Authors / CoAuthors
Fraser, G.L. | Bagas, L. | Huston, D.
Abstract
At the Sandpiper gold deposit in the Tanami region of northern Australia sericite is intimately intergrown with arsenopyrite in gold-bearing quartz veins and breccias, suggesting sericite crystallisation synchronous with gold-bearing fluid flow. This ore-stage sericite yields a 40Ar/39Ar plateau age of 1785 ± 16 Ma (1?? including all known systematic uncertainties). Recalculation using revised and more precise values for the 40K decay constants and the age of the Fish Canyon Sanidine standard shifts the age to 1792 ± 6 Ma (1???including all known systematic uncertainties). Given the possibility of post-mineralization isotopic resetting this age can be conservatively interpreted as a minimum constraint on the timing of gold deposition although, given local geological relationships and estimates for the argon retentivity of white mica, we consider complete isotopic resetting to be unlikely. The preferred interpretation is, therefore, that the sericite 40Ar/39Ar age indicates the timing of gold mineralization. The sericite age accords with a limited dataset of 207Pb/206Pb xenotime ages of ~1800 Ma from other gold deposits in the Tanami region, interpreted as mineralization ages. The agreement between independently-derived ages from several gold deposits lends support for a widespread gold-mineralizing event at ~1800 Ma in the Tanami region.
Product Type
nonGeographicDataset
eCat Id
72057
Contact for the resource
Custodian
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
-
- External Publication
- ( Theme )
-
- geochronology
- ( Theme )
-
- gold
- ( Theme )
-
- mineral deposits
- Australian and New Zealand Standard Research Classification (ANZSRC)
-
- Earth Sciences
-
- Published_Internal
Publication Date
2011-06-09T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
unknown
Topic Category
geoscientificInformation
Series Information
Lineage
Unknown
Parent Information
Extents
Reference System
Spatial Resolution
Service Information
Associations
Downloads and Links
Source Information
Source data not available.