File:Fossiliferous nonmarine black shale (Cow Branch Formation, Upper Triassic; Route 220 roadcut north of the Dan River, Rockingham County, North Carolina, USA) 1.jpg

English: Fossiliferous nonmarine black shale in the Triassic of North Carolina, USA.

The Newark Supergroup is a thick, geographically-widespread stratigraphic unit in eastern America. It is Late Triassic to Early Jurassic in age and represents sediments and some lava flows that filled up old rift valleys roughly paralleling the modern-day Eastern Seaboard of America. The rift basins formed in the Triassic when the ancient Pangaea supercontinent attempted to break apart, but failed. A successful breakup of Pangaea occurred during the Jurassic. Most of the basin-filling rocks are terrestrial redbeds - hematite-rich siliciclastic sedimentary rocks, such as conglomerate, sandstone, siltstone, and shale, deposited in nonmarine environments.

Seen here is a fossiliferous nonmarine black shale piece - the light-colored object at center looks like an insect wing, but could be a plant fragment (??). The original muddy sediments were deposited in a lake in the Dan River Basin (Danville Basin), a half graben rift valley. The rocks are fossiliferous - seen on this visit were conchostracans, ostracods, vertebrate bones, coprolites, an apparent insect wing, a possible insect egg capsule, and plants.

Stratigraphy: Cow Branch Formation, Newark Supergroup, Upper Triassic

Locality: Dan River North Outcrop - roadcut on the eastern side of north-bound Route 220, just north of the bridge over the Dan River, east of the town of Madison, central Rockingham County, northern North Carolina, USA (36° 23’ 19.25” North latitude, 79° 56’ 27.48” West longitude)

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For more info., see:

en.wikipedia.org/wiki/Newark_Supergroup