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the continental plates began to pull apart, rupturing along fault lines roughly parallel to the present-day contin-
ental margin of the eastern seaboard. Rift valleys, similar to East Africa's Great Rift Valley, formed as blocks
subsided along fault lines from Nova Scotia to South Carolina. These valleys became sedimentary basins (the
so-called Newark supergroup), which began to fill with material being eroded from the now-ancient Ap-
palachian mountain chain.
Throughout the Triassic (248-200 million years ago), sediments continued to pour into these basins. Today,
two of the northerly basins are exposed in the Connecticut River Valley of Connecticut and Massachusetts and
the Bay of Fundy region. Rains of monsoon intensity swelled rivers that carried coarse sediments from the
Nova Scotia highlands into the Fundy Basin and lakes occupied the basin floor and finer bottom sediments
piled up to impressive thicknesses—1,000 meters (3,300 feet) in places, today preserved as red sandstones
brilliantly visible along the shores of the Bay of Fundy.
As the Jurassic Age succeeded the Triassic, 200 million years ago, the continental rifting process became
more intense, further stressing the already weakened crust. Molten magma spewed from fissures in fiery lava
fountains and spread over the red sandstones to form Nova Scotia's North Mountain, which stands guard over
the south shore of the bay. This volcanic activity accompanying the breakup of Pangaea was perhaps the most
widespread that has ever occurred. Volcanic rocks have been found on the margins of Pangaea from Brazil to
France and from the Bay of Fundy to Morocco.
It was during this tumultuous time in Earth's history that dinosaurs emerged as the dominant animal group,
and the rift valleys of the eastern seaboard contain a unique record of the very dawn of these “terrible lizards.”
It is unusual to find trackways and bones together, simply because the conditions for their preservation usually
differ. In the Fundy Basin, however, there are abundant bones to match the trackways. Together, they tell a
story of the demise of one group of reptiles and the takeover by another, due to yet another extinction event at
the Triassic-Jurassic boundary 200 million years ago.
The super-continent Pangaea began to break up in the late Triassic, 225 million years ago, giving birth to the Atlantic.
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