National Geochemical Survey of Australia: Sample Preparation Manual  

Authors / CoAuthors

de Caritat, P. | Cooper, M. | Lech, M. | McPherson, A. | Thun, C.

Abstract

The National Geochemical Survey of Australia (NGSA) aims to collect samples from 1529 sites located in 1390 catchments (10% of which are sampled in duplicate) covering over 90% of Australia. At each site, two depth ranges are sampled, giving 3058 samples to be processed. Each sample results in 13 individually packaged sub-samples, meaning that 39,754 separate containers will be prepared, labelled, delivered to the laboratories or archived during the sample preparation phase of the project. Any excess fraction in the processing streams is kept for potential future use. The detailed procedures for preparing the NGSA samples in the laboratory are described with an overview of Quality Assessment/Quality Control and Operational Health and Safety measures also provided. There are three main parts to the sample preparation protocol. The first part is the Bulk Sample stream. The sample is received from the field, weighed, dried (for a minimum of 48h at 40°C) and sieved through a 4.75 mm mesh to remove any foreign material. The sample is then homogenised and split into two halves. One half is sealed and set aside for archiving for future analyses/investigations. The other half is split into sub-samples or aliquots for: 1. laser particle size analysis (LPSA), pH 1:5 (soil:water) and electrical conductivity (EC) 1:5 (soil:water) analysis; and 2. X-ray diffraction (XRD) analysis. The remainder of the bulk material is sieved through a 2mm mesh, and split into two portions (~20% and ~80%), which are processed in the following two streams. The second part is the Coarse Fraction stream. In this stream, the ~20% split of <2 mm sample prepared above is further split to prepare two aliquots for: - platinum group element (PGEs) analysis; and - gold (Au) analysis after aqua regia (AR) leach. The third part is the Fine Fraction stream. In this stream, the ~80% split of <2 mm sample prepared above is sifted using small stainless steel riffle splitters. The sample <75 um fraction is split into 5 different aliquots (splits) for different analyses. These aliquots are ranked in order of decreasing priority.

Product Type

document

eCat Id

68657

Contact for the resource

Keywords

• GA PublicationRecord

( Theme )

• geochemistry

( Theme )

• regolith

( Theme )

• mineral exploration

• AU

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_External

Publication Date

2009-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

Status

Purpose

Maintenance Information

unknown

Topic Category

geoscientificInformation

Series Information

Record 2009/008

Lineage

Unknown

Parent Information

Extents

[-44.0, -10.0, 112.0, 154.0]

Reference System

Spatial Resolution

Service Information

Associations

Downloads and Links

Download the Record (pdf)  

Source Information

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