Permo-Carboniferous gold epoch of northeast Queensland
Titel:
Permo-Carboniferous gold epoch of northeast Queensland
Auteur:
Perkins, C. Kennedy, A. K.
Verschenen in:
Australian journal of earth sciences
Paginering:
Jaargang 45 (1998) nr. 2 pagina's 185-200
Jaar:
1998-04
Inhoud:
The 40Ar/39Ar and U-Pb methods of isotopic dating have been used to determine the age of alteration minerals and host rocks from a number of Permo-Carboniferous Au deposits in the Tasman Fold Belt system of northeast Queensland. There was a continuum in porphyry-style Au mineralisation from ca 330 to 290 Ma, which post-dates epithermal Au in the Eastern Basin sequence of the Drummond Basin. Porphyry-style Au at Kidston, and the Buck Reef, Ravenswood, formed at ca 330 Ma. The Red Dome and Mungana skarns were deposited at ca 320-310 Ma and ca 310 Ma, respectively. The Au mineralisation at Mt Wright, and in the quartz-sulfide veins, Ravenswood, was emplaced at ca 310-305 Ma. The youngest porphyry-style Au deposit is Mt Leyshon, which probably formed at ca 290 Ma. Where high-level intrusions are associated with Au, magmatism and mineralisation are, in general, essentially coeval. The age of the host rocks to the Permo-Carboniferous Au deposits is variable, and may be more than 150 million years older than the mineralisation. The plutonic-style Au deposit at Charters Towers is significantly older than the porphyry systems, and formed at ca 414Ma.
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