answer

Stromatolites are bulbous masses of layered CaCO₃ accreted by microbial mats. They are often found in shallow marine environments and represent some of the earliest evidence of life on Earth.