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Conodont biostratigraphic research on the Comabella Formation at Villech (Spanish Central Pyrenees), a 54 m thick pinkish-greyish compact hemipelagic limestone section situated in the Compte "subfacies area", reveals an Eifelian to early Frasnian age for the studied interval. The base of the Formation is of lower Eifelian age (costatus Zone), indicated by the lowest local record of Polygnathus angustipennatus, associated with P. partitus. The kockelianus and eiflius zones are recognized in the lower half of the section. The uppermost Eifelian and lowermost Givetian (ensensis and hemiansatus zones, respectively) have not been found so far but might be located in a covered interval. Other biozones recognized in the section are the timorensis-rhenanus/varcus, ansatus, semialternans, hermanni, disparilis and norrisi zones in the Givetian, all indicated by their respective index species and the MN1 Zone (occurrence of Ad. binodosa and Ad. pristina) in the Frasnian. A black shale and limestone layer in the upper part of the Villech section could represent the local signature of the upper part of the global Taghanic Crisis.•

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Hyper-enriched black shale (HEBS) Ni-Mo-Zn-Pt-Pd-Au-Re mineralization is geographically widespread across the Richardson trough in northern Yukon (Canada), where it discontinuously outcrops at the regional contact between the Road River Group and overlying Canol Formation. Stratigraphic relationships indicate that the contact is Middle Devonian, but there are no precise age constraints for the HEBS. We apply Re-Os geochronology to HEBS mineralization from two localities that are 130 km apart, the Nick prospect and the Peel River showing, to date directly the age of sulfide mineralization. The Nick prospect yields an isochron age of 390.7 ± 5.1 (2σ) Ma, whereas the Peel River showing yields an isochron age of 387.5 ± 4.4 (2σ) Ma. Within error, these ages are identical and overlap with the biostratigraphically constrained age of the sedimentary host rocks, indicating that mineralization and sedimentation were coeval. Significantly, the ages of the HEBS overlap those of Middle Devonian Kačák, pumilio, and Taghanic global-scale biotic events which are characterized by eustatic sea-level rise and black shale deposition. Linkage of the Yukon HEBS to one (or more) of these bio-events indicates that sea-level rise may have been requisite to formation of basin-scale HEBS mineralization in northwestern Canada during latest Eifelian and Givetian time.

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This study proposes six new lithostratigraphic units and redefines two others within the Horn River Group (HRG), a shale-dominated succession recently prospected for shale hydrocarbons. Its lower Hare Indian Formation rests on a drowning unconformity. In the SOB area (the area between Norman Wells and the Keele tectonic zone), this formation consists of the Bluefish black shale, Francis Creek grey shale, and Prohibition Creek black shale members. The latter two are lateral equivalents of the grey shale Bell Creek Member (updated definition) in the northern part of the study area. The overlying Canol Formation in the SOB area is divided into the Vermillion Creek and Dodo Canyon members. The Prohibition – Dodo Canyon package is ≥100 m thick and composed of brittle siliceous mudrocks with median SiO2 68%–79%, Al2O3 6%–9%, varying amount of calcite and dolomite, and type I–II kerogen with median TOC 4.5%. The thin Canol Formation blanketing Kee Scarp carbonate banks is identified as its Dodo Canyon Member. The latter is a “sweet bed” for fracking with median SiO2 75%–79%, TOC 5.1%, and trace-metal signatures indicating strongest anoxia in the section. The Mirror Lake Member in the base of the overlying Imperial Formation consists of soft illite-rich grey shales with minor siderite and dolomite. The overlying Loon Creek Member is composed of Canol-like black shale facies in its basal part and less organic-rich, lighter-colored shales and siltstones above. The Loon Creek Member is partly coeval with an overlying succession of sandstones and siltstones of the Canyon Member in its updated definition. Conodont data do not indicate significant time gaps between lithostratigraphic units. The majority of standard conodont zones from the uppermost Eifelian (ensensis Zone) up to the middle Frasnian (punctata Zone) are recognized. Assemblages of the hemiansatus and semialternans/latifossatus zones are missing probably owing to scarcity of conodont samples. The base of the HRG approximates the Eifelian–Givetian boundary, and the Hare Indian Formation is mostly Givetian. The Vermillion Creek Member spans the Givetian–Frasnian boundary. In places where thick Kee Scarp carbonates aggrade on thick sections of the Bell Creek Member, the Kee Scarp – Canol contact is found within the transitans Zone and the Middle Frasnian punctata Zone conodont assemblage is found in the basal part of the Dodo Canyon Member. The main part of the Dodo Canyon Member and basal beds of the Imperial Formation remain undated.

The 2019 field work on Prohibition Creek (SE of Norman Wells), a joint effort of GSC-Calgary and the DEEP research group of the University of Liverpool (UK), aimed to remeasure and sample the Eifelian-Frasnian succession of the Hume Formation and the Horn River Group. The latter is well exposed along Prohibition Creek and recommended as a reference section for the 'Canol shale play' in the adjacent Mackenzie Valley as rocks in studied outcrops occur in the zone of relatively low thermal maturity with high possibility of good preservation of primary paleo-magnetic, organic-matter, and geochemical signals. This report delivers illustrated baseline descriptions, gamma spectrometry logs, and correlation of measured sections (=field stations), and gives startup information on the field sampling based research. Match of sections from 2019 with sections measured in 2015 identifies a few miscorrelations in earlier versions, leading to improved gamma spectrometry empowered correlation with the subsurface.