3DGeoChem
3D Geochemical Model of Ore Deposits in the Skellefte District
This post-doctoral research project, undertaken in collaboration with colleagues at Boliden Mines, Exploration department, developed and presented a 3D assessment of metamorphosed and deformed, hydrothermally altered volcanic rocks, hosting the massive sulphide deposits of the Kristineberg area in the 1.9 Ga Skellefte mining district in northern Sweden, using six calculated alteration parameters:
- Ishikawa alteration index
- chlorite–carbonate–pyrite index
- calculated net mass changes in
- MgO
- SiO2
- Na2O
- Ba
Immobile element ratios were used to identify the precursor rock types for each sample, and this data, along with the above alteration indices and calculated mass change information forms the backbone of the 3D model, which highlights the complex relationship between the crosscutting geometries of the faults and altered rock units.
See our projectmovie here External link, opens in new window.
This video displays the results the Alteration Index 3D model. It begins with a still view of the entire modelled area. Then every other fault block fades out and the model is rotated to reveal the orebodies that are located within the missing fault blocks, as well as the full exterior of the still-visible blocks (A, C, E and G).
Then those fault blocks fade out to be replaced by the other set of fault blocks (B, D and F), which are rotated to provide an overview of the area.
Finally, each individual modelled shell level is displayed, one at a time, and rotated in turn, starting with the least altered, where:
grey = AI < 25
blue = AI 25-65
purple = AI 65-80
red = AI 80-90
dark red = AI > 90
To see the other video clips for the other alteration models, follow the link to the paper.
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