The Horlick Formation is a fossiliferous, predominantly marine succession of interbedded sandstone and mudstone that crops out along a prominent escarpment in the Ohio Range. The formation buries a relatively level wave-cut platform eroded across a basement granitoid, and is nowhere more than 56 m thick due to subsequent Permo–Carboniferous glacial erosion.

The sediments have been described in terms of nine lithofacies (Bradshaw & McCartan 1983, McCartan & Bradshaw 1987), that were renamed in conjunction with the establishment of six ichnocoenoses (Bradshaw et al. 2002). An abundant but relatively limited shelly fauna was described by Doumani et al. 1965 and Bradshaw & McCartan 1991.

The six ichnocoenoses within the Horlick Formation have been used in palaeoenvironmental interpretations (Bradshaw et al. 2002). Catenarichnus is an important element and name bearer for one of these ichnocoenoses. Detailed descriptions of the remaining ichnofauna will be described in a separate paper.