A Mesoproterozoic iron formation

Organomineralization in Mesoproterozoic giant ooids

Ooids are common carbonate particles that are traditionally considered as abiogenically formed by physical and chemical processes in highly agitated environments. Recent studies point to the importance of microbial activities in ooid formation, but more case studies are required to confirm and clarify the roles of microbes and their organomineralization processes. Here we report an integrated p...

Active microbial sulfur disproportionation in the Mesoproterozoic.

The environmental expression of sulfur compound disproportionation has been placed between 640 and 1050 million years ago (Ma) and linked to increases in atmospheric oxygen. These arguments have their basis in temporal changes in the magnitude of 34S/32S fractionations between sulfate and sulfide. Here, we present a Proterozoic seawater sulfate isotope record that includes the less abundant sul...

Mesoproterozoic Calymmian Tintinnids from Central China

Tintinnids are very common in all marine water and even fresh water. The oldest fossils of Tintinnids are not only appeared in Neoproterozoic Era, but also in Mesoproterozoic Calymmian. Eight species of six genera Tintinnids of Mesoproterozoic Calymmian, from Huangmailing Phosphoric Ore in Hubei Province of Central China, are illustrated in this paper. They are the oldest ancestor of Tintinnids...

Iron Sulfide Formation

The Mesoproterozoic – no “boring billion”

The authors show that the Mesoproterozoic (1.6-1.0 bn year before present) was no “boring billion” but a “bustling billion” - not only with Stromatolites and their apex in the Calymmian and Ectasian but also with the presence of multicellular organisms. To make it visible a graphical reconstruction was created. For a long time, it was assumed that there existed no noteworthy biosphere on Earth ...