Tanzania has a reconnaissance geochemical survey coverage at various scales. Most of the geochemical surveys were carried out by exploration and mining companies and organizations such as UNDP, Western Rift Exploration, BGR, BHP, JICA, SIDA SAREC and GST. The sampling media and elements analysed vary considerably between the different surveys depending on the objectives.
Available geochemical data at GST and analytical methods
Geochemical survey in Tanzania
GST is conducting geochemical survey at varying scales and sampling density, using different sampling media like stream sediments, soil and water. In addition GST is producing hard and soft copies of maps and data in various formats. Maps are presented in different formats such as dots colour surfaces and integrated with other data sets (geophysical, geological).
Apart from GST, geochemical surveys has been carried out by exploration and mining companies including Williamsons Diamonds, Western Rift Exploration in the Rukwa-Kigoma areas and UNDP and BHP on the western part of Lake Victoria. In addition, there has been several geochemical surveys conducted by organisations under joint programmes with the Government of Tanzania such as BGR gold and base metals project, JICA and SIDA SAREC. The sampling media, density and elements analysed vary considerably between the different surveys depending on the purpose of the project and interest (available geochemical data)
The geochemical data generated by GST, mining/exploration companies and organisations is available in digital and hard copies
- Countrywide low resolution airborne geophysical surveys were conducted by Geosurvey International (GmbH) in 1977 to 1979.
- High-altitude (200 m) and 1 km line spacing airborne geophysical mapping.
- Data available in QDS-wise as raw or/and processed. The data include: magnetics and radiometrics.
Systematic high resolution airborne geophysical survey conducted in selected areas by mineral exploration companies and other agencies such as BGR, UNDP, Geological Survey of Tanzania through the Geological Survey of Finland (GTK) as a Contractor (index map)
The new high resolution airborne geophysical data has been acquired by GTK in 2003, at 200m line spacing and 45 m flight altitude (see technical specifications)
Measured geophysical parameters:
- Magnetic total field
- Electromagnetic field with two or four frequencies
- Earth´s gamma radiation (K, U, Th and total radiation) DEM
The current regional geological mapping programme is focused on more thematic, project oriented data capture, interpretation and product delivery aimed at maximum attraction to the stakeholders.
- Main focus to produce basic geo-data and information for mineral exploration, environmental studies and land use
- Standardization and regularly updating data to provide seamless national coverage at any desired scale.
- Mapping of mineral resource targets according to areas with high potential for investment.
Past mapping and publications
- Geological maps published at a scale of 1:250,000 as degree sheets (DS 17 Kahama, DS 18 Shinyanga, DS 29 Singida and DS 52 Dodoma). Coverage is 3% of the total 322 QDS divisions of the country
- Geological maps published at 1:125,000 scale with a coverage of 48% of the total QDS
Present mapping and publications
- GST is currently mapping and publishing geological maps at a scale of 1:100 000 with coverage of 29% of the total QDS and the maps are available in digital format (see index map )
- Geological maps integrate geophysical, geochemical and geological data LandSat images and DEM.
- Old geological maps are being updated and published by adding value through field checks and incorporating new information (geophysical, geochemical, LandSat images and mineral occurrences)
GST's mapping programmes produce basic information for the needs of the mineral sector (exploration and mining ventures), land use planning, construction industry, environmental studies and other economic sectors.
GST's mapping programmes produce basic information for the needs of the mineral sector (exploration and mining ventures), land use planning, construction industry, environmental studies and other sectors of the economy. 85 % of the entire country has been geologically mapped. This has generated basic geological and mineralogical data and information used by investors in the mining sector and other sectors of the economy.
The current status of geological mapping is indicated in the index map: progress in geological mapping