Geophysical Surveying
The Geophysical Section is equipped with instruments for conducting Resistivity including resistivity imaging, Magnetic, Electro Magnetic (EM), Ground Penetration Radar (GPR) and Differential Global Positioning System (DGPS) Surveys for geological mapping, mineral exploration and engineering geological investigation. It is in the process of acquiring a Refraction Seismograph and other relevant equipment and necessary upgrading.
Resistivity surveys at Randeniya vein quartz deposit, magnesite and associated marble deposits at Wellawaya and sedimentary limestone deposit at Aruakkalu off Puttalam are few examples of main geophysical surveys conducted recently. It is also planned to conduct high resolution airborne magnetic, EM and radiometric survey with foreign technical assistance. The conducting of an integrated airborne survey would no doubt unravel valuable geo-scientific information of the country and reveal hither to unknown mineral resources. Equipment such as Envinet (16 Litre NaI crystal) car-borne gamma ray and hand held scintillometers are available for follow up investigations. With the recent acquisition of Resistivity Imaging and Ground Penetration Radar Systems, investigations of several archaeological sites were conducted.
Geophysics
The Geophysical Section is equipped with instruments for conducting Resistivity including resistivity imaging, Magnetic, Electro Magnetic (EM), Ground Penetration Radar (GPR) and Differential Global Positioning System (DGPS) Surveys for geological mapping, mineral exploration and engineering geological investigation. It is in the process of acquiring a Refraction Seismograph and other relevant equipment and necessary upgrading. Resistivity surveys at Randeniya vein quartz deposit, magnesite and associated marble deposits at Wellawaya and sedimentary limestone deposit at Aruakkalu off Puttalam are few examples of main geophysical surveys conducted recently. It is also planned to conduct high resolution airborne magnetic, EM and radiometric survey with foreign technical assistance. The conducting of an integrated airborne survey would no doubt unravel valuable geo-scientific information of the country and reveal hither to unknown mineral resources. Equipment such as Envinet (16 Litre NaI crystal) car-borne gamma ray and hand held scintillometers are available for follow up investigations.
With the recent acquisition of Resistivity Imaging and Ground Penetration Radar Systems, investigations of several archaeological sites were conducted.
Drilling
We are the pioneers in core drilling in Sri Lanka. The GSMB offers specialized services in drilling for mineral exploration, mining, engineering geological (geotechnical related works) work related to reservoirs, dams and tunnels, foundation testing etc. We assure collecting of soil and core samples with 90% recovery according to the ASTM and BS standards.
Drilling |
Method |
Maximum depth |
Auguring |
Hand auguring |
15m |
Power auguring |
30m |
|
Rotary core drilling in overburden |
Wash boring, dry block |
50m |
Diamond core drilling (Conventional, wireline, and top driven) |
HW, NX, NXM, BX, BXM, AX, AXM sizes HQ, NQ, BQ sizes |
100m 800m
|
The deepest core drill hole drilled during mid nineteen sixties into shale beds of Jurassic age at Andigama in Puttalam district was 1505 feet (≈450 m). Presently, we are capable to drill even deeper.
The following are some of the landmark events of our drilling history.
- Mineral Exploration;
- Seruwila (Copper & iron ore),
- Panirendawa, Wilagedera (iron ore),
- Aruakkalu (Limestone),
- Eppawala (Phosphate),
- Ambalantota (Sand),
- Andigama, Pallama, Tabbowa (shale),
- Dutch Bay, Aruakkalu, (Limestone),
- Cement raw material surveys in Pooneryn, Mankulam and Murunkan.
Engineering geological investigations;
- Gin ganga –Nilwala ganga tunnel trace,
- Moragahakanda irrigation and hydropower scheme,
- Kalu ganga dam and tunnel trace,
- North central diversion tunnel trace,
- Dam site investigations under North Western development scheme,
- Minipe anicut development project,
- Kukule ganga hydropower project,
- Samanala wewa hydropower project,
- Upper Kotmale (dam, spillway and tunnel trace),
- Foundation investigations for numerous multi-story buildings wind power plants etc.
Hand and Power auguring at;
- Dediyawala, Meetiyagoda, Piliyandala, for ball clay and kaolin,
- Nattandiya and Madampe areas for silica sand
- Geochemical survey;
- Twelve (12) 1:50,000 scale sheets,