These microbial mats created a barrier between the water and the sediment underneath, which was less water-logged than modern sea-floors, and almost completely anoxic (lacking in oxygen).
Estes tapetes microbianos creaban unha barreira entre a auga e o sedimento do fondo, que estaba menos enchoupado de auga que os fondos mariños modernos, e era case completamente anóxico (carente de oxíxeno).