Mississippian Rocks of Meramec Age Along Alcan Highway, Northern British Columbia

Abstract

Mississippian rocks are exposed at many places along the Alcan Highway in northern British Columbia from Mile 381 along the Tetsa River northwestward beyond the Liard River crossing. They consist of gray, slabby, silty limestone beds rhythmically interbedded with soft silty calcareous shales. The upper part of the section becomes thin-bedded and on weathered exposures appears as dark green chert. Maximum sections approach 350 feet in thickness. Analysis of the fauna shows the abundant occurence of Dictyoclostus inflatus var. coloradoensis, Spirifer arkansanus, Marginifera adairensis, Leiorhynchus carboniferum, and Deltopecten batesvillensis. This fauna is early Meramec in age and can be directly correlated with some part of the Calico Bluff section in Alaska and with the oorefield formation of the Arkansas Ozark section. No faunas of Kinderhook or Osage age occur along the Alcan Highway.