00000nam 2200000zi 4500 9.923046 CaOODSP 20251031142448 m o d f cr mn||||||||| 230523t20232023oncab ob f000 0 eng d 9780660488288 CaOODSP eng rda CaOODSP eng eng fre n-cn--- M183-2/8980E-PDF Bourdeau, J. E., author. Regional-scale lake-sediment sampling and analytical protocols with examples from the Geological Survey of Canada / J.E. Bourdeau and R.D. Dyer. [Ottawa] : Geological Survey of Canada, 2023. ©2023 1 online resource (41 pages) : illustrations (some colour), maps (some colour). text txt rdacontent computer c rdamedia online resource cr rdacarrier Open file, 2816-7155 ; 8980 Includes bibliographical references (pages 33-41). "Regional-scale lake sediment surveys have been successfully used since the 1970s as a means for reconnaissance geochemical exploration. Lake sediment sampling is typically performed in areas with a lack of streams and an overabundance of small-sized (≤5 km across) lakes. Lake sediments are known to have major, minor and trace element concentrations that reflect the local geology. Overall, surveys are planned and conducted following four distinct stages: 1) background research, 2) orientation survey, 3) regional survey, and 4) detailed survey. At the Geological Survey of Canada, samples are usually collected from a helicopter with floats. Sample density ranges from 1 sample per 6 to 13 km². Samples are collected from the centre of the lake using a gravity torpedo sampler which corresponds to a hollow-pipe, butterfly bottom-valved sampler attached by a rope to the helicopter. Collected sediment samples are then placed in labelled bags and left to air dry. Detailed field notes and additional samples (field duplicates), for the purpose of a quality assurance and quality control program, are also taken. Samples are then milled and sent to analytical laboratories for element determination. Commonly used analytical methods include: X-ray fluorescence (XRF), atomic absorption spectroscopy (AAS), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and -mass spectrometry (ICP-MS), instrumental neutron activation analysis (INAA), and/or determination of volatile compounds and organic carbon using Loss on Ignition (LOI). Analytical data is first evaluated for quality (contamination, accuracy and precision). Numerous options for the analysis of lake sediment data exist, ranging from simple basic element concentration maps and statistical graphical displays with summary statistics, to employing multivariate and machine learning methodologies. By adopting the set of guidelines and examples presented in this report, scientific researchers, exploration geologists, geochemists and citizen scientists will be able to directly compare lake sediment datasets from anywhere in Canada"--Abstract, page 3. Includes abstracts in English and French. Lake sediments Sampling Canada Methodology. Lake sediments Canada Analysis Methodology. Geochemical surveys Canada Methodology. Sédiments lacustres Échantillonnage Canada Méthodologie. Sédiments lacustres Canada Analyse Méthodologie. Levés géochimiques Canada Méthodologie. Geological Survey of Canada, issuing body. Open file (Geological Survey of Canada) 8980. (CaOODSP)9.506878 PDF 10.81 MB https://publications.gc.ca/collections/collection_2023/rncan-nrcan/m183-2/M183-2-8980-eng.pdf HTML N/A https://doi.org/10.4095/331911