Devonian to Carboniferous continental-scale carbonate turnover in Western Laurentia (North America): upwelling or climate cooling?

Abstract

The Devonian to Carboniferous (DC) transition coincided with a green-to-ice house climatic shift, anoxia, disappearance of lower latitude carbonate banks, and turnover from warm-to-cool water carbonate factories. In western Laurentia, the switch to carbonate factories dominated by cool-water biota was contemporaneous with a tectonically driven palaeogeographic change. To investigate this depositional shift and infer the relative impact of climate vs tectonics, a continental-scale sedimentological and geochemical study was conducted on twelve stratigraphic sections of DC strata from western Canada to southern Nevada (USA). The spatial-temporal distribution of microfacies records the turnover from [i] a Famennian lime mud-rich, shallow warm-water carbonate ramp with low sedimentation rates, mesotrophic conditions and tabular geometry to [ii] Tournaisian to Viséan lime mud-depleted and grainstone dominated cool-water carbonate ramp with anomalous high sedimentation rates, oligotrophic conditions and a pronounced slope. Positive excursions of δ ¹⁸O_carb (+ 2‰ V-PDB) and δ ¹³C_carb (+ 4‰ V-PDB) of Lower Mississippian carbonates likely correspond to the first cooling peak of the Carboniferous-Permian icehouse climate, following carbon withdrawal during black shale deposition during the late Famennian and early Tournaisian. However, late Tournaisian return of photozoan elements and their persistence throughout the Viséan suggests that warmer surface water existed, revealing a decoupling of the lower latitude ocean and the atmosphere. Shoaling of the thermocline was likely a result of cold-water upwelling along an open coast, as the Antler orogen no longer provided an oceanic obstruction to the west. This study shows that carbonate platforms are more susceptible to regional changes than global shifts.

Supplementary information: The online version contains supplementary material available at 10.1007/s10347-022-00653-4.

Keywords: Carbonate; Carboniferous; Climate; Devonian; Laurentia; Upwelling.

Fig. 1

Palaeogeographic reconstruction and main structural elements of Western Laurentia during the Late Devonian (Famennian) and Early Carboniferous (Tournaisian). Note the pronounced deepening and structural inversion of uplifted areas (CMT and PRU) during the Tournaisian. Yellow boxes are names of stratigraphic units for that time interval

Fig. 2

Biostratigraphic correlation of Upper Devonian to Lower Carboniferous litho-stratigraphic units in Alberta, Montana and Nevada modified from Sandberg (1979), Sandberg et al. (1980), Ziegler and Sandberg (1984), Richards et al. (1993) and Johnston et al. (2010). White areas represent hiatus due to non-deposition or erosion. Age in Ma is displayed in the 3rd column from left

Fig. 3

Map showing studied sections along a transect that represents the inferred Devonian to Carboniferous margin of western Laurentia

Fig. 4

Photomicrographs of MF1 from lower Banff Formation. a Laminae and quartz rich layers (TS 3–25, section 3). b Sparse silt-sized quartz grains in a lime mudstone matrix (TS 3–28, section 3). c Brachiopod shell (TS 3–25, section 3). d Arrow points to bioturbation (Helminthopsis isp). e and f Chondrites isp. (Ch) (TS 3–55 and TS 3–56, section 3). g Rhythmic thin beds of the lower Banff Formation at section 3. h White arrows point to mud-rich layers, black arrow points to silt-rich layers (MF1), Gently dipping cross lamination outlined in red

Fig. 5

Photomicrographs of MF2 from lower Lodgepole, Banff and Joana formations. a Calcitized radiolarians (small white spheres) in Lodgepole Formation (TS LP-12,section 8). b Bioturbation in the Lodgepole Formation (TS LP-12, section 10). c Spiculitic wackestone in the upper Joana Limestone (TS PH-78, section 12). d Spiculitic wackestone with echinoderm and bryozoan fragments in the upper Joana Limestone (TS BM-140 and TS BM-153, section 11). e Cherty intervals in the Banff Formation (TS 6–102, section 7). f Organic matter (OM) in the Banff Formation (TS 6–146, section 7). g and h Photographs of outcrops showing the extent of MF2. Thinly-bedded limestone with abundant chert nodules in the lower Lodgepole (h, section 8) and Banff formations (g, section 7)

Fig. 6

Photomicrographs of MF3 (crinoidal wackestone) from Lodgepole and Banff formations. a Crinoidal fragments (TS LP-26, section 8). b Ostracod, bryozoan and echinoderm fragments in a lime mudstone matrix (TS LP-26, section 8). c Fenestrate bryozoan fragment (TS NG-30, section 9). d Bryozoan fragment in wackestone fabric (TS 3–94, section 3). e. Well-preserved pseudo-punctate brachiopod shell (TS 3–89, section 3). f Crinoid and brachiopod debris in storm deposit (TS 3–94, section 3). g and h Unusual occurrences of packstone with trilobite, crinoid and ostracod fragments in the lower Banff Formation (TS 6Lg-4, section 7)

Fig.7

Photomicrographs of grainstone fabric in MF4. a. Crinoidal grainstone in the Pekisko Formation (TS 8–74, section 6). b Crinoidal grainstone with common fenestrate bryozoans in the Joana Limestone (TS Ph-75, section 12). c. Crinoidal grainstone with rare foraminifer Earlandia in the Pekisko Formation (TS 3–108, section 3). d Bryozoan and crinoid fragments in the Pekisko Formation (TS 3–127, section 3). e and f Different stages of dolomitization of crinoidal grainstone with xenotopic and idiotopic dolomite crystals (TS 5–92 and TS 5–93, section 4)

Fig. 8

a and g MF4 in the middle Banff Formation (section 4). b Tempestites consisting of alternations of crinoidal wackestone and packstone in the middle Banff Formation (section 3). c Intact bryozoan and brachiopod in the Banff Formation (section 3). d Crinoidal stems in the Joana Limestone (section 11). e Rhizocorallium. isp. in the middle Banff Formation at section 3. f Erosional surfaces in the middle Banff Formation (section 4). g Erosional contact between MF3 and MF4 at section 6. h Hummocky bedforms and current ripples in the Banff Formation (section 3)

Fig. 9

Photomicrographs of MF5 in the Pekisko Formation. a Algal-crinoidal grainstone with red and green calcareous algal fragments (TS 3–117, section 3). b Fragments of Parachaetetes sp. (TS 8–75, section 6). c Pekiskopora sp. in a packstone (TS 3–104, section 3). d Stacheinaceae and bryozoan (TS 8–93, section 6). e Micritized grains (TS 8–93, section 6). f Silicified idiotopic dolomite (TS 3–124, section 3). g Thickly-bedded hummocky cross-stratified limestone with truncated beds in the Pekisko Formation at Moose Mountain (section 6). Notice the erosional Banff/Pekisko contact (red line)

Fig. 10

Photomicrographs of MF6 and MF7. a and b Oolitic packstone wackestone with green calcareous algae, bivalve and bryozoan fragments in the Palliser Formation (TS 1–5, section 1). c Oolitic intraclast in a bioclastic wackestone with trilobite(?) from the Mission Canyon Formation (TS MC-10, section 8). d Ooid with brachiopod fragment as a nucleus in the lower Banff Formation (TS 8–15, section 6). e Oolitic bioclastic grainstone (TS 8–96, section 6). f. Radial and bimineralic ooids in the Mission Canyon Formation (TS. MC-8, section 8). g Lump, bimineralic ooids and alga Koninckopora sp. fragment in the Mission Canyon Formation (TS MC-12, section 8). h Foraminifera Spinoendothyra sp. (TS 8–96, section 6). i Tangential ooids in the Joana Limestone (TS BM-80, section 11). j Fibrous marine cement rimming radial ooids in the Joana Limestone (TS BM-80, section 11)

Fig. 11

Photomicrographs of MF8. a and b. Peloidal packstone in the Joana Limestone (TS PH-38 and TS PH-40, section 16). c Peloids in the Joana Limestone (TS PH-50, section 16). d Benthic fauna in the Joana Limestone (TS BM-102, section 15). e Girvanella in the Joana Limestone (TS PH-32, section 16). f Elongated oncoid (TS BM-92, section 15)

Fig. 12

Photomicrographs of MF9 and MF10. a Algal packstone in the Palliser Formation (TS P1-12, section 1). b Algal packstone in the Joana limestone (BM-39, section 12). c Algal fragments, foraminifera and ostracod shells in the Palliser Formation (TS 1–10, section 1). d Algal wackestone in the Palliser Formation (TS 1–9, section 1). e and f Wackestone with intact ostracods in the West Range Limestone (TS BM-42, section 11) and in the Palliser Formation (TS P1-11, section 1). g and h photomicrographs of MF10. g Charophytes wackestone in the West Range Limestone (TS BM-54, section 11). h Wackestone with intact gastropods and charophytes in the West Range Limestone (TS BM-54, section 11)

Fig. 13

Photomicrographs of MF11. a and b Fenestral lime mudstone with algal fragments and stromatolitic laminae in the Palliser Formation (TS 1–12 and TS 1–10, section 1). c and d Peloidal packstone and fenestral fabric in the Shunda Formation (TS 8–92 and TS 8–94, section 6). e Ostracod-rich lithoclast (TS 1–9, section 1) in the Palliser Formation. f Dolomite crystals in fenestral lime mudstone in the Shunda Formation (TS 8–93, section 6). g Fenestral mudstone (MF11) in the Shunda Formation outcrop at Moose Mountain (section 6)

Fig. 14

Whole-rock carbon (δ¹³C_carb) and oxygen (δ¹⁸O_carb) isotopes of Tournaisian rocks from Jura Creek, Alberta (Canada) and Bactrian Mountain, Nevada, showing intervals with heterozoan and photozoan assemblages vs isotope excursions

Fig. 15

Generalised depositional models for the late Famennian and Tournaisian to Viséan microfacies and lithofacies of Western Laurentia