Name Blockhouse shale here applied to dark-gray calcareous shale with thin beds and lenses of dark-gray dense limestone in Blockhouse quad., Blount Co., TN. Thickness ranges from 150 to 950 ft. In southwestern part of Tellico-Sevier belt, these fine-grained rocks are partly replaced by fine- to coarse-grained Toqua sandstone member (new), which underlies unnamed shale member. Thin argillaceous limestone forms basal member, and term Whitesburg limestone member is applied to it. Overlies Lenoir limestone; underlies Tellico formation. Blockhouse shale as defined in this report was included by Keith (1895: U.S. Geol. Survey Geol. Atlas, Folio 16) and Rodgers (1953) in lower part of Athens shale.

Source: GNU records (USGS DDS-6; Reston GNULEX).