The Waits River Formation (WRF) is a late Silurian to early Devonian limestone containing lesser amounts of phyllite and schist.

The Waits River formation was deposited through normal faulting and back-arc extension in the late Silurian period.

[5] The Waits River formation is composed of interbedded, weathered marble, quartz-muscovite phyllite, slate, mica-schist, quartzite, and siliceous crystalline limestone, with garnet present throughout.

[8] The Waits River Formation has numerous veins throughout that are composed of a variation of quartz, calcite, muscovite, biotite, pyrrhotite, feldspar, and kyanite.

[6][3] In the Salinic orogeny that occurred during the late Silurian, the sedimentation of the Connecticut Valley began during this time with the extension of the crust.