Exploration of conventional/unconventional hydrocarbon resources relies on detailed analysis of source/reservoir rocks. Rock-Eval analysis is one of the major methods in screening and characterizing the organic matter type and quantity, thermal maturity, and hydrocarbon potential of sedimentary rocks (Lafargue et al., 1998). In addition, Rock-Eval analysis is also widely used for characterization of organic matter in recent sediments and soil in wide range of environmental and soil fertility studies (e.g., Sanei et al., 2005; Carrie et al., 2012). Fundamentals of Rock- Eval analysis are provided in detail in Lafargue et al. (1998) and Behar et al. (2001). In order to determine the accuracy and precision of analysis, a formally certified standard reference material is typically analysed concurrently with samples to assure the consistency of measured data. However, no commercially available certified reference materials have been characterized for the parameters measured during Rock-Eval analysis. Instead, the Geological Survey of Canada (GSC) Organic Geochemistry Laboratory uses an internal prepared standard (9107) that was calibrated against a rock standard provided by the instrument manufacturer. That standard was developed by using various gravimetric approaches and external calibration of the Rock-Eval flame ionization (hydrocarbons) and thermal conductivity or infrared (CO and CO2) detectors. The 9107 standard is from the Upper Cretaceous Second White Speckled Shale, Colorado Group in western Canada, which is regarded as a typical marine hydrocarbon source rock. This standard is run in a sample batch of 10 to 15 unknown samples to verify the analytical performance of Rock-Eval instrument and ensure the consistency of generated data throughout series of analyses. This report presents the summary results of more than 2000 runs of the 9107 standard since the deployment of three completely refurbished Rock-Eval 6 instruments at the GSC in 2007documenting the accepted values of selected measured Rock-Eval 6 parameters and measurement precision and margin of error for the 9107 standard.

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.

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<p>The Devonian has long been a problematic era for paleomagnetism. Devonian data are generally difficult to interpret and have complex partial or full overprints. These problems arise from paleomagnetic data obtained from both sedimentary and igneous rocks. As a result, the reconstruction of motions of tectonic plates is often troubling, as these rely on apparent polar wander paths constructed from Devonian paleomagnetic poles. Also the geomagnetic polarity time scale for this time period is poorly constrained. Paleointensity studies suggest that the field was much weaker than the field of today, and it has been hypothesised that this was accompanied by many polarity reversals (a hyperreversing field). We review studies on Devonian paleopoles, magnetostratigraphy and paleointensity. We tentatively suggest that the field during the Devonian might have been so weak and perhaps of a non-dipolar configuration, that obtaining reliable paleomagnetic data from Devonian rocks is extremely difficult.  In order to push forward the understanding of the Devonian field, we emphasise the need for studies to provide fully accessible data down to specimen level demagnetisation diagrams. Incorporating all data, no matter how complex or bad they might seem, is the only way to advance the understanding of the Devonian magnetic field. Recent paleointensity studies appear to suggest that the Devonian and Ediacaran were both extreme weak field intervals. For the Ediacaran, it has been hypothesised that the field had an impact on life on earth. A fundamentally weak and perhaps non-dipolar field during the Devonian might have had an influence on evolution and extinctions. As there is a large number of biological crises in the Devonian, we here pose the question whether the Earth’s magnetic field was a contributing factor to these crises. New independent evidence from the Devonian-Carboniferous boundary suggests that the Hangenberg event was caused by increased UV-B radiation, which is in line with a weak magnetic field.</p>

<p>The global polarity time scale (GPTS) is relatively unconstrained for the Paleozoic, particularly the Devonian. Constraining the GPTS and reversal frequency for the Devonian is crucial for the understanding of the behaviour of Earth’s magnetic field. Furthermore, construction of a GPTS for the Paleozoic could provide a valuable tool for age determination in other studies. However, most paleomagnetic data from the Devonian is problematic. The data are difficult to interpret and don’t have a single easy to resolve (partial or full) overprint. Paleointensity studies suggest that the field was much weaker than the field of today, which could have been accompanied by many reversals (a hyperreversing field). In order to improve the geomagnetic polarity time scale in the Devonian, and quantify the number of reversals in this time, we sampled three Devonian sections in Germany, Poland and Canada. These sections show evidence that the rocks were not significantly heated, and they show little evidence for remineralisation. This minimises the chance the rocks were remagnetised after the Devonian. Our data show that even when rocks are well qualified to have reliably recorded the Devonian field, the interpretation is not straightforward. We also discuss problems with the Devonian GPTS as presented in the geologic timescale.</p>

The Devonian, like much of the Paleozoic, has long been a problematic period for paleomagnetism. Devonian paleomagnetic data are generally difficult to interpret and have complex partial or full overprints; problems that arise in data obtained from both sedimentary and igneous rocks. As a result, the reconstruction of tectonic plate motions, performed largely using apparent polar wander paths, has large uncertainty. Similarly, the Devonian geomagnetic polarity time scale is very poorly constrained. Paleointensity studies suggest that the field was much weaker than the modern field, and it has been hypothesised that this was accompanied by many polarity reversals (a hyperreversing field). We sampled middle to upper Devonian sections in Germany, Poland and Canada which show low conodont alteration indices, implying low thermal maturity. We show in this study that there are significant issues with these data, and they are not straightforward to interpret, even though no significant heating and remineralisation was likely to have caused overprinting. We compare our data to other magnetostratigraphic studies from the Devonian and review the polarity pattern as presented in the Geologic Time Scale. Combined with estimates for the strength of the magnetic field during the Devonian, we suggest that the field during the Devonian might have been so weak and in part non-dipolar that obtaining reliable primary paleomagnetic data from Devonian rocks is challenging. Careful examination of all data, no matter how unusual, is the best way to push forward our understanding of the Devonian magnetic field. Paleointensity studies show that the field during the Devonian had a similar low strength to that recently advocated during the Ediacaran. Independent evidence from malformed spores around the Devonian-Carboniferous boundary suggests that the terrestrial extinction connected to the Hangenberg event, was caused by increased UV-B radiation, supporting the weak field hypothesis. A fundamentally weak and possibly non-dipolar field during the Devonian could have been produced, in part, by true polar wander acting to maximise core-mantle heat flow in the equatorial region. It may also have influenced evolution and extinctions in this time period. There is a large-number of paleobiological crises in the Devonian, and we pose the question, did the Earth's magnetic field influence these crises?

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