Category Archives: Proterozoic

Oxygenation of Earth’s atmosphere may not have required a trigger event after all

Posted on December 14, 2019 by Chris Rowan

In Earth history, there have been 3 abrupt jumps in atmospheric oxygen. A evolutionary or tectonic trigger is usually invoked, but a new study just published in Science suggests all you need is gradual oxidation of earth’s surface plus feedbacks … Continue reading →

Categories: Archean, climate science, deep time, geochemistry, geology, Palaeozoic, past worlds, Proterozoic, society

New at Erratics – the largest meteorite crater in the world

Posted on March 22, 2011 by Chris Rowan

The clinching evidence for the Vredefort dome being formed by an impact did not come from aerial photos, but from under the microscope. Continue reading →

Categories: links, planets, Proterozoic, structures

New at Erratics: from lahar to suevite

Posted on January 26, 2011 by Chris Rowan

In his second post at Earth Science Erratics Simon Wellings reveals a rather interesting deskcrop, collected from Scotland in his youth: Since it was picked up, this rock has changed identities: what was once thought to be a mud flow … Continue reading →

Categories: planets, Proterozoic, rocks & minerals

Snowball Earth no problem for sponges

Posted on August 18, 2010 by Chris Rowan

Evidence from numerous sources seems to be converging to suggest that sponges – the first animals – emerged much earlier than the beginning of the Cambrian, and apparently sailed through severe climatic events in the Cryogenian without much trouble at all. Continue reading →

Categories: fossils, geology, paper reviews, past worlds, Proterozoic