Mesoproterozoic Era

The Mesoproterozoic Era is still part of the Proterozoic Eon. It lasted from 1,600 to 1,000 million years ago. This is the first period of Earth’s history which has a fairly definitive geological record. The continental masses of this era were more or less the same ones that exist today, but not necessarily in the same forms.

During this era, the Columbia supercontinent broke up, the Rodinia supercontinent formed, and, oh yeah, sexual reproduction evolved, which greatly increased the complexity of life to come.

Further development of continental plates and plate tectonics took place. This era saw the first large-scale mountain building episode, the Grenville Orogeny. From the maps I’ve see of this mountain range, it could be what produced the Appalachian Mountains and the Ozark Mountains, but it continued down along what is now the Texas Gulf Coast and into northeastern Mexico.

This was the high point of the Stromatolites before they started to decline. Stromatolites are a type of sedimentary rocks created by photosynthetic cyanobacteria when they exuded adhesives, gluing sand and dirt into mats, which eventually bonded together to form rock formations.

During this era, the chemistry of the sea changed, as did the sediments of the earth and the composition of the air. Oxygen levels continued to rise.

I believe this Era has 3 subdivisions, which I will probably study further, just to try to get a sense of what happened when. The problem with using Wikipedia is that the different articles are or can be written by different people, and then don’t always agree. For instance, is this the 2nd time the Grenville Orogeny is said to have happened? I seem to remember it having been mentioned before, because I remember looking at the map of how far it extended.

Another example is that this article said atmospheric oxygen was at 1% of today’s level at the beginning of this era, while another article said it reached 1-2% of today’s levels during a previous period. I suppose that’s not a huge difference, but it does tend to confuse people who are looking for absolute answers. It’s why I only stated that the oxygen levels continued to rise.

Still not ready for colonization, but we’re getting closer!

 

https://en.wikipedia.org/wiki/Mesoproterozoic