Naschwitz, W and Van Moort, JC, Geochemistry of wallrock alteration, Rosebery, Tasmania, Australia, Applied Geochemistry, 6, (3) pp. 267-278. ISSN 0883-2927 (1991) [Refereed Article]
© 1991 Pergamon Press plc
The Rosebery ore deposit consists of two adjacent massive sulphide bodies hosted in an easterly dipping lens of sedimentary rocks within a pile of acid pyroclastic rocks of Cambrian age. Both orebodies are underlain by zones of intense alteration which mark the path of the metal-bearing fluids. The southern vent is exposed on the surface. Its alteration zone extends for up to 2 km in a N-S direction and has a maximum E-W width of ∼ 700 m.
The footwall and, to a minor degree, the hanging wall have been subjected to hydrothermal alteration. In the field, this alteration is marked by plagioclase-free quartz-sericite-(chlorite) schists which exhibit two different facies: siliceous augen schists and thinly cleaved K-feldspar-bearing schists.
Samples can be grouped geochemically into altered and unaltered volcanics despite the large variation in chemical composition within each group. This classification is supported by cluster analysis. In the vicinity of the deposit, concentrations of SiO2, K2O and Rb are anomalously high while contents of Al2O3, Na2O, TiO2, CaO, Sr, Zr, Y and Nb show a significant depletion. At the outer limit of the alteration halo the hydrothermal influence is more easily detected geochemically than geologically.
|Item Type:||Refereed Article|
|Research Division:||Earth Sciences|
|Research Field:||Exploration Geochemistry|
|Objective Division:||Expanding Knowledge|
|Objective Group:||Expanding Knowledge|
|Objective Field:||Expanding Knowledge in the Earth Sciences|
|UTAS Author:||Van Moort, JC (Dr Jan Van Moort)|
|Web of Science® Times Cited:||4|
|Deposited By:||Earth Sciences|
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