Older clastic strata of the Porcupine River sequence of Brosgé and Reiser (1969)

Unit symbol: Pzpr
Age range lower Paleozoic (458.4 to 382.7 Ma)
Lithology: Sedimentary
Group name: Clastic and carbonate rocks of the Yukon Flats Basin
Light-gray, fine-grained orthoquartzite, pyritic laminated quartzite, quartz-rich siltstone, and olive micaceous shale at least 600 m thick. Also includes brown-weathering, dark-gray, silty micaceous shale and fine-grained, thin-bedded, pale yellow ferruginous sandstone, which are in an uncertain stratigraphic position relative to the quartzite. Unit is highly sheared along the Coleen River (Brosgé and Reiser, 1969). Similar quartzite, calcareous slate, argillite, and phyllite were mapped as part of the Strangle Woman Creek sequence, which is included here as part of units CPxwn and Dyp. No precise age control exists for these rocks, but they are spatially associated with carbonate rocks of Devonian and older age (unit DCkb)

Source map information

Source map Mull, C.G., and Sonneman, H.S., 1968-1974, Unpublished data
Symbol LPzpCq
Unit name Quartzite, quartzitic sandstone, and phyllite
Description Quartzite, quartzitic sandstone, calcareous schist, schistose sandstone, and phyllite; generally poor exposures in timber-covered hills in southeast corner of quadrangle. Autochthonous/parautochthonous
Lithology Metamorphic

Correlated geologic units

Label DCpu
Description Older strata of the Porcupine River sequence, quartzite; might be equivalent, in part, to Road River Formation graptolitic shale in Yukon
Geologic age Late-Ordovician to Middle-Devonian
Geologic setting Sedimentary, marine, shallow to deep association, undivided
Lithology Form Importance
Quartzose-sandstone < Sandstone < Clastic < Sedimentary Bed Major
Shale < Mudstone < Clastic < Sedimentary Bed Minor
Siltstone < Clastic < Sedimentary Bed Minor