Elsevier

Precambrian Research

Volume 278, June 2016, Pages 179-206
Precambrian Research

Rifting of Columbia to form a deep-water siliciclastic to carbonate succession: The Mesoproterozoic Pinguicula Group of northern Yukon, Canada

https://doi.org/10.1016/j.precamres.2016.03.021Get rights and content

Highlights

  • The Pinguicula Group siliciclastic and carbonate strata were deposited on low-energy slopes.

  • The Pinguicula Group is an example of a rare deep-water Mesoproterozoic succession.

  • The Pinguicula basin may signify the separation of Laurentia from Australia.

Abstract

The Mesoproterozoic Pinguicula Group (<1.38 Ga) is exposed in the Wernecke and Hart River inliers in northern Yukon, Canada. The Pinguicula Group records deposition of non-cyclic siliciclastic and carbonate strata on low-energy slopes affected by rare high-energy deposits in a tectonically active epicratonic setting. The succession is ∼1.4 km thick at its measured type sections and comprises three newly formalised formations: the Mount Landreville, Pass Mountain, and Rubble Creek formations (formerly units A, B, and C, respectively). The Mount Landreville Formation is a predominantly siltstone succession with minor conglomerate and sandstone deposited below storm wave-base on a relatively gentle slope. The Pass Mountain Formation is a wispy- to planar-laminated carbonate succession deposited on a low-energy slope mostly below storm wave-base and is punctuated by rare high-energy gravity-flow deposits including debrites, grain-flows, turbidites, and micro-turbidites. The Rubble Creek Formation is dominated by repetitive centimetre- to decimetre-scale lime mudstone beds; it is distinguished from the Pass Mountain Formation by abundant zebra texture (an alternating dark grey and white banding caused by late diagenetic or hydrothermal fluid influx) and a lack of sediment gravity-flow deposits.

The Pinguicula Group is the middle of five, unconformity-bounded, Proterozoic stratigraphic successions deposited on the northwestern margin of Laurentia (ancestral North America). The Pinguicula basin was epicratonic and deepened to the south (present coordinates). The basin formed during an amagmatic extensional event that contributed to the break-up of Columbia and the separation of Laurentia from Australia.

Whereas most preserved Mesoproterozoic basins are dominated by shallow-water lithofacies deposited in rift and epicratonic settings, with few deep-water lithofacies preserved, the carbonate strata of the Pinguicula Group provide a rare insight into deeper-water carbonate environments.

Introduction

The evolution of western ancestral North America (Laurentia) from late Paleoproterozoic to Paleozoic time was dominated by the formation of sedimentary basins (Gabrielse, 1967, Fritz et al., 1991, Poole et al., 1992, Link et al., 1993, Norris and Dyke, 1997). Together, these basins record a pattern of repeated lithospheric extension and sedimentary fill separated by long hiatuses. The basinal successions are typified by substantial thicknesses of both siliciclastic and carbonate rocks. Igneous activity, although locally important, was secondary to sedimentation. Activity during the sedimentary hiatuses varied from quiescence to basin inversion, terrane accretion, magmatism, and hydrothermal surges (Eisbacher, 1978, Aitken and McMechan, 1992, Colpron et al., 2002, Thorkelson et al., 2005, Milidragovic et al., 2011, Doe et al., 2012, Furlanetto et al., 2013, Thorkelson and Laughton, in press).

In northwestern Laurentia, the Precambrian sedimentary record consists of at least five intervals of basin formation that span over a billion years (Young et al., 1979, Thorkelson et al., 2005, Macdonald et al., 2012, Medig et al., 2014). The record was divided into three unconformity-bounded successions named sequences A, B and C by Young et al. (1979). Since then, the understanding of sedimentation and other processes in the region has expanded appreciably, and the history of basin formation is now known to be far more complex than previously envisaged. Despite advancements in understanding, the significance of each sedimentary succession in terms of cause, paleogeography, and nature of bounding surfaces remains largely unanswered.

The Mesoproterozoic Pinguicula Group is the third in a series of five sedimentary successions that crop out in extensive Proterozoic inliers of Yukon, Canada. The succession is well exposed in mountainous terrain in northern Yukon over an area of at least 100 × 190 km and as much as 100 × 330 km, depending on the validity of stratigraphic correlations. Its deposition was preceded by deposition and ensuing contractional deformation of the Paleoproterozoic Wernecke Supergroup (Delaney, 1981, Furlanetto et al., 2013), and deposition and uplift of Mesoproterozoic unit PR1 (Medig et al., 2014). The Pinguicula Group was succeeded by the Neoproterozoic Mackenzie Mountains Supergroup and its correlatives, the Fifteenmile and Hematite Creek groups (Thompson et al., 1992, Thorkelson, 2000, Turner, 2011a, Turner, 2011b, Macdonald et al., 2012), and the late Neoproterozoic Windermere Supergroup (Eisbacher, 1985).

Prior to this study, the Pinguicula Group had been mapped and studied at only the reconnaissance level by Green, 1972, Blusson, 1974, Eisbacher, 1981, Abbott, 1997a, Thorkelson, 2000. Without a focused sedimentological study, many questions remained regarding sedimentological and stratigraphic detail, depositional environment, paleocurrents, basin architecture, composition, and age. Accordingly, this study involved detailed mapping, section measurement, detailed petrography, detrital mineral geochronology, and geochemistry. In this paper, the stratigraphic, lithologic, and petrographic data are used to define the stratigraphy of the Pinguicula Group formally and to describe its sedimentological history in terms of environments of deposition, direction of sediment transport, and basin evolution. Particular attention is given to the carbonate rocks in the Pinguicula Group, and comparisons are drawn with Mesoproterozoic carbonate rocks globally.

Section snippets

Geologic setting

The Mesoproterozoic Pinguicula Group, as originally defined, is exposed in the Wernecke inlier (Eisbacher, 1978). Possible correlatives were identified in the Hart River inlier (referred to as the Pinguicula Group by Abbott, 1997b) and Coal Creek inlier (Fig. 1, Fig. 2; as part of the Fifteenmile group; Thompson et al., 1992). The underlying Wernecke Supergroup is estimated to be >14 km thick and includes, from oldest to youngest, the Fairchild Lake Group, the Quartet Group, and the Gillespie

Stratigraphic relationships and descriptions

In the Wernecke inlier, the Pinguicula Group overlies the Gillespie Lake and Quartet groups of the Wernecke Supergroup with angular unconformity (Fig. 2; Thorkelson, 2000). The Mount Landreville Formation also unconformably overlies zones of Wernecke breccia and Hart River sills (Thorkelson, 2000, Medig et al., 2010). Previously, the Hart River sills in the Wernecke Mountains were thought to cut the Pinguicula Group (Thorkelson, 2000, Thorkelson et al., 2005), but an unconformable rather than

Mapping and section measurement methods

The Pinguicula Group was mapped in the Wernecke inlier on 1:50,000 map sheets NTS 106C/11, and NTS 106C/12, south of areas NTS 106C/13 and NTS 106C/14, previously mapped by Thorkelson (2000). Type sections for the Mount Landreville, Pass Mountain, and Rubble Creek formations were measured and described in detail at three different locations (Fig. 3). A detailed section through the Mount Landreville Formation was measured in a creek bed at the PIKA mineral occurrence (Fig. 4, Fig. 5). At this

The Mount Landreville Formation

At the measured section, the Mount Landreville Formation (formerly unit A) is 306 m thick and is predominantly siltstone with minor conglomerate and sandstone (Table 1 and Supplementary Table 1; Figs. 4 and 9a). A 50 cm-thick layer of polymictic pebble conglomerate is the lowest unit in the section (unit 1) and unconformably overlies a zone of Wernecke Breccia (Fig. 9b). The conglomerate is matrix-supported with well-rounded pebble clasts approximately 4–15 mm long. The clasts are composed of

Pinguicula Group Lithostratigraphy, Hart River inlier

In the Hart River inlier, the Pinguicula Group displays similar lithofacies to those in the Wernecke inlier (Table 1 and Supplementary Table 1; see Supplemental Data). One exception is at the measured section, where the Rubble Creek Formation is composed almost entirely of stromatolites.

Reconnaissance mapping of the Pinguicula Group in the Hart River inlier was completed by Abbott (1997b) who described the conformable Mount Landreville, Pass Mountain, and Rubble Creek formations as an

Mount Landreville Formation: deep-water siliciclastic sediment

The Mount Landreville Formation records the onset of basin formation. Polymictic pebble conglomerate at the base of the unit is interpreted as channels cutting into the otherwise sandy substrate in the basin as transgression and submersion of the underlying Wernecke Supergroup, Wernecke Breccia, and Hart River sills progressed. Most of the succession consists of siltstone and calcareous siltstone with planar, parallel lamination. These facies are interpreted to have formed in a deep-water

Tectonic setting of the Pinguicula Group

The Pinguicula Group is the middle of five unconformity-bounded stratigraphic successions deposited on the northwestern margin of Laurentia between the late Paleoproterozoic and the Cambrian (Eisbacher, 1978, Delaney, 1981, Thorkelson et al., 2005, Medig et al., 2014). Together, these successions record repeated episodes of subsidence, marine transgression and clastic-carbonate sedimentation, commonly followed by uplift and erosion. Significant magmatism synchronous with sedimentation did not

Conclusions

  • 1.

    The Pinguicula Group is a siliciclastic and carbonate succession that consists of the newly formalised Mount Landreville, Pass Mountain, and Rubble Creek formations (formerly known as units A, B and C). The succession was deposited on a low-energy, gentle slope that recorded episodic, high-energy, events in an extensional epicratonic basin that deepened to the south (present day coordinates). The majority of the sediment was deposited below storm wave-base, but rare lithofacies deposited above

Acknowledgements

Funding for the project was provided by the Yukon Geological Survey, The Geological Survey of Canada, Northern Scientific Training Program, and an Natural Sciences and Engineering Research Council of Canada grant to Derek Thorkelson. Katherine Hahn, Geoff Baldwin, Tim Peters, Francis Macdonald, and Robbie Dunlop are thanked for their assistance in the field. Dr. Linda Kah and one anonymous reviewer are thanked for their thorough reviews that led to improvements in the quality of this manuscript.

References (110)

  • G. Eisbacher

    Late Proterozoic rifting, glacial sedimentation, and sedimentary cycles in the light of Windermere deposition, western Canada

    Palaeogeogr. Palaeoclimatol. Palaeoecol.

    (1985)
  • F. Furlanetto et al.

    Late Paleoproterozoic terrane accretion in northwestern Canada and the case for circum-Columbian orogenesis

    Precambrian Res.

    (2013)
  • G.J. Gilleaudeau et al.

    Carbon isotope records in a Mesoproterozoic epicratonic sea: carbon cycling in a low-oxygen world

    Precambrian Res.

    (2013)
  • H. Guo et al.

    Isotopic composition of organic and inorganic carbon from the Mesoproterozoic Jixian Group, North China: implications for biological and oceanic evolution

    Precambrian Res.

    (2013)
  • P. Haughton et al.

    Hybrid sediment gravity flow deposits – classification, origin and significance

    Mar. Pet. Geol.

    (2009)
  • L.C. Kah et al.

    Chemostratigraphy of the Late Mesoproterozoic Atar Group, Taoudeni Basin, Mauritania: muted isotopic variability, facies correlation, and global isotopic trends

    Precambrian Res.

    (2012)
  • A. Khudoley et al.

    Sedimentary evolution of the Riphean-Vendian basin of southeastern Siberia

    Precambrian Res.

    (2001)
  • Z.X. Li et al.

    Assembly, configuration, and break-up history of Rodinia: a synthesis

    Precambrian Res.

    (2008)
  • J.F. Lindsay et al.

    A carbon isotope reference curve for ca. 1700–1575 Ma, McArthur and Mount Isa Basins, Northern Australia

    Precambrian Res.

    (2000)
  • A.V. Maslov et al.

    The main tectonic events, depositional history, and the palaeogeography of the southern Urals during the Riphean-early Palaeozoic

    Tectonophysics

    (1997)
  • K.P.R. Medig et al.

    Pinning northeastern Australia to northwestern Laurentia in the Mesoproterozoic

    Precambrian Res.

    (2014)
  • A.B. Nielsen et al.

    The Wernecke igneous clasts in Yukon, Canada: fragments of the Paleoproterozoic volcanic arc terrane Bonnetia

    Precambrian Res.

    (2013)
  • A.V. Nyberg et al.

    Microfossils in stromatolitic cherts from the Proterozoic Allamoore Formation of west Texas

    Precambrian Res.

    (1981)
  • P.Y. Petrov et al.

    Sequence organization and growth patterns of late Mesoproterozoic stromatolite reefs: an example from the Burovaya Formation, Turukhansk Uplift, Siberia

    Precambrian Res.

    (2001)
  • S.A. Pisarevsky et al.

    Mesoproterozoic paleogeography: supercontinent and beyond

    Precambrian Res.

    (2014)
  • B.R. Pratt

    Oceanography, bathymetry and syndepositional tectonics of a Precambrian intracratonic basin: integrating sediments, storms, earthquakes and tsunamis in the Belt Supergroup (Helena Formation, ca. 1.45 Ga), western North America

    Sed. Geol.

    (2001)
  • J.S. Ray et al.

    C, O, Sr and Pb isotope systematics of carbonate sequences of the Vindhyan Supergroup, India: age, diagenesis, correlations and implications for global events

    Precambrian Res.

    (2003)
  • G.M. Ross et al.

    Isotopic provenance of the lower Muskwa assemblage (Mesoproterozoic, Rocky Mountains, British Columbia): new clues to correlation and source areas

    Precambrian Res.

    (2001)
  • G.M. Ross et al.

    Provenance and U-Pb geochronology of the Mesoproterozoic Belt Supergroup (northwestern United States): implications for age of deposition and pre-Panthalassa plate reconstructions

    Earth Planet. Sci. Lett.

    (1992)
  • V.N. Sergeev et al.

    Paleobiology of the Mesoproterozoic-Neoproterozoic transition: the Sukhaya Tunguska Formation, Turukhansk Uplift, Siberia

    Precambrian Res.

    (1997)
  • M. Sharma et al.

    Genesis of carbonate precipitate patterns and associated microfossils in Mesoproterozoic formations of India and Russia – a comparative study

    Precambrian Res.

    (2004)
  • A.G. Sherman et al.

    Anatomy of a cyclically packaged Mesoproterozoic carbonate ramp in northern Canada

    Sed. Geol.

    (2001)
  • D. Thomson et al.

    Architecture of a Neoproterozoic intracratonic carbonate ramp succession: Wynniatt Formation, Amundsen Basin, Arctic Canada

    Sed. Geol.

    (2014)
  • D.J. Thorkelson et al.

    Early Mesoproterozoic intrusive breccias in Yukon, Canada: the role of hydrothermal systems in reconstructions of North America and Australia

    Precambrian Res.

    (2001)
  • P.I. Abell et al.

    Stratigraphic variations in carbon and oxygen isotopes in the dolostone of the Carswell Formation (Proterozoic) of northern Saskatchewan

    Can. J. Earth Sci.

    (1989)
  • G. Abbott

    Geology of NTS map area 116 A/10, eastern Ogilvie Mountains, Yukon Territory

    (1997)
  • G. Abbott

    Geology of the upper Hart River area, eastern Ogilvie Mountains, Yukon Territory (116A/10,116 A/11)

    (1997)
  • J.D. Aitken et al.

    Middle Proterozoic assemblages

  • P.A. Allen et al.

    Classification of Basins, with Special Reference to Proterozoic Examples

    (2015)
  • J.A. Barth et al.

    Cool water geyser travertine: Crystal Geyser, Utah, USA

    Sedimentology

    (2014)
  • J.K. Bartley et al.

    Deep-water microbialites of the Mesoproterozoic Dismal Lakes Group: microbial growth, lithification, and implications for coniform stromatolites

    Geobiology

    (2014)
  • M.A. Beeunas et al.

    Preserved stable isotopic signature of subaerial diagenesis in the 1.2-b.y. Mescal Limestone, central Arizona: Implications for the timing and development of a terrestrial plant cover

    Bull. Geol. Soc. Am.

    (1985)
  • J. Betrand-Sarfati et al.

    Stromatolites of the Mescal Limestone (Apache Group, middle Proterozoic, central Arizona): taxonomy, biostratigraphy, and paleoenvironments

    Geol. Soc. Am. Bull.

    (1992)
  • S.L. Blusson

    Geology of Bonnet Plume Pass, Goz Creek, Corn Creek, and Fairchild Lake map areas, Yukon Territory

    Geol. Surv. Can.

    (1974)
  • F. Böhm et al.

    Deep-water stromatolites and Frutexites Maslov from the early and Middle Jurassic of S-Germany and Austria

    Facies

    (1993)
  • J.A. Breyer et al.

    Possible new evidence for the origin of metazoans prior to 1 Ga: sediment-filled tubes from the Mesoproterozoic Allamoore Formation, Trans-Pecos, Texas

    Geology

    (1995)
  • M. Colpron et al.

    U-Pb zircon age constraint for late Neoproterozoic rifting and initiation of the lower Paleozoic passive margin of western Laurentia

    Can. J. Earth Sci.

    (2002)
  • M. Coniglio et al.

    Carbonate slopes

  • P.R. Dawes

    The Proterozoic Thule Supergroup, Greenland and Canada: history, lithostratigraphy and development

    Geol. Greenland Surv. Bull.

    (1997)
  • G. Delaney

    The Middle Proterozoic Wernecke Supergroup, Wernecke Mountains, Yukon Territory

    (1985)
  • Cited by (16)

    • Spatial distribution of 1.4-1.3 Ga LIPs and carbonatite-related REE deposits: Evidence for large-scale continental rifting in the Columbia (Nuna) supercontinent

      2022, Earth and Planetary Science Letters
      Citation Excerpt :

      Previous geological and geochemical results for the 1.4-1.3 Ga LIPs in different cratons within Columbia supercontinent show that most of them represent intraplate magmatism related to continental rifting or rifting to drifting resulted in breakup of Columbia (Doughty and Chamberlain, 1996; Tack et al., 2010; Zhang et al., 2017a; Ernst et al., 2013; Puchkov et al., 2013; Mäkitie et al., 2014; Teixeira et al., 2015; Medig et al., 2016; Verbaas et al., 2018). For example, the Hart River mafic sills recorded an episode of continental rifting of western Laurentia at 1.38 Ga (Verbaas et al., 2018), which is consistent with rifting to drifting environment and the separation of Laurentia from Australia as inferred from sedimentary sequences of the Mesoproterozoic Pinguicula Group of northern Yukon (Medig et al., 2016) and geochemical evidence from the Belt-Purcell Supergroup of the northwestern US and adjacent Canada (Luepke and Lyons, 2001). The ca. 1380 Ma Mashak (Kama-Belsk) igneous province in Baltica was considered to be related to a continental rifting event between eastern Baltica and eastern Siberia (Puchkov et al., 2013).

    • A Mesoproterozoic carbonate platform (lower Belt Supergroup of western North America): Sediments, facies, tides, tsunamis and earthquakes in a tectonically active intracratonic basin

      2021, Earth-Science Reviews
      Citation Excerpt :

      Unlike some Archean and Proterozoic platforms (e.g., Sumner, 1997; Grotzinger and James, 2000; Bekker and Eriksson, 2003; Hood et al., 2011; Hood and Wallace, 2012), marine precipitates in the form of isopachous and spherulitic fibrous cements are absent in the lower Belt, although microcrystalline calcite cementation was widespread in the Waterton–Altyn succession. Micritic aggregates and small intraclasts are dominant allochems in the dolograinstones, but these kinds of particles seem to have been only rarely noted in other Precambrian carbonate platforms (Medig et al., 2016). Similar grains, however, are volumetrically important or dominant in some Cambro-Ordovician platforms (Pratt et al., 2012).

    • The Precambrian paleogeography of Laurentia

      2021, Ancient Supercontinents and the Paleogeography of Earth
    • Cryogenian of Yukon

      2018, Precambrian Research
      Citation Excerpt :

      Sequence A consists of ∼1.7–1.2 Ga poly-deformed carbonate and siliciclastic rocks of the Wernecke Supergroup (Delaney, 1981; Furlanetto et al., 2013). Sequence B consists of the ∼1.2–0.78 Ga Mackenzie Mountains Supergroup, which is broadly equivalent to the Pinguicula, Hematite Creek, and Fifteenmile groups in Yukon, although there may not be correlatives with the Pinguicula Group in the Northwest Territories (Medig et al., 2016). Sequence C consists of the ∼0.78–0.54 Ga Windermere Supergroup and various equivalents in Yukon described herein (Fig. 2).

    View all citing articles on Scopus
    View full text