[11] The Cow Branch Formation is exposed in the Dan River-Danville Basin,[2][4] a narrow half-graben which extends across the border of Virginia and North Carolina in the eastern United States.

It is one of many Triassic-Jurassic rift basins stretching from northeast to southwest in eastern North America, collectively described as the Newark Supergroup.

[5] The type section of the Cow Branch Formation was a former roadcut along Virginia Route 856, in Pittsylvania County southeast of Cascade.

[13] A new lectostratotype was proposed in 2015: a large stone quarry extending across the state line by the Dan River near Eden, North Carolina.

Coarser sediments such as dark grey sandstone are more prevalent to the southeast and northwest, though periodic black mudstone beds are still frequently encountered.

[5] The Cow Branch Formation represents a lacustrine (lake) system in a warm tropical climate, only around 2°[14] to 4°[15] north of the equator.

[3][4] The high frequency of dolomite in the formation indicates that the lake was strongly alkaline, with its water saturated with magnesium supplied from older carbonate rocks in the area.

In addition, the insect-bearing layers nearly lack organic carbon, suggesting that the lakebed was fully oxygenated even at its deepest extent.

[3][4] Sediment cycles are readily apparent in the formation, shifting between the extremes of black microlaminated shale and massive coarse mudstone.

[4] These are identified as Van Houten cycles, a name applied to fluctuating lake depositional conditions throughout the Triassic rift basins of the Newark Supergroup.

[1][6][2] Most of the fossiliferous unit is calcareous black shale, though thin beds of extremely fine siliclastic clay can also be found.

Insect fossils are predominant in microlaminated carbon-poor shale while fish, plants, and coprolites tend to occur among interbedded carbon-rich dolomite, siltstone, and fine sandstone.

[5] Starting in the 1990s, the depositional history of the Newark Basin was recalibrated through a combination of core drilling, radiometric dating, cyclostratigraphy, and magnetostratigraphy.

The result was the Newark astrochronostratigraphic polarity time scale (APTS), a unifying system which provides precise ages for sediment layers within the basin.

[5] Apart from arthropods, other invertebrate fossils from the Cow Branch Formation include (uncommon) Scoyenia burrows and indeterminate unionid bivalves.

In terms of named diversity, dipterans (flies) make up the bulk of the assemblage, despite representing only 1.5% of insect fossils from the Solite Quarry.

In terms of size distribution, the beetle fauna is similar to modern ecosystems, with just over half of all morphotypes between 2 and 4 mm in length.