Geochemistry: User's Guide

Please contact DGGS at with any feedback or questions.

Frequently Asked Questions (FAQs)


Frequently Asked Questions (FAQs)

What is this application?

This application is a web-based tool to discover and download Alaska geochemical data from multiple published sources. While the majority of the dataset has been harvested from DGGS publications and project files, many U.S. Bureau Mines and Bureau of Land Management publications and a small percentage of U.S. Geological Survey publications are also included. The database is continually updated as more data is collected and formatted for loading.

What type of geochemical data does this application contain?

This application provides you with raw data, so that you can perform any additional data quality checking, manipulation and secondary analysis on your own.

How do I use the search?

Geochemistry may be queried by geographic area, specific text, or a combination of area and text. The Search Bar at the top of the application allows for queries of single and multiple terms, where multiple terms without other query specifications are always searched with an implied Boolean "AND." Advanced search parameters include logical operators AND, OR, NOT (also "-" for NOT). Text within all the "non-dynamic" fields listed below may be queried through the Search Bar using the format of the examples searches below.

Note that a search on one element will also return data for other elements. Data in the application are organized by the original laboratory order for a given sample, where known. Original laboratory orders may link together multiple analytical suites, and all of these elements will be returned in the query results.

Example searches

The species search uses a dynamic field for searching for specific elements and oxides, (species_*) where the asterisk is replaced with the abbreviated species name. IMPORTANT! Species abbreviation must be lower case. For example, SiO2 MUST be sio2 in order for the search to work.

PLEASE NOTE: While typical whole rock analyses can be queried as a subset of the database fairly easily, in order to query a typical exploration geochemical suite of elements, we recommend narrowing your search geographically using the Area of Interest tool and then downloading all of the analyses for that area to ensure you receive all the trace element data.

How do I download the data?

After narrowing your search criteria, click on "Download All Results". You will be prompted to download a zip file containing comma delimited files (.csv) in two different views of the data; one is optimized for GIS (columnar format) and the other is better for analytical software (row format). The reference .csv file provides the supporting documentation available for both formats. The latitude and longitude coordinates in the download files are provided in the World Geodetic System 1984 (WGS84) datum. We recommend keeping your search criteria as restrictive as possible. Broad search parameters may result in an enormous amount of columns. Definitions of the fields are available in the application metadata.

The entire dataset may be selected and subsequently downloaded by searching on "*" or running an empty search.

Some of the chemical analyses show negative values. What does this mean?

By their nature, geochemical analysis values are positive numbers with a fixed precision. Most geochemical data tables use some text or symbol to indicate special conditions of a geochemical analysis value. These symbols have been replaced with negative values in order for the data to be used in GIS and analytical software that requires the values to be numeric. The negative values are coded to indicate the following situations.

Top of page

Appendix A: Search fields

Definitions of fields available in the public interface. The application metadata contains a complete list of fields and definitions.

Field name Search name Definition
Analysis ID id The unique identifier of the analysis
Analysis analysis Any terms inside the analysis record itself, e.g. the species (element or oxide names and abbreviations), the method, prep, the values, method categories, etc.
Citation citation Publication number or citation reference in which the analyses were originally published (e.g. RDF 2011-4)
Analysis Description description A description of the sample preparation and analytical methods used in the analysis
Sample Documentation documentation A text description of the rock or other material represented by the sample, if provided
Field Station Number fieldstation The field station number that identifies the field locality from which the sample was collected. For DGGS samples, it is usually in the format YYIINNN, where YY=two digit year of the field season the locality was established, II = Initials, or other text identifying the collector, and NNN a three digit sequential number for the field station.
Laboratory laboratory The name of the laboratory that performed the chemical analyses, if available.
Laboratory Number laboratory_number Sample number assigned by the lab
Project project A short descriptive name of the DGGS field project that was responsible for publication of geochemical sample analyses
Reference Number reference Usually a job batch number assigned by the laboratory. If not available, a unique text string is assigned by DGGS.
Reference Date reference_date The date or year that the analysis was completed or reported by the laboratory
Sample Number sample The sample number string assigned by the geologist or lab to identify the sample, it typically consists of the locality identifier, and other information that should assure a unique value. The sample number is a link to the Sample Detail page.
Sample Type sampletype The general class of material that describes the sample (e.g. "rock", "stream sediment")

Top of page

Appendix B: Sample Types

Field name Search name Values
Sample Type sampletype beach sediment
drill core
glacial debris/deposit
pan concentrate
placer con
placer sample
stream sediment

Top of page

Appendix C: Analysis Methods Categories

Analysis Method Category Associated Analysis Methods
AA AA-LL (Atomic Absorption - low level)
AAS (Atomic Absorption Spectroscopy)
HGAAS (Hydride Generation Atomic Absorption Spectrometry)
Calc Calculation
CIPW Norms CIPW Normative Calculation
Fire Assay FA (Fire Assay)
FA-AAS (Fire Assay - Atomic Absorption Spectroscopy)
FA-AES (Fire Assay - Atomic Emission Spectroscopy)
FA-AFS (Fire Assay - Atomic Fluorescence Spectroscopy)
FA-DCP (Fire Assay - Direct Couple Plasma)
FA-DCP (Fire Assay - Direct Couple Plasma Emission)
FA-DCP-AAS (Fire Assay - Direct Couple Plasma - Atomic Absorption Spectroscopy)
FA-DCP-DI (Fire Assay - Direct Couple Plasma - Direct Irradiation)
FA-GRAV (Fire Assay - Gravimetric)
FA-ICP (Fire Assay - Inductively Coupled Plasma )
FA-ICP-AES (Fire Assay - Inductively Coupled Plasma - Atomic Emission Spectroscopy)
FA-ICP-AES-MS (Fire Assay - Inductively Coupled Plasma - Atomic Emission Spectroscopy - Mass Spectrometry)
FA-ICP-AFS (Fire Assay - Inductively Coupled Plasma - Atomic Fluorescence Spectroscopy)
FA-ICP-MS (Fire Assay - Inductively Coupled Plasma - Mass Spectrometry)
FA-INAA (Fire Assay - Instrumental Neutron Activation Analysis)
FA-OES (Fire Assay - Optical Emission Spectrography)
M-FA (Metallic-Fire Assay)
ICP AES (Atomic Emission Spectroscopy)
ICP (Inductively Coupled Plasma)
ICP-AAS (Inductively Coupled Plasma - Atomic Absorption Spectroscopy)
ICP-AES (Inductively Coupled Plasma - Atomic Emission Spectroscopy)
ICP-AES-MS (Inductively Coupled Plasma - Atomic Emission Spectroscopy - Mass Spectrometry)
ICP-MS (Inductively Coupled Plasma - Mass Spectroscopy)
ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometry)
OES (Optical Emission Spectrography)
PES (Plasma Emission Spectrography)
NAA DNC-INAA (Delayed Neutron Counting Instrumental Neutron Activation Analysis)
NAA (Neutron Activation Analysis)
PGAMMA (Prompt Gamma Neutron Activation Analysis)
Other AFS (Atomic Fluorescence Spectroscopy)
ASES (Arc source emission spectrography)
COLOR (Colorimetry)
DCP (Direct Couple Plasma Emission)
EVOL (Evolution)
Fluor (Fluorometric)
GRAV (Gravimetric)
GRS (Gamma Ray Spectrometry)
IS (Infrared Spectroscopy)
RAD (Radiometric)
RECOV (Recovery)
SEM-ED-Xray (Scanning Electron Microscope - Energy-Dispersive X-Ray Spectroscopy)
SOES (Semiquantitative Optical Emission spectrometry)
SPEC (Spectrophotographic)
SPIon (Specific Ion)
SS (Semiquantitative Spectrographic)
TITR (Titrimetric)
UNK (Unknown)
WC (Wet Chemistry)
Volatiles CF (Combustion Furnace)
CVAA (Cold Vapor Atomic Absorption Spectroscopy)
Heat (Heating)
LECO (LECO Sulfur analysis)
LECO-C (LECO Induction Furnace Pyrolysis)
XRF SLAB-XRF (Slab X-Ray Fluorescence)
XRF (X-Ray Fluorescence)

Top of page

Appendix D: Sample Preparation Categories

Sample Preparation Category Associated Sample Preparations
Full Borate fusion
Carbonate fusion
Fire assay
Fire assay - aqua regia
Fused pellet
Fusion, dissolution, chloride precipitation
HNO3-HClO4-HF-HCl Digestion, HCl Leach
Lithium borate fusion
Lithium metaborate
Lithium metaborate fusion
Lithium metaborate fusion - HNO3-HCl dissolution
Lithium Metaborate/Lithium Tetraborate Fusion
Na2CO3-KNO3 fusion
NaOH fusion
Nickle Sulfide Fire Assay
NiS fusion
Peroxide fusion
Potassium hydroxide fusion
Potassium Pyrosulfate fusion
Pressed pellet
Pyrosulfate fusion
Sodium peroxide sinter
Sulfate fusion, dissolution, filtration
Thermal decomposition furnace
Near-total HF-H2SO4
HF-HNO3-HClO4 Acid Digestion, HCl Leach
HNO3-HCl hot extraction
Hot HSO4-H3BO4-H2SO4-H3PO4
Partial Acid
Ammonium Iodide
Aqua regia
Aqua regia - cold vapor
Aqua regia - Hydride
Carbonate sinter
Dilute acid
Hot acid leach
Hot HF+H2SO4+H3PO4+H3BO4
Multi-Acid Digestion and Hydride Generation
Multi-Acid MIBK
Multi-Acid Total Digestion

Top of page