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TitleChemostratigraphy in southern Ontario by pXRF spectrometry
DownloadDownload (whole publication)
AuthorKnight, R; Russell, H A J; Bajc, F
SourceRegional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house; by Russell, H A J; Ford, D; Priebe, E H; Geological Survey of Canada, Open File 8212, 2017 p. 23,
PublisherNatural Resources Canada
MeetingOntario Geological Survey and Geological Survey of Canada groundwater geoscience open house; Guelph; CA; March 1-2, 2017
Documentopen file
Mediaon-line; digital
RelatedThis publication is contained in Russell, H A J; Ford, D; Priebe, E H; (2017). Regional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house, Geological Survey of Canada, Open File 8212
File formatpdf
NTS30; 31C; 31D; 40; 41A; 41G; 41H/03; 41H/04; 41H/05; 41H/06; 41H/12; 41H/13
AreaSouthern Ontario
Lat/Long WENS -84.0000 -76.0000 46.0000 41.5000
Subjectshydrogeology; stratigraphy; geochemistry; groundwater; aquifers; glacial deposits; stratigraphic analyses; sediment geochemistry; in-field instrumentation; spectrometric analyses; x-ray fluorescence analyses; boreholes; core samples; sample preparation; mass spectrometer analysis; calcium; iron; potassium; manganese; rubidium; strontium; vanadium; zinc; zirconium; barium; copper; chromium; titanium; lead; quality control; Phanerozoic; Paleozoic; Devonian; Silurian; Ordovician; Cambrian
Natural Resources Canada Library - Ottawa (Earth Sciences)
ProgramAquifer Assessment & support to mapping, Groundwater Geoscience
Released2017 02 22
AbstractFor groundwater studies, the collection of sediment geochemistry is often beyond the scope, and budget of many programs, and is generally not included as part of routine data collection. Portable x-ray fluorescence spectrometer (pXRF) has proven to be a successful tool to characterize the chemostratigraphy of glacial derived materials collected from boreholes in southern Ontario. Portable XRF provides near-total geochemistry results similar to fusion and multi-acid methods for 14 elements with minimal sample preparation and at low cost. An extensive suite of near surface samples provides characterization of the regional geochemistry. In a collaborative project with the OGS and the GSC two transects are being completed (E-W, N-S) to provide a framework of subsurface geochemistry. To eliminate the effects of variability in sample grain-size, sample volume, and to minimize nugget effects, samples are dried and sieved to <0.063 mm (silt + clay) prior to analysis. To ensure quality control, a number of Standard Reference Materials (SRM) and Certified Reference Materials (CRM) are analyzed with each project, and comparisons made with previously published results. For further quality control, a sub-suite of sediment samples are analyzed by ICP-MS/ES using lithium borate fusion, multiacid, and aqua regia digestions.
Bivariate plots comparing pXRF to ICP-MS/ES display a high degree of linearity (r2 > 0.8) for Ca, Fe, K, Mn, Rb, Sr, V, Zn, Zr, and to a lesser degree for Ba, Cu, Cr, Ti, and Pb. These 14 elements return precise and generally accurate results within each borehole; however, continued analyses of CRM's and SRM's has demonstrated display drift in accuracy between projects. Resulting data for meet the US EPA criteria for quantitative data quality based on r2 values and y=mx+b relationships. Concentration levels play a significant factor in the accuracy of the pXRF data. At low concentration levels near the detection limit of the pXRF, there can be greater scatter in results. At high concentration levels, data needs to be adjusted using post-data calibration to obtain accurate results.