The New Jersey
Geological
Survey recently discovered stromatolites providing the earliest
indications of ancient biological activity in what would one day become
New Jersey.
Stromatolites were discovered in the 1.2
billion-year-old Franklin
Marble from the New Jersey Highlands. Stromatolites are the fossilized
remains
of colonies of cyanobacteria that often have a characteristic
dome-shaped
laminated structure. The lamination's are thin mats that were
constructed
by the microorganisms as they trapped fine grains of calcium carbonate
on
their sticky filaments. A new organic mat was then constructed over the
sediment,
trapping another layer of sediment and producing the next lamination.
The
Franklin Marble was formed from limestone deposited in a marine (ocean)
environment during the Precambrian Era.
 | Paleogeography: Rodinia,
the oldest supercontinent for which we have some record, formed during
the middle Proterozoic (~ 1100 million years ago) with North America in
the center, South America to the east, and Australia and Antarctica to
the west. When the Panthalassic Ocean
formed about 750 million years ago, Rodinia was split into two parts.
One part (North America) moved south, crossing the pole, while the
other (Antarctica, Australia, India, Arabia, and parts of China) headed
toward the North Pole. By the end of the Precambrian (~ 600 million
years ago), these two parts collided with the newly formed Congo craton
(north-central Africa) and formed the supercontinent Pannotia.
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