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Details for article 8 of 8 found articles
| Title: |
Stable isotope, petrological, and fluid inclusion studies of minor mineral deposits from the McArthur Basin: Implications for the genesis of some sediment-hosted base metal mineralization from the Northern Territory |
| Author: |
Muir, M. D. Donnelly, T. H. Wilkins, R. W. T. Armstrong, K. J. |
| Appeared in: |
Australian journal of earth sciences |
| Paging: | Volume 32 (1985) nr. 3 pages 239-260 |
| Year: |
1985-09 |
| Contents: |
The geology, stable isotopes and fluid inclusions from mineralized and unmineralized Middle Proterozoic sequences of the McArthur Basin, Northern Territory, have been studied at Eastern Creek, Bulman Mines, Beetle Springs, and other localities in the McArthur Basin where disseminated sulphides in unmineralized black shales were available from drill core. At Eastern Creek, galena and minor chalcopyrite (δ34S+3.6 to +11.2%o) occur in an evaporitic sedimentary sequence. Barite (δ34S+18.4 to +24.7%o) also occurs, and saline brines are trapped along healed fractures in the barite. Pressure-corrected trapping temperatures in the barite (95-138°C), and in vein dolomite (158-168°C) agree with temperature estimates from the degree of maturation of the sedimentary organic matter. The δ18O and δ13CCo2 values of the mineralizing fluid were calculated to be +3.5 to +4.5%o and -2.7%o, respectively. Sedimentary dolomite has restricted δ13C and δ18O ranges, within the reported ranges for non-mineralized Middle Proterozoic dolomite. An ore formation model developed for Eastern Creek, in which a basinal fluid at about 200°C carrying base metals and sulphide was released from underlying sediments during local fault movement, may be applicable to a number of other deposits. The mineralization deposited from these fluids occurs only below the pre-Roper Group unconformity, implying that it may be older than the basal Roper Group. The δ34S values of iron sulphides in fine grained black dolostones (not associated with mineral deposits) from the McArthur Basin were assessed in the light of the values found for sulphides in modern organic-rich sedimentary environments. The data so obtained suggest that the considerable concentration of iron sulphide in the mineral deposits formed, at least in part, from heated basinal waters and that disseminated iron sulphides remote from mineralization also formed from a similar source. |
| Publisher: |
Taylor & Francis |
| Source file: |
Elektronische Wetenschappelijke Tijdschriften |
Details for article 8 of 8 found articles
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