| 24319 |
Creator |
4989dd10527e94ef140e45e8c9fb07e6 |
| 24319 |
Creator |
ext-3af2c51f0cd9129b96ae08bfc61fe7a3 |
| 24319 |
Creator |
ext-c806ffbcf9f238411510328d4eb67570 |
| 24319 |
Creator |
ext-dda4a680c2d00d283254783d135dc407 |
| 24319 |
Date |
2010-09 |
| 24319 |
Is Part Of |
p00092541 |
| 24319 |
Is Part Of |
repository |
| 24319 |
abstract |
Analyses of the Re–Os isotope system and PGE abundances have been used to investigate
the timing and origin of mineralisation in the Vaal Reefs section of the Witwatersrand
Basin, the world's largest gold deposit. Consistent interelement PGE fractionation
in both organic and sulphide phases intimately associated with gold mineralisation
suggests that the Re–Os isotope system was fractionated during gold mobilisation.
The Re–Os isotope data on organic separates intimately associated with the gold in
this part of the basin indicate open system behaviour until ˜2.26 ± 0.19 Ga (2σ),
of the order of 450 Myr younger than the minimum age of sedimentation. The overlying
Ventersdorp Volcanics preserve a Re–Os isochron age of 2.43 ± 0.21 Ga, ˜250 Ma younger
than their U–Pb zircon emplacement age. These data indicate substantial post-sedimentary
noble metal mobility within portions of the Witwatersrand Basin. Re–Os model age calculations
on Os-rich fractions suggest that noble metals were derived from a 3.0–3.1 Ga terrain
of granite–greenstone affinities, significantly younger than the Barberton Greenstone
Belt. These data support a hybrid model involving post-depositional mobilisation of
ancient, probably detrital, noble metals for the origin of mineralisation in this
part of the Witwatersrand Basin. Such a model is applicable to other areas of gold
mineralisation in the basin that display similar textural characteristics and geochemistry. |
| 24319 |
authorList |
authors |
| 24319 |
issue |
1-2 |
| 24319 |
status |
peerReviewed |
| 24319 |
volume |
276 |
| 24319 |
type |
AcademicArticle |
| 24319 |
type |
Article |
| 24319 |
label |
Schaefer, B. F.; Pearson, D. G.; Rogers, N. W. and Barnicoat, A. C. (2010). Re–Os
isotope and PGE constraints on the timing and origin of gold mineralisation in the
Witwatersrand Basin. Chemical Geology, 276(1-2) pp. 88–94. |
| 24319 |
label |
Schaefer, B. F.; Pearson, D. G.; Rogers, N. W. and Barnicoat, A. C. (2010). Re–Os
isotope and PGE constraints on the timing and origin of gold mineralisation in the
Witwatersrand Basin. Chemical Geology, 276(1-2) pp. 88–94. |
| 24319 |
Title |
Re–Os isotope and PGE constraints on the timing and origin of gold mineralisation
in the Witwatersrand Basin |
| 24319 |
in dataset |
oro |