The Earth is more than 4.5 billion years old, and for the first 2 billion years of its existence, the atmosphere was largely oxygen-free. Then, theGreat Oxidation Eventoccurred. It's not known precisely how this happened, or exactly when, but it's generally believed thatcyanobacteria ...
Walker, Mike, Johnsen, Sigfus, Rasmussen, S.O., and others, 2009, Formal definition and dating of the GSSP (global stratotype section and point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records: Journal of Quaternary Science, v. 24, p. 3...
Geologists have a bit of awkwardness in their language in talking about the deep past: distinguishing dates in the past fromdurationsor ages. Ordinary people don't have a problem with the weirdness of historical time—in 2017; we can easily say that an event in B.C.E. 200 happened 2216 ...
Ellis, W. LMcKeown, F.A., Dickey, D.D., and Ellis, W.L., 1970, Preliminary report on the geologic effects of the Faultless event: U.S. Geological Survey report USGS-474-65, 20 p.McKeown, F. A., Dickey, D. D., and Ellis, W. L., 1970, Preliminary report on the geologic...
North Africa is noteworthy for having a great diversity of geology and mineral resources. Geologically, the region contains numerous terranes that contain rocks ranging in age from Archean to Quaternary, including diverse igneous, sedimentary, and metamo
The Earth is more than 4.5 billion years old, and for the first 2 billion years of its existence, the atmosphere was largely oxygen-free. Then, theGreat Oxidation Eventoccurred. It's not known precisely how this happened, or exactly when, but it's generally believed thatcyanobacteria ...
Celebrate the third annual Geologic Map Day! On October 17, as a part of the Earth Science Week 2014 activitiesUSGS
The Earth is more than 4.5 billion years old, and for the first 2 billion years of its existence, the atmosphere was largely oxygen-free. Then, theGreat Oxidation Eventoccurred. It's not known precisely how this happened, or exactly when, but it's generally believed thatcyanobacteria ...
Then, the Great Oxidation Event occurred. It's not known precisely how this happened, or exactly when, but it's generally believed that cyanobacteria in the ocean began pumping out enough oxygen to alter the atmospheric composition of the planet. Single-celled organisms first appeared on ...
Then, the Great Oxidation Event occurred. It's not known precisely how this happened, or exactly when, but it's generally believed that cyanobacteria in the ocean began pumping out enough oxygen to alter the atmospheric composition of the planet. Single-celled organisms first appeared on...