Mesoproterozoic

The Mesoproterozoic Era is a geologic era that occurred from 1,600 to 1,000 million years ago. The Mesoproterozoic was the first period of Earth's history of which a respectable geological record survives. Continents existed in the Paleoproterozoic, but we know little about them. It is noteworthy that the continental masses of the Mesoproterozoic are more or less the same ones that are with us today.

The major events of this era are the breakup of the Columbia supercontinent, the formation of the Rodinia supercontinent, and the evolution of sexual reproduction.

This era is marked by the further development of continental plates and plate tectonics. The first large-scale mountain building episode, the Grenville Orogeny, for which extensive evidence still survives, happened in this period.

This era was the high point of the Stromatolites before they declined in the Neoproterozoic.

The era saw the development of sexual reproduction, which greatly increased the complexity of life to come. It was the start of development of communal living among organisms, the multicellular organisms.

It was an Era of apparently critical, but still poorly understood, changes in the chemistry of the sea, the sediments of the earth, and the composition of the air. Oxygen levels had risen to perhaps 1% of today's levels at the beginning of the era and continued rising throughout the Era.

Clearly the era did see large quantities of organisms in at least some areas at some periods: The EIA/ARI Technically Recoverable Shale Oil and Shale Gas Resources: An Assessment of 137 Shale Formations in 41 Countries Outside the United States of June 2013 estimated around 194 trillion cubic feet of gas in place (ca. 44 trillion recoverable) and around 93 billion barrels of oil in place (ca. 4.7 billion recoverable) in the Lower Kyalla and Middle Velkerri formations alone of the Beetaloo Basin in Australia's Northern Territory.

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