posted on Mar, 27 2010 @ 11:52 PM
26 March 2010
The end-Ordovician mass extinction was caused by a major ice age and wiped out 85 per cent of marine life, 445 million years ago. Now scientists are
using the carbon and osmium composition of shale rocks to find out more about this glaciation and why was it responsible for the extinction.
Although not as famous as the disaster that spelled the end of the dinosaurs, the end-Ordovician event was one of the world's biggest mass
'At the end of the Ordovician period, England was part of the tropical continent of Avalonia-Baltica, whereas Scotland was linked to North America on
the other side of the Iapetus Ocean,' says Alexander Finlay, a PhD geochemistry student based at the University of Durham.
An artist's impression of an eroded Ordovician (490 to 443 million years ago) volcano and shore line near Builth Wells, Powys.
445 million years ago, I am assuming that civilizations has been wiped out numerous times, doesn't seem possible that they could go back that far.
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million
years ago (ICS, 2004). It follows the Cambrian Period and is followed by the Silurian Period. The Ordovician, named after the Welsh tribe of the
Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing
the same rock beds in northern Wales into the Cambrian and Silurian periods respectively. Lapworth, recognizing that the fossil fauna in the disputed
strata were different from those of either the Cambrian or the Silurian periods, realized that they should be placed in a period of their own.
Here is another interesting site, not able to copy anything but very interesting read and graphics.
[edit on 28-3-2010 by Aquarius1]