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Regional Lake Sediment Geochemistry Help File |
CONTENTS:
IntroductionGeochemical Survey Design
History
Sampling Methods
Sample Preparation
Analytical Methods for Sediments
Analytical Methods for Waters
Quality Control
Images and Contours
Geochemical Surface Interpolation Procedure
Line Contour Procedure
Tables
Table 1: Variables in regional lake sediment database.
Table 2: Codes for Analysis Techniques
Analysis Techniques
Atomic Absorption Methods
Colorimetric Analysis
Gravimetric Analysis
Potentiometric Analysis
Neutron Activation, Delayed Neutron Counting Analysis
Instrumental Neutron Activation Analysis
Acknowledgements
Disclaimer
Recommended Citation
Reference
Contact
INTRODUCTION
This help file contains documentation for the geochemical data for lake
sediment and water for the digital compilation of geoscience data for
Newfoundland and Labrador (south of latitude 58° 30´ N). The data are from
the National Geochemical Reconnaissance (NGR) Survey reports (see References). The
geochemical data can be displayed in several formats (or coverages),
including a comprehensive database of field observations and geochemical
analyses (Table 1) for each site, the geochemical data
values provided as ranged dot plots, as well as interpolated geochemical
surfaces as both colour raster images and as line contours. The colour
raster format is the lowest resolution and is intended for broad overviews
of large areas, when the individual pixels representing 1000 by 1000 m grid
cells are not apparent. The line contours, derived from the same
interpolated surface, through their labels provide quantitative estimates of
element concentrations in contrast to the raster surface which provides only
relative levels. The line contours are more effective at larger scales, but
plotting the individual site values provides the most detailed level of
information. Whereas the raster images are prepared using specialized
software and can only be turned on or off, the viewing software itself can
be used to illustrate variations in element concentrations from site to site
by, for example, using incrementally sized symbols.
In 2011, the sediments from the original NGR study were reanalyzed using a Fisons Instruments Maxim
III fully simultaneous Inductively Coupled Plasma-Emission Spectrometer
(ICP-ES) and Thermo Instruments Iris High Resolution ICP-ES. Thirty
elements were analysed using the method described in the 2012 open file report
Lab/1602.
This link also provides a further link to the downloadable database, in .csv format,
containing the old data as well as the new ICP data, identified by suffix of
'2' (e.g., Cu2_ppm).
GEOCHEMICAL SURVEY DESIGN
HISTORY
Geochemical mapping of Labrador (south of latitude 58° 30´ N) using organic lake-sediment is complete for 34 elements, viz. Ag, As, Au, Ba, Br, Ce, Co, Cr, Cs, Cu, Eu, F, Fe, Hf, Hg, La, Lu, Mn, Mo, Na, Ni, Pb, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, V, W, Yb and Zn, plus loss on ignition (LOI), with partial coverage for Cd and V as well. In addition, F, U and pH were measured in lake water. These sample media were employed because of the abundance of lakes throughout most of Labrador, and their effectiveness for geochemical mapping (Hornbrook et al., 1975). Collection of samples from over 18 000 sites was carried out using float-equipped helicopters between 1977 and 1985 by contractors for the Geological Survey of Canada under the National Geochemical Reconnaissance program - NGR - (Friske and Hornbrook, 1991). The data were first released as a series of open files (see References).
SAMPLING METHODS
Grab samples of organic-rich sediment from the central basins of lakes were obtained with a tubular steel corer that was allowed to free-fall from the water surface. A sediment core 10 to 20 cm long was typically obtained from a depth of about 20 to 120 cm below the sediment-water boundary (the depth depending on the penetrability of the sediment and the water depth at the sample site). After discarding the top few centimetres, the remaining material was placed in a pre-numbered, kraft-paper sample bag.
SAMPLE PREPARATION
Field dried sediment samples were air-dried in Ottawa, crushed and ball-milled. The minus 80 mesh (<0.177 mm) fraction was obtained and used for the initial geochemical analysis. During sample preparation, control reference and blind duplicate samples were inserted into each block of 20 samples for internal quality control. For reanalysis by INAA, archived un-milled material was pulverized using a ceramic swing mill. Water samples were collected in clean 250 mL polyethylene bottles. Only control reference samples were used for quality control.
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ANALYTICAL METHODS: SEDIMENTS
Samples were analysed by several techniques, some elements by two methods. To allow ready distinction between the different analytical methods, when data for an element are referred to, a numerical code is associated with the standard element abbreviation (i.e. Co1, Co3, etc). These codes are explained below. The nominal detection limits for each element by each method are given in Table 3 together with their medians and ranges in the total sample set.
Atomic Absorption Methods (AAS)
Colorimetric Methods (CA)
Gravimetric Analysis (GA)
Potentiometric Analysis (PA)
Neutron Activation, Delayed Neutron Counting (DNA)
Instrumental Neutron Activation Analysis (INAA)
ANALYTICAL METHODS: WATERS
Uranium, fluoride and pH were determined in lake water. Fluoride (Fw9) and pH (pHw) were determined by specific ion and a Beckman glass-calomel combination electrodes, respectively. Fluoride was measured using an Orion fluoride electrode and meter, following the addition of a total ionic strength buffer solution. After these two determinations were completed, the remaining water in the sample bottle (about 225 ml) was acidified with 3 ml of concentrated HNO3. At least two weeks after acidification, uranium analysis was carried out.
Uranium in water was determined by two methods. On samples collected after 1980 a laser-induced fluorometric method using a Scintrex UA-3 analyser was used (Uw10). A complexing agent known commercially as Fluran, composed of sodium pyrophosphate and sodium monophosphate, was used to produce the uranyl pyrophosphate species that fluoresces when exposed to a pulsed nitrogen laser (Hall, 1979). Organic matter may fluoresce, so a known addition method was employed to eliminate the effects of variable organic content. Samples collected before 1980 were analysed by fission track analysis (Uw11), in which 5 µl aliquots were placed on a polycarbonate tape, together with calibration standards, and dried. The tape was then irradiated in a nuclear reactor for 1 h in a flux of 10**13 neutrons/cm2/s. Subsequently the tape was etched with 25% NaOH solution and the fission tracks counted with an optical counter fitted to a microscope. The number of tracks was proportional to uranium concentration.
Some level problems have been noticed in the pH and U data between the older (pre-1980) and younger (post 1980) samples. For this reason, no interpolated surfaces have been created for them, although the results are included on the site data file. No levelling problems were encountered for Fw9.
QUALITY CONTROL.
Data quality was monitored through the collection of site-duplicate samples at a frequency of 5% of the lakes sampled, the splitting of 1 sample in 20 during sample preparation to give laboratory duplicates, and the inclusion of bulk controls (both internal and national reference materials) also at a frequency of 5% throughout the analytical program. The controls measure the consistency of the calibration thoughout the extended period of analysis (1977 to 1994) and, from national reference materials, the accuracy of reported element levels. From the laboratory and site duplicates the analytical variance, and the combined sampling and analytical variance, respectively, have been estimated using the procedure of Garrett (1973). It is the relative size of the combined sampling and analytical errors with respect to the overall data variance that is important in assessing data quality. Table 3 presents the proportions of these combined errors as a percentage of total data variance for each element (and by each analytical method where more than one was employed). The proportion of combined errors should not exceed 20 to 25 % for geochemical features to be well defined (Ramsey et al., 1992; Garrett, 1969). Some elements whose quality is rated as "poor" in Table 3 are those where the analytical detection limit is close to or above the median level for the whole data set. In regions where these elements are locally above the overall background, however, their reproducibility is much better and their spatial distribution is adequately defined.
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IMAGES AND CONTOURS
Geochemical Surface Interpolation Procedure
An interpolated surface was created for each element in four steps as follows:
1) individual values (log-transformed, except for Hf1 and LOI) were interpolated to an initial 4 by 4 km grid from the irregularly distributed sample sites using an iterative, minimum-curvature, surface-fitting technique (Geosoft, 1991),
2) a 3 by 3 cell (12 by 12 km) moving adapted trimmed mean (ATM) filter was then applied to smooth the grid and remove extreme values (Chork and Mazzucchelli, 1989; Davenport et al., 1991),
3) the ATM grid was smoothed further by applying a "Hanning" filter (a 3 by 3 cell weighted moving average filter),
4) the smoothed 4 by 4 km grid was interpolated to a 2 by 2 km grid, and then to a 1 by 1 km grid for final plotting using the Geosoft (1991) routine "BIGRID".
The frequency distribution of several elements are significantly truncated by the analytical detection limit. Values less than detection were arbitrarily assigned a value of half of the detection limit prior to interpolation. For ATM windows containing cells with these assigned values, the resulting "means" can no longer be considered rational measures of concentration. The deviation from a rational scale of measurement increases as the proportion of assigned values to measured values in the filter window increases, but the computed "means" will maintain at least an ordinal relationship. The images, especially at lower concentration levels, show only relative or semi-quantitative variations.
Line Contour Procedure
A third method of visualization of the geochemical surfaces is as vector line contours or isopleths at specific concentration levels. These were created only for those elements whose quality was rated "fair" or better (i.e. those whose noise, based on field duplicates, was <= 30% of their overall signal). The contours were based on the surface interpolation images (see above). Up to 21 contours at the 98th, 95th, 90th, 85th, 80th, 75th, 70th, 65th, 60th, 55th, 50th, 45th, 40th, 35th, 30th, 25th, 20th, 15th, 10th and 5th percentiles were drawn. The actual number of contours for each element depends on the degree of truncation of the data by the analytical detection limit; no contours are drawn below an element's detection limit. The vector contours can be downloaded from the Geoscience Atlas Download Tool - the contours are listed in the bottom half of the Layer list, below Geophysics.
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| VARIABLE | DESCRIPTION |
| Record | Identification number |
| Sample_ID | ID number unique to 1:250,000 NTS sheet |
| NTS | NTS map sheet (1:250,000 for Labrador, 1:50 000 for Newfoundland) |
| Ag3_ppm | Silver, ppm, by FAAS (Aqua Regia digestion) |
| Ag6_ppm | Silver, ppm, by FAAS (HNO3 digestion) |
| As1_ppm | Arsenic, ppm,by INAA |
| As19_ppm | Arsenic, ppm, by HAAS |
| As21_ppm | Arsenic, ppm, by COL |
| Au1_ppb | Gold, ppb, by INAA |
| Ba1_ppm | Barium, ppm, by INAA |
| Br1_ppm | Bromine, ppm, by INAA |
| Cd3_ppm | Cadmium, ppm, by FAAS |
| Ce1_ppm | Cerium, ppm, by INAA |
| Co1_ppm | Cobalt, ppm, by INAA |
| Co3_ppm | Cobalt, ppm, by FAAS |
| Cr1_ppm | Chromium, ppm, by INAA |
| Cs1_ppm | Cesium, ppm, by INAA |
| Cu3_ppm | Copper, ppm, by FAAS |
| Eu1_ppm | Europium, ppm, by INAA |
| F9_ppm | Fluorine, ppm, by PA |
| Fe1_pct | Iron, %, by INAA |
| Fe3_pct | Iron, %, by FAAS |
| Fw9_ppb | Fluorine in lake water, ppb, by PA |
| Hf1_ppm | Hafnium, ppm, by INAA |
| Hg18_ppb | Mercury, ppb, by CVAAS |
| La1_ppm | Lanthanum, ppm, by INAA |
| Lu1_ppm | Lutetium, ppm, by INAA |
| Mn3_ppm | Manganese, ppm, by FAAS |
| Mo1_ppm | Molybdenum, ppm, by INAA |
| Mo5_ppm | Molybdenum, ppm, by FAAS |
| Na1_pct | Sodium, %, by INAA |
| Ni1_ppm | Nickel, ppm, by INAA |
| Ni3_ppm | Nickel, ppm, by FAAS |
| Pb3_ppm | Lead, ppm, by FAAS |
| Rb1_ppm | Rubidium, ppm, by INAA |
| Sb1_ppm | Antimony, ppm, by INAA |
| Sc1_ppm | Scandium, ppm, by INAA |
| Se1_ppm | Selenium, ppm, by INAA |
| Sm1_ppm | Samarium, ppm, by INAA |
| Ta1_ppm | Tantalum, ppm, by INAA |
| Tb1_ppm | Terbium, ppm, by INAA |
| Th1_ppm | Thorium, ppm, by INAA |
| U1_ppb | Uranium, ppb, by INAA |
| U8_ppm | Uranium, ppm, by NANC |
| Uw10_ppb | Uranium in lake water, ppb, by LIF |
| Uw11_ppb | Uranium in lake water, ppb, by FTA |
| V5_ppm | Vanadium, ppm, by FAAS |
| W1_ppm | Tungsten, ppm, by INAA |
| Yb1_ppm | Ytterbium, ppm, by INAA |
| Zn1_ppm | Zinc, ppm, by INAA |
| Zn3_ppm | Zinc, ppm, by FAAS |
| LOI_pct | Loss-on-ignition, %, by GA |
| INAAWT_g | Sample weight (g) used for INAA |
| pHw | pH (hydrogen ion activity) in lake water, by PA |
| LakeArea_ha | Lake area, ha |
| LakeSize | range of lake size (e.g., 0.25 - 1 km2) |
| SampDpth_m | Lake depth, m, at sample site |
| Depth_m | Lake depth, m, at sample site |
| Year | Year of sample collection |
| Vegetation | Vegetation in the area (e.g. swamp, forest, barren) |
| Colour | Sediment colour |
| SampCompos | Sample composition (e.g. clastic vs. organic, ooze, peat) |
| Contaminat | Site contaminant (e.g. mining, road, settlement) |
| Contamin | Site contamination code; 0 - absent; 1 - present |
| UTMZone | UTM Zone |
| Utmeast | UTM easting, m, NAD27 |
| Utmnorth | UTM northing, m, NAD27 |
| Geology | Bedrock geology unit (1:1 million scale) |
| Surfical | Surficial geology unit |
| Openfile1 | Geological Survey of Canada Original open file number |
| Openfile2 | Geological Survey of Canada Latest open file number |
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| CODE | DESCRIPTION |
| AAS | Atomic absorption spectrophotometry |
| COL | Colorimetry |
| CVAAS | Cold-Vapour atomic absorption spectrophotometry |
| FAAS | Flame atomic absorption spectrophotometry |
| FTA | Fission track analysisGA Gravimetricanalysis |
| HAAS | Hydride atomic absorption spectrophotometry |
| INAA | Instrumental Neutron Activation Analysis |
| LIF | Laser induced fluorescence |
| NANC | Neutron Activation, delayed Neutron Counting |
| PA | Potentiometric analysis |
ANALYSIS TECHNIQUES
Atomic Absorption Spectroscopy (AAS)
Silver, cadmium, cobalt, copper, iron, manganese, nickel, lead and zinc (Ag3, Cd3, Co3, Cu3, Fe3, Mn3, Ni3, Pb3 and Zn3) were determined by atomic absorption spectroscopy using an air-acetylene flame. Sample aliquots of 1 g of sediment were digested in 6 ml of a 4M HNO3, 1M HCl mixture in test tubes, initially overnight at room temperature. The test tubes were then placed in a water bath and brought up to 90°C, and held at that temperature for 2 h with periodic shaking. The sample solutions were cooled, diluted to 20 ml with de-ionized water and mixed. For typical organic lake sediment this digestion yields values that are >80% of total content (Davenport et al., 1993). Arsenic (As19) was determined on the same sample solution using a hydride evolution method (Aslin, 1976), whereby As was evolved as AsH3 which was passed through a heated quartz tube mounted in the light path of an atomic absorption spectrophotometer. Molybdenum and vanadium (Mo5 and V5) were determined on 0.5 g aliquots of sample following digestion in 1.5 ml of concentrated HNO3 overnight at room temperature, and then in a water bath at 90°C for 30 min. Following this, 0.5 ml of concentrated HCl was added, and the sample s returned to the water bath for a further 90 min. After cooling, 8 ml of 1250 ppm Al solution was added, and the solution volume made up to 10 ml with de-ionized water before aspirating in a nitrous oxide - acetylene flame. For typical organic lake sediment this digestion yields Mo values that are close to its total content. Mercury (Hg18) was determined on 0.5g aliquots of sample following digestion in 20 ml of concentrated HNO3 and 1 ml of concentrated HCl in test tubes for 10 min at room temperature, and then in a water bath at 90°C for 2 h (Jonasson et al., 1973). After digestion the sample solutions were cooled and diluted to 100 ml with de-ionized water. The Hg present was reduced to the elemental state by the addition of 10 ml 10% w/v SnSO4 in 1M H2SO4. The Hg vapour was then flushed by a stream of air into an absorption cell mounted in the light path of an atomic absorption spectrophotometer.
Colorimetric Analysis (COL)
Arsenic (As21) was determined colorimetrically on some samples using silver diethyldithiocarbamate, following sample digestion of 1 g aliquots of sample in a 20 ml of 6M HCl at 90°C for 90 min. Colorimteric measurements were made at 520 nm.
Gravimetric Analysis (GA)
Organic carbon content was estimated from the weight loss on ignition (LOI) during a controlled combustion in which 0.5 g aliquots of sample in a 30 ml beaker were placed in a cold muffle furnace and gradually heated to 500°C in air over a 3 h period. The samples were held at 500°C for 4 h, and then allowed to cool in a desiccator prior to weighing.
Potentiometric Analysis. (PA)
Fluorine (F9) content (total) was determined by fluoride-ion selective electrode (Ficklin 1970). The sample (0.25g) was fused with 1g of a 2:1 mixture of a Na2CO3-KNO3 flux for 10 minutes in a nickel crucible, and the residue dissolved in 1% citric acid.
Neutron Activation, Delayed Neutron Counting Analysis (NANC)
Uranium (U8) content (total) was determined using a neutron activation method with delayed neutron counting (Boulanger et al., 1975). A 2 g aliquot of sample was irradiated for 10 s in an operating flux of 8 x 10**13 neutrons/cm2/s. Following irradiation, samples were transferred to a counting facility where, after a 10 s delay, each sample was counted for 10 s. Calibration was carried out twice a day or as required, and one standard was analysed after every 20 samples.
Instrumental neutron activation analysis (INAA)
Weighed and encapsulated samples (10 g nominal weight) are packaged for irradiation together with internal standards and reference materials. Samples and standards are irradiated together with neutron flux monitors, allowed to decay for 7 days, and their gamma-ray spectrum measured in a high resolution germanium detector for count times of typically 500 s. Total contents of the following elements were determined:arsenic, gold, barium, bromine, cerium, cobalt, chromium, cesium, europium, iron, hafnium, lanthanum, lutetium, molybdenum, sodium, nickel, rubidium, antimony, scandium, samarium, tantalum, terbium, thorium, uranium, tungsten and ytterbium. (As1, Au1, Ba1, Br1, Ce1, Co1, Cr1, Cs1, Eu1, Fe1, Hf1, La1, Lu1, Mo1, Na1, Ni1, Rb1, Sb1, Sc1, Sm1, Ta1, Tb1, Th1, U1, W1 and Yb1, respectively).
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ACKNOWLEDGEMENTS
E.H.W Hornbrook directed the original Lake sediment surveys, which were jointly planned under a series of Mineral Development agreements by E.H.W Hornbrook and P.H. Davenport. P.W.B Friske coordinated the program of sample reanalysis by INAA. Lake sediment Sampling was conducted under the supervision of E.H.W Hornbrook, Y.T. Maurice and N.G. Lund by Marshall Macklin Monaghan Ltd., Toronto (1977-1984), and MPH Consulting Ltd., Toronto (1985). Sample preparation was conducted under the supervision of J.J. Lynch initially by Golder Associates, Toronto, and for the INAA reanalysis program by Bondar Clegg Ltd., Ottawa.
GEOCHEMICAL ANALYSIS was carried out under the supervision of J.J. Lynch by Chemex Labs, Vancouver; Bondar Clegg Ltd., Ottawa; Barringer Research Ltd., Toronto; Acme Analytical Laboratories, Vancouver; Atomic Energy of Canada Ltd., Ottawa; and Becquerel Laboratories Ltd., Mississauga.
REPORT PREPARATION AND GENERAL SUPPORT was provided by C.C Durham, M.W. McCurdy, H. Gross, S.W. Adcock, A.C. Galletta, P. Doyle, S.J. Day and S. Carberry.
FUNDING was provided by the Governments of Newfoundland and Labrador and Canada through the following Mineral Development Agreements:
- Canada-Newfoundland Mineral Development Subsidiary Agreement, 1977-1981
- Canada-Newfoundland cooperative mineral program, 1982-1984
- Canada-Newfoundland Mineral Development Agreement, 1984-1989
- Canada-Newfoundland Cooperative Agreement on Mineral Development, 1990-1994
DISCLAIMER
The Geological Survey Division of the Mining and Mineral Development Branch, Government of Newfoundland and Labrador ('Geological Survey Division') provides this website to disseminate digital geological data and ancillary data. The Geological Survey Division retains the sole right and title to the original geoscience data and the information contained in any product thereby produced and provided. The Geological Survey Division makes available for public use open file reports, maps and digital geological data. These materials have not been formally edited or peer reviewed and are based upon preliminary data and evaluation. The Geological Survey Division assumes no legal liability or responsibility for any alterations, changes, representations or misrepresentations made by users or third parties with respect to the materials and original data. Users and third parties should consult with the Geological Survey Division to ensure the originality and correctness of the materials and original data provided. The users of these materials and original data agree not to provide a digital reproduction or copy of same to a third party. Furthermore, the Geological Survey Division assumes no liability of any nature or kind with respect to digital reproductions, copies of original products or for derivative products which may be made by or for third parties. Derivative products should acknowledge the source of the data upon which the products are based.
RECOMMENDED CITATION
(for downloaded database)
Newfoundland and Labrador Geological Survey. "Regional Lake Sediment Database." Newfoundland and Labrador GeoScience Atlas OnLine. Last update: 1995. https://geoatlas.gov.nl.ca/Default.htm. [fill in date downloaded].
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Aslin, G.E.M.
1976: The determination of arsenic and antimony in geological materials by flameless atomic absorption spectrophotometry. Journal of Geochemical Exploration, Volume 6, pages 321-330.
Boulanger, A., Evans, D.J.R. and Raby, B.F.
1975: Uranium analysis by neutron activation delayed neutron counting. Proceedings of the 7th annual Symposium of Canadian Mineral Analysts, Thunder Bay, Ontario, September 22-23, 1975.
Christopher, T.K.
1991: Mapping the anthropogenic effects of urbanization in the St. John's area using the inorganic geochemistry of lake sediments. B.Sc. honours thesis, Department of Earth Sciences, Memorial University of Newfoundland, 105 pages.
Chork, C.Y. and Mazzucchelli, R.H.
1989: Spatial filtering of exploration geochemical data using EDA and robust statistics. Journal of Geochemical Exploration, Volume 34, pages 221-224.
Colman-Sadd, S.P., Hayes, J.P. and Knight, I.
1990: Geology of the Island of Newfoundland. Newfoundland Department of Mines and Energy, Geological Survey Branch Map 90-01.
Davenport, P.H.
1988: The use of multi-element neutron activation analysis of organic lake sediment in geochemical exploration for gold. In Current Research, Newfoundland Department of Mines and Energy, Geological Survey Branch Report 88-1, pages 403-414.
Davenport, P.H., Christopher, T.K., Vardy, S. and Nolan, L.W.
1993: Geochemical mapping in Newfoundland and Labrador: its role in establishing baselines for the measurement of environmental change. Journal of Geochemical Exploration, Volume 49, pages 177-200.
Davenport, P.H., Honarvar, P., Hogan, A., Kilfoil, G.J., Nolan, L.W., Ash, J.S., Colman-Sadd, S.P., Hayes, J.P., Liverman, D.G.E., Kerr, A. and Evans, D.T.W.
1996: The Digital Geoscience Atlas of the Buchans - Robert's Arm Belt. Newfoundland Department of Mines and Energy, Geological Survey Digital Atlas 96-1, open file NFLD/2611, version 1.0, CD-ROM.
Davenport, P.H., Nolan, L.W. and Kilfoil, G.J.
1991: Image-processing of geochemical data to map geological structures and alteration zones. In "Exploration Geochemistry 1990", F. Mrna (Editor), Geological Survey of Prague, pages 57-61.
Davenport, P.H. and Nolan, L.W.
1987: Gold and associated elements in lake sediment from regional surveys in the Port aux Basques area (NTS 11O).
Newfoundland Department of Mines and Energy, Mineral Development Division, Open File NFLD/1582.
1988: Gold and associated elements in lake sediment from regional surveys in the Botwood map area (NTS 2E). Newfoundland Department of Mines, Mineral Development Division, Open File 2E/563.
1991a: Gold and associated elements in lake sediment from regional surveys in the Trepassey map area (NTS 1K). Newfoundland Department of Mines and Energy, Geological Survey, Open File 1K/25.
1991b: Gold and associated elements in lake sediment from regional surveys in the St. Lawrence map area (NTS 1L). Newfoundland Department of Mines and Energy, Geological Survey, Open File 1L/136.
Davenport, P.H., Nolan, L.W. and Hayes, J.P.
1988: Gold and associated elements in lake sediment from regional surveys in the Gander Lake map area (NTS 2D). Newfoundland Department of Mines, Geological Survey, Open File 2D/175.
1989: Gold and associated elements in lake sediment from regional surveys in the northwestern part of the Burgeo map area (NTS 11P). Newfoundland Department of Mines, Geological Survey, Open File 11P/137.
Davenport, P.H., Nolan, L.W., Hayes, J.P. and Liverman, D.G.E.
1989c: Gold and associated elements in lake sediment from regional surveys in the Sandy Lake map area (NTS 12H). Newfoundland Department of Mines and Energy, Geological Survey, Open File 12H/1012.
Davenport, P.H., Nolan, L.W., O'Brien, S.J. and Honarvar, P.
1990a: Gold and associated elements in lake sediment from regional geochemical surveys in the Belleoram map area (NTS 1M). Newfoundland Department of Mines and Energy, Geological Survey, Open File 1M/312.
Davenport, P.H., Nolan, L.W., Honarvar, P. and Hogan, A.P.
1990b: Gold and associated elements in lake sediment from regional geochemical surveys in the Red Indian Lake map area. Newfoundland Department of Mines and Energy, Geological Survey, Open File 12A/561.
Davenport, P.H., Nolan, L.W., Hayes, J.P. and Honarvar, P.
1990c: Gold and associated elements in lake sediment from regional geochemical surveys in the St. John's map area (NTS 1N). Newfoundland Department of Mines and Energy, Geological Survey, Open File 1N/499.
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Davenport, P.H., Honarvar, P. and Bruce, P.A.
1993a: Gold and associated elements in lake sediment from regional geochemical surveys in the Bonavista (2C) and Wesleyville (2F) areas. Newfoundland Department of Mines, Geological Survey, Open File Nfld/2273.
1993b: Gold and associated elements in lake sediment from regional geochemical surveys in the Stephenville (12B) and Bay of Islands (12G) areas. Newfoundland Department of Mines, Geological Survey, Open File Nfld/2274.
1994a: Gold and associated elements in lake sediment from regional geochemical surveys in the Port Saunders (12I & 2L) area. Newfoundland Department of Mines, Geological Survey, Open File Nfld/2275.
1994b: Gold and associated elements in lake sediment from regional geochemical surveys in the Blanc Sablon (12P) and St. Anthony (2M) areas. Newfoundland Department of Mines, Geological Survey, Open File Nfld/2276.
Ficklin, W.H.
1970: A rapid method for the determination of fluoride in rocks and soils, using an ion-selective electrode. U.S. Geological Survey paper 700C, pages C186-188.
Friske, P.W.B. and Hornbrook, E.H.W.
1991: Canada's National Geochemical Reconnaissance Programme. Transactions of the Institution of Mining and Metallurgy, Section B, pages B47-B56.
Friske, P.W.B., McCurdy, M.W., Lynch, J.J., Gross, H., Day, S.J., Adcock, S.W., Durham, C.C. and Karam, H.
1992a: National Geochemical Reconnaissance Lake Sediment and Water Data, Central Labrador (NTS 13F). Geological Survey of Canada open file 2471.
Friske, P.W.B., McCurdy, M.W., Day, S.J., Lynch, J.J., Gross, H., Durham, C.C. and Karam, H.
1992b: National Geochemical Reconnaissance Lake Sediment and Water Data, Central Labrador (NTS 13G). Geological Survey of Canada open file 2472.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Lynch, J.J. and Durham, C.C.
1993a: National Geochemical Reconnaissance Lake Sediment and Water Data, central Labrador (NTS 13E). Geological Survey of Canada open file 2474.
Friske, P.W.B., McCurdy, M.W., Day, S.J., Gross, H., Lynch, J.J. and Durham, C.C.
1993b: National Geochemical Reconnaissance Lake Sediment and Water Data, western Labrador (NTS 23H and part of 23G). Geological Survey of Canada open file 2475.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Lynch, J.J. and Durham, C.C.
1993c: National Geochemical Reconnaissance Lake Sediment and Water Data, central Labrador (NTS 13K). Geological Survey of Canada open file 2645.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Lynch, J.J. and Durham, C.C.
1993d: National Geochemical Reconnaissance Lake Sediment and Water Data, eastern Labrador (NTS 13I, 13J and 13O). Geological Survey of Canada open file 2646.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Lynch, J.J. and Durham, C.C.
1993e: National Geochemical Reconnaissance Lake Sediment and Water Data, central Labrador (NTS 13L). Geological Survey of Canada open file 2647.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Lynch, J.J. and Durham, C.C.
1993f: National Geochemical Reconnaissance Lake Sediment and Water Data, eastern Labrador (NTS 13N). Geological Survey of Canada open file 2648.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Lynch, J.J. and Durham, C.C.
1993g: National Geochemical Reconnaissance Lake Sediment and Water Data, west-central Labrador (NTS 13M). Geological Survey of Canada open file 2649.
Friske, P.W.B., McCurdy, M.W., Day, S.J., Gross, H., Lynch, J.J. and Durham, C.C.
1993h: National Geochemical Reconnaissance Lake Sediment and Water Data, southwestern Labrador (parts of NTS 22P, 23A and 23B). Geological Survey of Canada open file 2689.
Friske, P.W.B., McCurdy, M.W., Day, S.J., Gross, H., Lynch, J.J. and Durham, C.C.
1993i: National Geochemical Reconnaissance Lake Sediment and Water Data, northern Labrador (NTS 14C and parts of 214D and 24A). Geological Survey of Canada open file 2690.
Friske, P.W.B., McCurdy, M.W., Day, S.J., Gross, H., Lynch, J.J. and Durham, C.C.
1993j: National Geochemical Reconnaissance Lake Sediment and Water Data, northern Labrador (parts of NTS 14E, 14L, 24H and 24I). Geological Survey of Canada open file 2691.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Balma, R.G., Lynch, J.J. and Durham, C.C.
1994a: National Geochemical Reconnaissance Lake Sediment and Water Data, southeastern Labrador (NTS 3E, 13H). Geological Survey of Canada open file 2473.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Balma, R.G., Lynch, J.J. and Durham, C.C.
1994b: National Geochemical Reconnaissance Lake Sediment and Water Data, southeastern Labrador (NTS 3D, 13A and parts of 2M and 12P). Geological Survey of Canada open file 2790.
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Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Balma, R.G., Lynch, J.J. and Durham, C.C.
1994c: National Geochemical Reconnaissance Lake Sediment and Water Data, southern Labrador (NTS 13B). Geological Survey of Canada open file 2791.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Balma, R.G., Lynch, J.J. and Durham, C.C.
1994d: National Geochemical Reconnaissance Lake Sediment and Water Data, southern Labrador (NTS 13C). Geological Survey of Canada open file 2792.
Friske, P.W.B., McCurdy, M.W., Gross, H., Day, S.J., Balma, R.G., Lynch, J.J. and Durham, C.C.
1994e: National Geochemical Reconnaissance Lake Sediment and Water Data, southern Labrador (NTS 13D). Geological Survey of Canada open file 2793.
Garrett, R.G.
1969: The determination of sampling and analytical errors in exploration geochemistry. Economic Geology, Volume 64, pages 568-569.
1973: The determination of sampling and analytical errors in exploration geochemistry - a reply. Economic Geology, Volume 67, pages 28-283.
Geological Survey of Canada,
1988: Digital aeromagnetic data, on 9-track magnetic tape, for all onshore areas of the Province of Newfoundland and Labrador.
Geosoft Inc.
1991: The Geosoft Mapping System, Version 2.1: User's Manual. Geosoft Inc., Toronto.
Hall, G.E.M.
1979: A study of the stability of uranium in waters collected from variuos geological environments in Canada. In Current Research, part A, Geological Survey of Canada paper 79-1A, pages 361-365.
Hornbrook, E.H.W., Davenport, P.H. and Grant, D.R.
1975: Regional and detailed geochemical studies in glaciated terrain in Newfoundland. Newfoundland Department of Mines and Energy, Mineral Development Division Report 75-2, 116 pages.
Hornbrook, E.H.W. and Friske, P.W.B.
1989: National Geochemical Reconnaissance Lake Sediment and Water Data, West-Central Labrador (parts of 23I, 23J and 23O). Geological Survey of Canada open file 2037.
Jonasson, I.R., Lynch, J.J. and Trip, L.J.
1973: Field and laboratory methods used by the Geological Survey of Canada in geochemical surveys; No. 12, Mercury in Ores, Rocks, Soils, Sediments and water. Geological Survey of Canada paper 73-21.
Ramsey, M.H., Thompson, M. and Hale, M.
1992: Objective evaluation of precision requirements for geochemical analysis using robust statistics. Journal of Geochemical Exploration, volume 44, pages 23-36.
Wagenbauer, H.A., Riley, C.A. and Dawe, G.
1983: The Geochemical Laboratory. In Current Research, Newfoundland Department of Mines and Energy, Mineral Development Division Report 83-, pages 133-137.
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CONTACT
For further information on the regional lake sediment surveys please email:
GeoscienceOnline@gov.nl.ca
(Help File updated: April 2021)
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