Variability of Pennsylvanian–Permian Carbonate Associations and implications for NW Pangea Palaeogeography, east-central British Columbia, Canada

Abstract

Pennsylvanian–Early Permian carbonate sedimentation in east-central British Columbia records a complex history of changing environments influenced by evolving palaeogeography and climate. Newly recognized tectonically controlled features affected the distribution and variability of carbonate associations, providing new interpretations for this portion of the NW coast of Pangea. Both a heterozoan (cool-water) and photozoan (warm-water) association were identified on either side of a palaeogeographical high. Cool-water carbonates were located outboard or to the west of this high, an area influenced by upwelling waters. Inboard of this high, a warm, protected sea developed at about 20°N palaeolatitude during the Asselian and Sakmarian. This configuration and palaeolatitude is similar to that of Baja California, Mexico and the Sea of Cortéz, providing a good modern analogue for these deposits where warm-water carbonates grow at latitudes otherwise dominated by cool-water deposits. The warm sea provided a place for a photozoan association to develop during the Early Permian when the low-latitude NW coast of Pangea was dominated by cool-water carbonates.

Carboniferous–Permian conodonts and the age of the lower Cutler Group in the Bears Ears National Monument and vicinity, Utah, USA

“…2020), the Russian Arctic (Sobolev & Nakrem 1996) and in east‐central British Columbia (Zubin‐Stathopoulos et al . 2013). Species within this zonation have included Adetognathus lautus (Bashkirian to lowermost Gzhelian), Adetognathus sp.…”

“…B is upper Gzhelian; however, the taxon is also recognized higher in the Asselian of Arctic and western Canada where it is more common (Henderson 1989; Zubin‐Stathopoulos et al . 2013; Beauchamp et al . 2020).…”

Palaeoenvironments and elemental geochemistry across the Permian–Triassic boundary at Ursula Creek, British Columbia, Canada, and a comparison with some other deep‐water Permian–Triassic boundary shelf/slope sections in western North America

“…These Permian sediments rest unconformably on Mississippian and Pennsylvanian strata, including carbonates of the Mattson Formation, interpreted as mid‐ramp, sub‐thermocline environments, at water depths of 100 m or more (Matheson et al, 2016) (Figure 2B top). A ridge of Mississippian and Pennsylvanian rocks, uplifted in the early Permian, separated the deeper cooler sediments of the Ishbel Trough from the shallow warm‐water Permian carbonates of the Peace River Basin (Gibson & Edwards, 1990; Zubin‐Stathopoulos et al, 2013) (Figure 2B bottom). The succeeding Lower Triassic blankets these structures and shows apparent westward deepening facies changes (Gibson & Edwards, 1990; figure 16.7).…”

Evidence of warm climate during late Sakmarian–early Artinskian in Posht‐e Badam Block, Central Iran and its paleogeographic implication

“…Carbonates formed in shelf environments in different latitudinal belt possess distinctive features which can be used for paleoclimatic interpretation. Recently, shallow‐water carbonates have been the interest of many workers for paleoclimate analyses (Huang, Shi, & Jin, ; Weidlich, ; Yan, Liang, & Wu, ; Zubin‐Stathopoulos, Beauchamp, Davydov, & Henderson, ). Skeletal associations in carbonates are reliable features to distinguish between warm from cool and cold water carbonates.…”