The Virtual Rock Kit -

Rock 10: Triassic sandstone

Triassic sandstone is typically composed of sand-sized grains of quartz and feldspar with some mica (muscovite and/or biotite). The rock formed approximately 220 million year ago during the Triassic period during the faulting associated with the breakup of the Supercontinent Pangea.  The faulting formed rift basins that collected sediment from the eroding igneous and metamorphic rock of the surrounding Piedmont.  The sand-sized sediment later turned into the red to maroon colored sandstones common in the Durham Triassic basin.  Silt- and clay-sized sediment later turned into siltstones and mudstones common in the basin.  Rocks associated with the Durham Triassic basin are exposed along the Eno River east of Roxboro Road.


Triassic sandstone sample
Triassic sandstone wet

Please remember that rock and mineral collecting is STRICTLY PROHIBITTED on protected land!



Want to learn more about the geology of the Eno River area?

You may be interested in A Geologic Adventure Along the Eno River - A richly illustrated publication from the North Carolina Geological Survey.