Arctic Lake Unlocks the Past
A team of scientists has taken cores from the sediments of a Canadian Arctic lake and found an interglacial record indicating two ice-free periods that could predate the Holocene Epoch. The Pingualuit Crater is located in the Parc National des Pingualuit in northern Quebec. The crater formed about 1.4 million years ago.
The lake has no surface connection to other surrounding water bodies, which makes it a prime candidate for the study of lake sediments. The sediment cores contain mostly laminated silts or sandy mud with rock fragments, which is typical of deposits found in water bodies covered by an ice sheet.
Sandwiched in the middle of the silt and mud, the researchers found two distinct and separate layers containing organically rich material that most likely date back well before the Holocene. The samples they found contain the remains of diatoms and other organic material, suggesting that they represent ice-free conditions and possibly interglacial periods.
December 17, 2007 6:26 AM | Category: Technology