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Document généré le 29 sept. 2021 11:15 Atlantic Geology Journal of the Atlantic Geoscience Society Revue de la Société Géoscientifique de l'Atlantique GAC - Newfoundland and Labrador Section Abstracts: 2019 Spring Technical Meeting Volume 55, 2019 URI : https://id.erudit.org/iderudit/1060421ar DOI : https://doi.org/10.4138/atlgeol.2019.007 Aller au sommaire du numéro Éditeur(s) Atlantic Geoscience Society ISSN 0843-5561 (imprimé) 1718-7885 (numérique) Découvrir la revue Citer ce document (2019). GAC - Newfoundland and Labrador Section Abstracts: 2019 Spring Technical Meeting. Atlantic Geology, 55, 243–250. https://doi.org/10.4138/atlgeol.2019.007 All Rights Reserved ©, 2019 Atlantic Geology Ce document est protégé par la loi sur le droit d’auteur. L’utilisation des services d’Érudit (y compris la reproduction) est assujettie à sa politique d’utilisation que vous pouvez consulter en ligne. https://apropos.erudit.org/fr/usagers/politique-dutilisation/ Cet article est diffusé et préservé par Érudit. Érudit est un consortium interuniversitaire sans but lucratif composé de l’Université de Montréal, l’Université Laval et l’Université du Québec à Montréal. Il a pour mission la promotion et la valorisation de la recherche. https://www.erudit.org/fr/ Geological Association of Canada, Newfoundland and Labrador Section ABSA TR CTS 2019 Spring Technical Meeting St. John’s, Newfoundland and Labrador The annual Spring Technical Meeting was held on February 18 and 19, 2019, in the Johnson GEO CENTRE on scenic Signal Hill in St. John’s, Newfoundland and Labrador. The meeting kicked-off Monday evening with a Public Lecture entitled “Meteors, Meteorites and Meteorwrongs of NL” by Garry Dymond from the Royal Astronomical Society of Canada. Tuesday featured oral presentations from students and professionals on a wide range of geoscience topics. As always, this meeting was brought to participants by volunteer efforts and would not have been possible without the time and energy of the executive and other members of the section. We are also indebted to our partners in this venture, particularly the Alexander Murray Geology Club, the Johnson GEO CENTRE, Geological Association of Canada, Department of Earth Sciences (Memorial University of Newfoundland), and the Geological Survey of Newfoundland and Labrador, Department of Natural Resources. We are equally pleased to see the abstracts published in Atlantic Geology. Our thanks are extended to all of the speakers and the editorial staff of the journal. JAMES CONLIFFE AND ALEXANDER PEACE TECHNICAL PROGRAM CHAIRS GAC NEWFOUNDLAND AND LABRADOR SECTION ATL ANTIC GEOLOGY 55, 243 - 250 (2019) doi: 10.4138/atlgeol.2019.007 Copyright © Atlantic Geology 2019 0843-5561|19|00243-250 $2.20|0 ATLANTIC GEOLOGY · VOLUME 55 · 2019 244 process results in the production of highly reducing, Automatic microearthquake locating using characteristic ultra-basic fluids that cause a characteristic travertine functions in a source scanning method deposit when these fluids emerge. The fluids at sites of serpentinization are rich in methane and hydrogen gas. The Hilary Chang1, Alison Malcolm1, Frédérick Massin2, methane can be produced biotically or abiotically; therefore, and Francesco Grigoli2 its detection alone is insufficient evidence to indicate the presence of life. Affinity calculations were performed to 1. Department of Earth Sciences, Memorial identify other likely biochemical reactions that could be University of Newfoundland, St. John’s, Newfoundland occurring at these sites to identify alternative products and Labrador A1B 3X5, Canada ¶ indicative of present life at active sites of serpentinization. 2. ETH Zurich, Department of Earth Sciences, Zürich, Switzerland The results from these predictive calculations indicated the Microearthquake locating has broad application oxidation of methane should be favoured at the Tablelands. in monitoring volcanic activities or human-induced This hypothesis was tested through a series of laboratory earthquakes. However, typically large amounts of data experiments using sediment and fluids containing native are involved and those data are quite noisy. Hence, an microbial communities from a spring at the Tablelands. automatic procedure is needed that can accurately locate A microbial observatory was also created in 2017 by these microearthquake events. In this research, we tackle drilling three holes and inserting incubators into the this problem by stacking Characteristic Functions (CFs) subsurface. These incubators were left for a year to collect in the Source Scanning Algorithm (SSA). The CFs allow microbial communities that are representative of life in us to consider waveform characteristics such as amplitude the subsurface. Extractions will be performed on these and polarization in the locating problem; and the SSA incubators to identify lipids that can be used to indicate allows us to search the solution space automatically with the presence of life at these springs. Experiments will minimum computing effort. Furthermore, we use multi- also be performed to better understand how these lipids scaled CFs to accommodate earthquake signals within degrade over time and how they are preserved. Together, a wide frequency band. We successfully locate synthetic these techniques will help identify biosignatures that could events generated at 6km using the SIL Network in Reykjane indicate present and past life at sites of serpentinization. Peninsula, SW Iceland. The SIL Network has a geometry of around 60 x 30 km. We also locate 215 events recorded by the same network with very similar results (less than 5% A paleomagnetic study of ca. 580 Ma volcanic rocks near outliers with 80% of the result within an error of 2.5 km, Grand Bank, Avalon Zone of Newfoundland, Canada, 0.1s) to the manual picking method. In conclusion, stacking and implications for true polar wander in the Ediacaran CFs in SSA is a noise-robust automatic method to locate microearthquakes in a reginal scale. It also avoids the need of manual phase picking and reduces human intervention. Sarah Farrell and Joseph Hodych Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador Identifying past and present life at a terrestrial site of A1B 3X5, Canada serpentinization: the Tablelands, western Newfoundland, Paleomagnetic studies suggest that Laurentia moved Canada from the equator to the pole and then back again within ~60 Ma during the Ediacaran. Since plate tectonic speeds Melissa C. Cook and Penny L. Morrill are not fast enough to allow this to happen, it has been hypothesized that inertial interchange true polar wander Department of Earth Sciences, Memorial University of occurred, causing the Earth to tumble through 90° and then Newfoundland, St. John’s, Newfoundland and Labrador back again. To help test this hypothesis, this study provides A1B 3X5, Canada new paleomagnetic data for ca. 580 Ma volcanic rocks of the Marystown Group collected near Grand Bank in the Avalon Serpentinization, the hydration of ultramafic minerals, is zone of Newfoundland. The volcanic rocks were studied with hypothesized to occur on Mars as well as other planetary alternating field and thermal demagnetization which showed bodies including Jupiter’s moon Europa, and Saturn’s that remanence is carried mostly by magnetite rather than moons Titan and Enceladus. Serpentinization also occurs hematite. Seven sites provide stable remanence directions in terrestrial settings in ophiolites that can be considered with mean tilt-corrected declination and inclination of analogues for these less accessible sites. The Tablelands is 287° and 58° (α95 = 13°). The corresponding paleolatitude an example of a terrestrial analogue. The serpentinization is 39° -12/+16. A positive conglomerate test, using rhyolitic Atlantic Geoscience Society 2019 - ABSTRACTS Copyright © Atlantic Geology 2019 ATLANTIC GEOLOGY · VOLUME 55 · 2019 245 crystal-lithic tuff clasts from an agglomerate, shows that distribution and control of crustal blocks on the evolution the magnetite-bearing clasts carry primary remanence. of sedimentary basins. The preliminary results show an Magnetic polarity reversals are present within the section. increased understanding of crustal block fragmentation The Marystown Group results, along with other stable is important in understanding stress/strain partitioning, paleomagnetic data from Avalonia, suggest that Avalonia basin evolution, and tectonostratigraphy along deformable remained at mid- to low-latitudes during the mid-Ediacaran. continental margins, including Newfoundland and its conjugates. Geophysically constrained microplate fragmentation model and microplate-controlled evolution of Mesozoic Geologizing the East Coast Trail: Could it be a candidate basins – riftedN orth Atlantic borderlands, offshore for a “classic rock tour”? Newfoundland, Canada Andrew Kerr Brant D. Gaetz and J. Kim Welford Department of Earth Sciences, Memorial University of MAGRiT (Memorial Applied Geophysics and Rift Tectonics) Newfoundland, St. John’s, Newfoundland and Labrador Research Group, Department of Earth Sciences, Memorial A1B 3X5, Canada University of Newfoundland, St. John’s, Newfoundland and Labrador A1B 3X5, Canada In 2018, Geoscience Canada initiated a new series of thematic articles entitled Classic Rock Tours. The idea Borderlands of offshore Newfoundland comprise a is to combine technical and historical context for well- deformed collage of fault bound crustal blocks, assembled known and geologically informative
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