Geoscience Reference
In-Depth Information
treating, stretches from Long Island to eastern Connecticut, southern Rhode Island, and the inner side of Cape
Cod.
The retreat of the glacier was relatively fast, in geological terms. Cape Cod and islands emerged in just a
few thousand years, between 23,000 and 19,000 years ago. Dramatic changes in sea level accompanied the ad-
vance and retreat of the glaciers. At the global maximum of the Ice Age, so much seawater was tied up in the
glaciers that the sea level was 120 meters (400 feet) lower than it is today, and broad expanses of the continent-
al shelf were exposed beyond the limit of the ice sheet. Occasionally fish draggers dredge up peat, bones, and
teeth as evidence of the life that once existed there. Among the more intriguing signs of this Pleistocene eco-
system are the teeth of mastodon and mammoth, which would have roamed a spruce-clad parkland that is now
submerged continental shelf south of Cape Cod. To the north, Georges Bank in the Gulf of Maine was also ex-
posed and has also yielded mastodon and mammoth teeth. Mammals more familiar to contemporary residents
of the Atlantic coast, such as deer, moose, and bear, also found a niche in this Ice Age world. And northern
species, such as caribou, lived in the shadow of the glacier and followed it north as it retreated, as did their hu-
man hunters.
Caribou followed the retreating glaciers; they were quickly followed by Holocene hunters.
Search WWH ::




Custom Search