1. ROSEBEL GOLDMINES SURINAME
Welcome
IAMGOLD
ROSEBEL GOLDMINES SURINAME
REGIONAL EXPLORATION

2. STRUCTURE OF PRESENTATION
Introduction
Geology and property geology
Weathering profile
Goldmobilization and mushroom effect
Exploration

3. INTRODUCTION Regional Exploration Find new targets for the mine
Active in and out of the mine-site
Working areas
Mine-site; J-zone, Spin-zone, Blauwe Tent etc
Koemboekreek en Kraboedoin
Sarakreek

4. PROPERTY GEOLOGY

5. GEOLOGY
The Rosebel concession lies within the Lower Proterozoic Guiana Shield, which stretches from the Amazon River in Brazil to the Orinoco River in Venezuela.
The Suriname portion of the shield consists of distinct belts of low-grade metamorphic rocks, separated by large areas underlain by granites and gneisses.

7. LOWER PROTEROZOIC GEOLOGICAL UNITS OF SURINAME
Rock unit
Age
Granitoid-Volcanic complex
1923 ± 55 Ma
Marowijne group
2000 ± 40 Ma
Coeroeni Group
2001 ± 97 Ma
Falawatra group
2026 ± 20 Ma

8. MAROWIJNE GROUP Paramaka Formation Armina Formation Rosebel Formation
(Basic to intermediate volcanic)
Armina Formation
(deepmarine sediments and volcanics)
Rosebel Formation
(Shallow marine-continental sediments)

10. WEATHERING
Chemical weathering
Mechanical weathering

11. TYPICAL WEATHERING PROFILE (TROPICS)
Horizon
Thickness
(meters)
Chemistry
Weathered Rock
Pisolitic clay zone
Massive clay zone
Mottled zone
0 - 3
0 - 10
2 - 10
Enriched in Fe2O3, depleted in SiO2
Enriched in Fe2O3, Al2O3, depleted in SiO2
Saprolite
Transition zone
5 - 80
Enriched in Al2O3, depleted in SiO2
Fresh rock
Variable

12. TRANSITIONAL ZONE
Grading from slightly weathered rock through to saprolite
Primary minerals are pseudomorphically replaced by weathering products (such as kaolinite)

13. SAPROLITE
Most weatherable primary minerals have been altered to secondary minerals such as kaolinite, goethite or amorphous iron oxyhydroxides.
Weathering is isovolumetric
The original rock fabric is preserved

14. MOTTLED ZONE Hydrated, clay-rich horizon
Contains vertical stripes and mottles of hydrated iron oxides
Water percolation creates a series of voids and channels, which can become filled with secondary kaolinite.
All original rock fabric is destroyed.

15. MASSIVE CLAYZONE Featureless Brick red clay
Containing less than 10 percent iron oxide concretions and pisolites

16. PISOLITIC CLAYZONE Featureless Brick red clay
Containing 10 to 95 percent iron oxide concretions and pisolites
Continued pisolite growth and cementation will eventually lead to development of duricrust

17. GOLD MOBILIZATION A leaching process takes place
Light material (such as clays) leach
Heavy material (such as gold) gets concentrated on the top layers
Which will eventually result in…

18. MUSHROOM EFFECT

19. EXPLORATION
To show indications, cheap and fast resulting methods are used
To define the ore-body more effective and structured methods are used

20. EXPLORATION METHODS Panning Mapping of porknocking pits BLEG sampling
Augering
Fieldmapping
Trenching
Diamond drilling

21. PANNING

22. MAPPING OF PORKNOCKING-PITS
Porknocking-pits indicate areas containing/contained gold
Using a GPS the boundaries can be mapped
While mapping the area, the source of gold can be determined (primary gold or alluvial gold)

23. BLEG SAMPLING BLEG = Bulk Leach Extractable Gold
After panning the concentrate of heavy minerals is sent to the lab
Gold is dissolved by cyanide and concentrated by extraction into an organic solvent.

24. AUGERING
An auger is a device for moving material by means of a rotating helical flighting.
A drill bit uses this mechanism to remove shavings from a hole being drilled.

25. AUGER-SAMPLING At first When anomaly results are received
A large grid is augered with 400 meter spacing
At each station (with 25 meter spacing) samples are taken from the first 2 meters
When anomaly results are received
Around this anomaly a smaller grid is sampled
Sampling takes place each meter until 5 meter (deepauger)

26. AUGER-PROCEDURE Samples are taken from each meter
Therefore each each meter is:
Logged (using the augerlogsheet)
Sampled
ID-ed

27. AUGER-LOGSHEET

28. SAMPLING Each meter At the end of meter Homogenized Quartered
250 grams sample taken to sent for lab
And a small amount in a chiptray for reference and further analysis

29. TRENCHING A trench is a type of excavation in the ground
After studying assay results orientation and location of trench is determined

30. WHY TRENCHING? Create outcrops
Study controls of gold-mineralization and gold-mobilization
Determine if future drilling is needed
Study orientations of bedding and quartzveins
Determine how and at which orientation the possible drilling has to be done

33. DIAMOND DRILLING Diamond drilling is very expensive
Advantage is that you will get in situ material in fresh rock
After analyzing auger data and field-mapping data a drill spot is determined in the field

34. The samples from augering, diamond drilling etc… are afterwards sent to the lab for analyzing
RGM Lab (on site)
The Assay Lab (Paramaribo)
Omai lab (Guyana)

35. DOES ANYONE HAVE
QUESTIONS?!

36. THANK YOU…
FOR YOUR ATTENTION