BACHELOR  THESIS:  3D  modelling  of  hydrothermal  altera>on  and  Au  mineralisa>on  in  the  Nuuluk  area  

Tartoq  gold  province  (SW  Greenland)  

Sara  E.  Hoffritz  Done  in  co-­‐opera>on  with  University  of  Copenhagen  and  Geological  Survey  of  Denmark  and  Greenland  

Nuuluk  

Figur Map showing location of Nuuluk in SW Greenland and the regional geology. Map is modified after GEUS (figure: Henriksen 1968, Escher og Jensen 1974, Jensen 1975)

Figur  Map  of  the  loca>on  of  different  drill  cores  (red  dots),  both  diamond  drilling  in  the  west  and  winkie  drillings  in  the  east  along  with  surface  samples  shown  by  their  gold  value  (Figur:  King,1985)  

Background  

•  More  than  40  years  of  explora>on  •  Two  parallel  altera>on  zones  of  old  meta-­‐volcanics  in  a  classic  greenstone  belt  which  has  been  hydrothermally  altered  by  carboniferous  fluids    

•  Rock  types  are  schist  and  hydrothermal  altered  meta-­‐volcanics  

•  12.30  ppm  in  the  Eastern  zone  

•  6.63  ppm  in  the  Western  zone  

METHODE  

Cross  sec>ons  

DH5 125m

surfaceAu (78 ppb, projected)

Au (132 ppb, projected)

Au (730 ppb/2m)Au (217 ppb/2m)

West East

Pro!le A

DH1 134 m

DH2109 m

Au (6.65 ppm/2m)

Au (86 ppb/4m)Au (516 ppb/2m)

Au (61 ppb) Au (887 ppb)

DH3

DH4

surface

Au (127 ppb/4m)

Au (68 ppb/4m)

97 m

109 m

West East

DH1 & DH2 DH3 & DH4

DH5

Geochemical  features  Profile log and sample analysis

Imported  data  

From  reports  from  Nunaoil,  Greenex  and  GEUS  

•  Drill  hole  data  – Loca>on,  depth,  azimuth  and  dip  – Lithology  – Measurements  of  Au,  As  and  Cu  

– Structural  measurements  

•  Surface  samples  -­‐>  topography  

Lithology  

Lithology  

Lithology  -­‐  Structures  

Gold  occurrences  

Western  upper  zone  

Eastern,  northern  zone  

Western  lower  zone   Eastern,  southern  zone  

HALOES: Red: 95< ppb (!) Orange: 80-95 ppb Yellow: 60-80 ppb Bright: 50-60 ppb

Lithology  +  Gold  occurences  

Results  •  Modelling  of  gold  volumes  are  possible  in  spite  of  low  values  and  gives  a  good  idea  over  the  poten>al  in  the  area    

•  The  gold  is  in  boundary  zones  with  lower  stability  –  but  in  different  rock  types  –  structures  ?  

•  There  are  at  least  four  mineraliza>on  zones  •  Gold  correlates  with  As  and  Cu  •  There  is  a  connec>on  with  high  gold  values  and  the  graphite-­‐  and  magne>te  schist  

•  Old  and  new  data  can  give  a  3D  view  of  the  geometry  of  the  gold  occurrences  

•  More  data  is  needed  •  GEUS:  Project  re-­‐opened  and  area  will  be  more  inves>gated  next  field  season