At the Low Jarvis and Jumar showing a northwest dipping sequence of black shales overlain by volcanic agglomerate and massive chlor- itic andesite is exposed on Jan Still Ridge. Thin bands of quartzite and black shale are interbedded in the andesite. Disseminated sphalerite and pyrite occur within a barite-rich, white tuff horizon, about 1.2 metres thick, which is exposed over 20 metres. Massive sphalerite up to 5 centimetres thick is exposed for several metres in a stratiform horizon above the baritic tuff bed. This horizon strikes 030 degrees and dips 20 degrees northwest, and is terminated to the north by a steep south-dipping, west-trending fault.