Database creation, data quality assessment, and geochemical maps (phase V, deliverable 59)—Final report on compilation and validation of geochemical data: Chapter D in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

Open-File Report 2013-1280- D
Prepared in cooperation with the Ministry of Petroleum, Energy, and Mines of the Islamic Republic of Mauritania
By: , and 

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Abstract

Under the World Bank-funded Second Projet de Renforcement Institutionnel du Secteur Minier de la Republique Islamique de Mauritanie (PRISM-II), this Phase V geochemistry report follows earlier Phase I and Phase II summary reports on geochemical data (U.S. Geological Survey, 2007 and Eppinger, 2007; respectively). All the reports are based on evaluations of geochemical data collected in 1999-2004 under an earlier World Bank program (PRISM-I) by the British Geological Survey (BGS) and the Bureau de Recherches Géologiques et Minières (BRGM) for the Government of Mauritania. There are no associated Phase III or IV reports.

The geochemical sample media collected by the BGS and BRGM under the PRISM-I contract included rock, sediment, regolith, and soil samples. Details on sample collection procedures are in unpublished reports available from PRISM. These samples were analyzed under PRISM-I contract by ALS Chemex Laboratories using various combinations of modern methods including fire-assay inductively coupled plasma-atomic emission spectrometry (ICPAES) and ICP-mass spectrometry (ICP-MS) for Au; multi-acid digestion, atomic absorption spectroscopy (AAS) for Ag and As; 47-element, four-acid digestion, ICP-MS; 27-element, fouracid digestion, ICP-AES; special four-acid ICP-MS techniques for Pt and B; fire assay followed by ICP-AES for platinum-group elements; whole-rock analyses by wavelength dispersive X-ray fluorescence (XRF); special techniques for loss-on-ignition, inorganic C, and total S; and special ore-grade AAS techniques for Ag, Au, Cu, Ni, Pb, and Zn. Around 30,000 samples were analyzed by at least one technique. However, it is stressed here that: (1) there was no common sample medium collected at all sites, likely due to the vast geological and geomorphologic differences across the country, (2) the sample site distribution is very irregular, likely due in part to access constraints and sand dune cover, and (3) there was no common across-the-board trace element analytical package used for all samples. These three aspects fundamentally affect the ability to produce country-wide geochemical maps of Mauritania. Gold (Au), silver (Ag), and arsenic (As) were the three elements that were most commonly analyzed.

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Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Database creation, data quality assessment, and geochemical maps (phase V, deliverable 59)—Final report on compilation and validation of geochemical data: Chapter D in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)
Series title Open-File Report
Series number 2013-1280
Chapter D
DOI 10.3133/ofr20131280D
Year Published 2015
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Central Mineral and Environmental Resources Science Center
Description viii, 52 p.
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II) (Open File Report 2013-1280)
Country Mauritania
Online Only (Y/N) N
Additional Online Files (Y/N) N