Erosion on the floor of the English Channel is revealing the remains of a busy Stone Age settlement, from a time when Europe and Britain were still linked by land, a team of archaeologists says.
The site, just off the Isle of Wight, dates back 8,000 years, not long before melting glaciers filled in the Channel and likely drove the settlement's last occupants north to higher ground.
"This is the only site of its kind in the United Kingdom," said Garry Momber, director of the Hampshire and Wight Trust for Maritime Archaeology, which led the recent excavations. "It is important because this is the period when modern people were blossoming, just coming out of the end of the Ice Age, living more like we do today in the valleys and lowlands."
Lobsters mucking around the seabed at the site about 10 years ago revealed a cache of Mesolithic flints, prompting further excavations that uncovered two hearths (ancient ovens) dangling precariously from the edge of an underwater cliff.
Burnt wood fragments gouged with cut marks and a layer of wood chippings were found lying under 35 feet of water during the latest dig. Divers brought the material to the surface still embedded in slabs of the sea floor that were carried up in specially-designed boxes, which were then pieced back together and examined and dated in the lab.
We now have unequivocal evidence of human activity at the site," Momber told LiveScience. "There were people here actively making stuff and being quite industrious."
At 8,000-years-old, the settlement is the only underwater Mesolithic site in Britain, though it is probably part of a much larger area of occupation yet to be uncovered, Momber said.
As the climate began to warm up near the end of the Ice Age about 10,000 years ago, people were moving into Northern Europe and settling down in the many river valleys left behind by melting glaciers, Momber explained. Many of the valleys, such as the ones now beneath the English Channel, were eventually inundated completely when temperatures returned to normal.
"A good chunk of the material left behind from this cultural period is eventually going to be found underwater," Momber said.
Underwater sites better preserved
Despite the logistical problems of underwater archaeology, the Isle of Wight site and others like it are usually better preserved than their counterparts on land, Momber said.
When the floodwater rose slowly in the English Channel, it deposited layers of silt atop the settlement, encasing it in an oxygen-free environment that preserves even organic materials such as wood and food.
Aztec Offerings Found in Bottom of Mexico Lake
MEXICO CITY - Archaeologists diving into a lake in the crater of a snowcapped volcano found wooden scepters shaped like lightning bolts that match 500-year-old descriptions by Spanish priests and conquerors writing about offerings to the Aztec rain god.
The lightning bolts - along with cones of copal incense and obsidian knives - were found during scuba-diving expeditions in one of the twin lakes of the extinct Nevado de Toluca volcano, at more than 13,800 feet above sea level.
Scientists must still conduct tests to determine the age of the findings, but the writings after the Spanish conquest in 1521 have led them to believe the offerings were left in the frigid lake west of Mexico City more than 500 years ago.
Lightning bolt scepters "were used by Aztec priests when they were doing rites associated with the god Tlaloc," said Johan Reinhard, an anthropologist and explorer-in-residence for National Geographic Society who took part in more dives Thursday at the Lake of the Moon. "We think it is pretty clear that the Aztecs considered this one of the more important places of Tlaloc."
The research, which also involves the volcano's Lake of the Sun, is being led by Mexico's National Institute of Anthropology and History. Stanislaw Iwaniszewski, an archaeology professor at the institute, said Aztec iconography often associates Tlaloc with lightning bolts.
"They were left in the lake to bring rain storms," Iwaniszewski said. Copal incense was burned to form "clouds," and sharp spines from the maguey cactus - which does not grow at that altitude - indicated worshippers brought them there to draw blood from themselves as part of the sacrifice.
Luis Alberto Martos, the institute's director of archaeological studies, said other artifacts found in the clear 32-degree waters of the lake indicate the ritual may have started about 100 B.C. - long before the Aztecas settled in the area in 1325.