It has been decided to commence the quaternary at 2.6 million years before present in order to coincide with the beginning of the ice age and thus provide some significance.
Of course, this immediately asks a few questions but then previous lines did the same. I am most interested in establishing an association with the onset of the ice age and the closing of the
I also think ice caps existed provided land was in place at the poles. It should now be possible to map land location somewhat, leaving room for crustal adjustments if any occurred. Land that straddled the poles deep in time should then show signs of such ice caps.
One thing though is of interest. Both the Antarctic cap and the Northern cap were intact for a very long time. The sea level was much lower as a result. I would like to determine it this effected the edge of the continental shelf in any way. It should not have, yet there is a coincidence there that is at least tantalizing
I think that we know enough to speculate on these matters safely and it may turn out that we can do a goods job of piecing together a proper history of polar and mountain glaciations. We know volcanoes hit heights of 10,000 feet. We also know that outside of the compression zones of the Andes and parts of the Alaskan Arc and the
It is plausible that normal mountain building does not get much beyond 10,000 feet, and there is certainly plenty of that once you accept lower elevations.
Date of Earth's Quaternary age revised
by Staff Writers
The International Commission on Stratigraphy says it has revised the date of the start of Earth's prehistoric Quaternary Period by 800,000 years.
The London-headquartered commission -- the authority for geological science -- decided to end decades of controversy by formally declaring when the Quaternary Period started. The Quaternary age covers both the ice age and moment early man first started to use tools.
Researchers said Earth's history during the 18th Century was split into four epochs, Primary, Secondary, Tertiary and Quaternary. Although the first two have been renamed Paleozoic and Mesozoic, in that order, the second two have remained in use for more than 150 years.
"It has long been agreed that the boundary of the Quaternary Period should be placed at the first sign of global climate cooling," said
In 1983 the boundary was fixed at 1.8 million years, a decision which sparked argument since that point had no particular geological significance.
"For practical reasons such boundaries should ideally be made as easy as possible to identify all around the world. The new boundary of 2.6 million years is just that," Gibbard said.
The decision is detailed in the Journal of Quaternary Science.