Transcript Geological History of Connecticut

 Paleozoic Era (450-250 million years ago) tectonic
plates including Africa and Eurasia collided with the
Proto-North American Plate.
 Super Continent Pangaea was formed
 Small part of the African Plate (Avalonia) collided with
Proto-North America
 Lapetos Ocean was squeezed out from between the
colliding continents
 Continental Rocks of Proto-North America, Avalonia and
oceanic rocks and sediment deformed and metamorphosed
into Granite and Gneisses schists (CT D.E.P. 2009)
 Mountains such as the Appalachians where built
 Mesozoic Era (235 million years ago) plate tectonic
process reversed
 Pangaea began to break apart
 Atlantic Ocean Began to form
 Avalonia was firmly attached to North America
 Rift Basins began to form on each side of the breakup
 The Newark terrain in central Connecticut is the eroded
remains of one of these basins
 Contains 200 million year old sedimentary rocks and intrusions
of basalt from lava flows (CT D.E.P. 2009)
 Glaciation played a major roll
on how Connecticut is shaped
today
 24,000 years ago was the last
glaciation that covered
Connecticut took place
 The Glacier flowed south until
the weather was to warm to
support it’s formation
 Connecticut was covered with
ice for about 5000 years
 The glacier contained large amounts
of rock, sand, and clay (glacial till)
 Large boulders were displaced
(Plucking)
 When the ice melted these materials
were deposited which formed a
terminal moraine
 Terminal Moraine a large pile of rock,
sand, and clay piled up at the edge of
the glacier, marking the boundary of
the glaciers advancement
 Long Island, Fishers Island, Martha's
Vineyard, Nantucket, and Cape Cod
were all formed by terminal moraines
Terminal
Moraine
21,500 –
17,000
years
ago
26,000 – 21,500
years ago
15,500 – 5,000 years ago
17,50015,500
years ago
5,000
years
ago to
present
 http://www.ct.gov/dep/cwp/view.asp?a=2698&q=3232
52&depNav_GID=1707 (2009)