'Brief' ice age actually lasted 30M years

LEICESTER, England, June 18 (UPI) -- British scientists have determined an ice age occurring about 440 million years ago that's been regarded as a brief period actually lasted 30 million years.

University of Leicester geologists said their findings suggest that during the ancient ice age, global warming was curbed through the burial of organic carbon that eventually led to the formation of oil -- including the "hot shales" of North Africa and Arabia that constitute the world's most productive oil source rock.

The ice age has been named "the Early Palaeozoic Icehouse" by university geologist Alex Page and his colleagues in a paper published as part of a collaborative project between the University of Leicester and the British Geological Survey.

The researchers said the ice age occurred during the Ordovician and Silurian Periods, part of the Early Palaeozoic Era, in an interval that saw a major diversification of early marine animals including trilobites and primitive fish, as well as the emergence of the first land plants.

Page presented his findings Wednesday during a lecture series at the university.