Stratigraphy and mineralization in the Mt. Read Volcanics, western Tasmania

Corbett, K. D.

doi:10.2113/gsecongeo.76.2.209

Cited by 31 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Darwin crater geology. Based on field mapping in this study and by R. J. Ford; 1:25,000 scale aerial photographs; Corbett and Brown (1975) and Corbett et al (1993).…”

Section: Methodology Scanning Electron Microscopy (Sem)mentioning

confidence: 96%

See 1 more Smart Citation

Geochemistry of Darwin glass and target rocks from Darwin crater, Tasmania, Australia

Howard

2008

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Abstract-Darwin glass formed about 800,000 years ago in western Tasmania, Australia. Target rocks at Darwin crater are quartzites and slates (Siluro-Devonian, Eldon Group). Analyses show 2 groups of glass, Average group 1 is composed of: SiO 2 (85%), Al 2 O 3 (7.3%), TiO 2 (0.05%), FeO (2.2%), MgO (0.9%), and K 2 O (1.8%). Group 2 has lower average SiO 2 (81.1%) and higher average Al 2 O 3 (8.2%). Group 2 is enriched in FeO (+1.5%), MgO (+1.3%) and Ni, Co, and Cr. Average Ni (416 ppm), Co (31 ppm), and Cr (162 ppm) in group 2 are beyond the range of sedimentary rocks. Glass and target rocks have concordant REE patterns (La/Lu = 5.9-10; Eu/Eu * = 0.55-0.65) and overlapping trace element abundances. 87 Sr/ 86 Sr ratios for the glasses (0.80778-0.81605) fall in the range (0.76481-1.1212) defined by the rock samples. ε-Nd results range from −13.57 to −15.86. Nd model ages range from 1.2-1.9 Ga (CHUR) and the glasses (1.2-1.5 Ga) fall within the range defined by the target samples. The 87 Sr/ 86 Sr versus 87 Rb/ 86 Sr regression age (411 ± 42 Ma) and initial ratio (0.725 ± 0.016), and the initial 43 Nd/ 144 Nd ratio (0.51153 ± 0.00011) and regression age (451 ± 140 Ma) indicate that the glasses have an inherited isotopic signal from the target rocks at Darwin crater. Mixing models using target rock compositions successfully model the glass for all elements except FeO, MgO, Ni, Co, and Cr in group 2. Mixing models using terrestrial ultramafic rocks fail to match the glass compositions and these enrichments may be related to the projectile.

show abstract

“…Darwin crater geology. Based on field mapping in this study and by R. J. Ford; 1:25,000 scale aerial photographs; Corbett and Brown (1975) and Corbett et al (1993).…”

Section: Methodology Scanning Electron Microscopy (Sem)mentioning

confidence: 96%

“…Geology of the Darwin glass strewn field. Based on Corbett and Brown (1975) and Corbett et al (1993).…”

Section: Stratigraphymentioning

confidence: 99%

Geochemistry of Darwin glass and target rocks from Darwin crater, Tasmania, Australia

Howard

2008

Meteorit & Planetary Scien

View full text Add to dashboard Cite

show abstract

“…The sequence of predominantly intermediate to silicic volcanic rocks hosts stratiform massive sulphides associated with disseminated epigenetic veining and stockworks (Corbett, 1981). Earlier interpretations suggested that the volcanic rocks were emplaced predominantly subaerially, with complex caldera-related faulting and subsidence locally allowing submarine conditions to prevail (Corbett, 1981), but a more recent facies analysis suggests that the entire volcanic pile was submarine (Corbett, 1992). The mineralization developed through the fracture-networks, and was locally exhaled onto the sea floor (Gemmell & Large, 1992).…”

Section: Comparisons and Discussionmentioning

confidence: 99%

Pre-Acadian copper mineralization in the English Lake District

1999

View full text Add to dashboard Cite

The Ordovician sedimentary and igneous rocks of the English Lake District host a widespread suite of epigenetic metalliferous veins dominated by copper sulphides with abundant arsenopyrite, pyrite and accessory galena and sphalerite. New field and microstructural evidence from examples of this suite at Coniston, Wasdale, Honister, Newlands and Borrowdale shows that the veins were strongly cleaved during the Early Devonian (Emsian) Acadian orogenic event. The principal evidence includes the continuity of wall-rock cleavage fabrics with pressure solution seams in the veins and consistently orientated cleavage through enclosed, rotated wall-rock fragments and chloritic mats. There is also widespread complex intracrystalline deformation in quartz, cataclasis of arsenopyrite and pyrite, fracturing and/or buckling of bladed hematite, and growth of quartz or mica-fibre strain fringes. Chalcopyrite was partially or totally remobilized, enabling it to migrate along quartz crystal boundaries, and invade brecciated pyrite. Previous K-Ar Early Devonian age determinations for the mineralization are considered to have been reset. The pre-Acadian age of this mineralization, its style and relationship to the volcanic rocks permits a genetic link with the final phases of Caradoc magmatism.

show abstract

“…The geology of western Tasmania has recently been reviewed by Cooper and Grindley (1982), Solomon (1981), Corbett (1981) and Williams (1978). The main Palaeozoic elements and locations of dated units are shown in Figs 1 and 2, and a stratigraphic column is shown in Fig.…”

Section: Geological Framework and Summary Of Known Tectono-thermal Evmentioning

confidence: 99%

“…Loftus-Hill et al 1967;Brathwaite 1970) are of doubtful significance. The sequence is faulted against the Crimson Creek Formation to the W (Green 1983), and the best lithological correlation appears to be with the Dundas Group (Williams et al 1976a;Corbett 1981;Green 1983).…”

Section: Crimson Creek Formationmentioning

confidence: 99%

Reconnaissance isotopic studies bearing on the tectonothermal history of Early Palaeozoic and Late Proterozoic sequences in western Tasmania

Adams

Black

Corbett³

et al. 1985

Australian Journal of Earth Sciences

Self Cite

View full text Add to dashboard Cite

Reconnaissance isotopic dating (K-Ar, Rb-Sr, U-Pb) of over 20 different units of Early Palaeozoic and Late Proterozoic age in western and northern Tasmania has assisted in clarifying some ages and relationships but has met with many problems. The Rb-Sr systems in most Cambrian rocks have been re-set or partially re-set by post-Cambrian tectonothermal events, particularly the midDevonian Tabberabberan Orogeny, and U-Pb zircon data show considerable scatter due to contamination by older zircon and to post-crystallization Pb loss. K-Ar dating, mainly of slates and schists, has been more successful in delineating major tectonothermal events, but spreads of ages due to incomplete re-setting are again evident in some cases. The investigation has demonstrated some of the difficulties involved in dating in this complex region. Slate ages from the Late Proterozoic Burnie and Oonah Formations and Rocky Cape Group fall in the 630-690 Ma range, and confirm that the Penguin Orogeny was a Proterozoic event which, although protracted, was not related to the generation of the Cambrian Mt Read Volcanics. Slates and schists from the Proterozoic metasedimentary sequences of the Tyennan Region give ages in the 540-610 Ma range, suggesting independence from the Rocky Cape Region and confirming the importance of the D3 event of Råheim and Compston (Lithos 10, 271-90, 1977). A considerable number of Ordovician ages (450-490 Ma) have been recorded from known Cambrian units, not all of which can reasonably be ascribed to partial Tabberabberan re-setting. Some of these are interpreted as indicating a significant thermal event, associated with some folding and cleavage formation, in the Late CambrianEarly Ordovician. Slates and schists produced by the Tabberabberan Orogeny show a spread of ages from about 390 Ma, near the indicated biostratigraphic position of the orogeny, to about 420 Ma (e.g. Rosebery Mine schists), suggesting that the Devonian tectonothermal activity may have been spread over some 30 Ma.

show abstract

Stratigraphy and mineralization in the Mt. Read Volcanics, western Tasmania

Cited by 31 publications

References 0 publications

Geochemistry of Darwin glass and target rocks from Darwin crater, Tasmania, Australia

Geochemistry of Darwin glass and target rocks from Darwin crater, Tasmania, Australia

Pre-Acadian copper mineralization in the English Lake District

Reconnaissance isotopic studies bearing on the tectonothermal history of Early Palaeozoic and Late Proterozoic sequences in western Tasmania

Contact Info

Product

Resources

About