Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-26T09:59:48.710Z Has data issue: false hasContentIssue false
  • English
  • Français

The Cretaceous volcanic-plutonic province of the central Queensland (Australia) coast—a rift related ‘calc-alkaline’ province

Published online by Cambridge University Press:  03 November 2011

A. Ewart ,
R. W. Schon  and
B. W. Chappell
A. Ewart
Affiliation:
A. Ewart and R. W. Schon, Department of Earth Sciences, University of Queensland, St Lucia, Queensland 4072, Australia
B. W. Chappell
Affiliation:
B. W. Chappell, Department of Geology, Australian National University, Canberra, A.C.T. 2601, Australia
Get access Rights & Permissions [Opens in a new window]

Abstract

Silicic and minor intermediate and mafic pyroclastics, lavas, and dykes occupy a NW-trending zone through the Whitsunday, Cumberland and Northumberland Island groups, and locally areas on the adjacent mainland, over a distance of more than 300 km along the central Queensland coast. K-Ar and Rb-Sr data indicate an age range of 95–132 Ma, with the main activity approximately between 105–120 Ma; there is, however, evidence for easterly increasing ages. Comagmatic granites, some clearly intrusive into the volcanics, occur together with two localised areas of Triassic potassic granites (229 Ma), that form the immediate basement.

The volcanics are dominantly rhyolitic to dacitic lithic ignimbrites, with intercalated surge and bedded tuffs, accretionary lapilli tuffs, and lag deposits. Associated rock types include isolated rhyolitic and dacitic domes, and volumetrically minor andesite and rare basalt flows. The sequence is cut by abundant dykes, especially in the northern region and adjacent mainland, ranging from dolerite through andesite, dacite and rhyolite. Dyke orientations show maxima between NW-NNE. Isotope data, similarities in petrography and mineralogy, and alteration patterns all suggest dyke intrusion to be broadly contemporaneous with volcanism. The thickness of the volcanics is unconstrained, although in the Whitsunday area, minimum thicknesses of >1 km are inferred. Eruptive centres are believed to occur throughout the region, and include at least two areas of caldera-style collapse. The sequences are thus considered as predominantly intracaldera.

The phenocryst mineralogy is similar to modern “orogenic” volcanics. Phases include plagioclase, augite, hypersthene (uralitised), magnetite, ilmenite, with less common hornblende, and even rarer quartz, sanidine, and biotite. Fe-enriched compositions only develop in some high-silica rhyolites. The granites range from quartz diorite to granite s.s., and some contain spectacular concentrations of partially disaggregated dioritic inclusions.

Chemically, the suite ranges continuously from basalt to high-silica rhyolite, with calc-alkali to high-K affinities, and geochemical signatures similar to modern subduction-related magmas. Only the high-silica rhyolites and granites exhibit evidence of extensive fractional crystallisation (e.g. pronounced Eu anomalies). Variation within the suite can only satisfactorily be modelled in terms of two component mixing, with superimposed crystal fractionation. Nd and Sr isotope compositions are relatively coherent, with εNd + 2·2 to +7·3, and ISr (calculated at 110 and 115 Ma) 0·7031-0·7044. These are relatively primitive, and imply mantle and/or newly accreted crustal magma sources.

The two end-members proposed are within-plate tholeiitic melt, and ?low-silica rhyolitic melts generated by partial fusion of Permian (to ?Carboniferous) arc and arc basement. The arc-like geochemistry is thus considered to be source inherited. The tectonic setting for Cretaceous volcanism is correlated with updoming and basin rifting during the early stages of continental breakup, culminating in the opening of the Tasman Basin. Cretaceous volcanism is also recognised in the Maryborough Basin (S Queensland), the Lord Howe Rise, and New Caledonia, indicating the regional extent of volcanism associated with the complex breakup of the eastern Australasian continent margin.

Keywords

riftingsilicic volcanismpyroclasticsisotopestrace elementsCretaceouscrustal evolutionSW Pacific
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 83 , Issue 1-2: Second Hutton Symposium: The Origin of Granites and Related Rocks , 1992 , pp. 327 - 345
Copyright
Copyright © Royal Society of Edinburgh 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barley, M. E. 1987. Origin and evolution of Mid-Cretaceous, garnet-bearing, intermediate and silicic volanics from Canterbury, New Zealand. J VOLCANOL GEOTHERM RES 32, 247–67..Google Scholar
Blundy, J. D. & Holland, T. J. B. 1990. Calcic amphibole equilibria and a new amphibole-plagioclase geothermometer. CONTRIB MINERAL PETROL 104, 208–24.CrossRefGoogle Scholar
Burns, R. E. & Andrews, et al. 1973. Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Government Printing office) 21, 197–269.Google Scholar
Clarke, D. E., Paine, A. G. L. & Jensen, A. R. 1971. Geology of the Proserpine 1:250,000 Sheet area, Queensland. BUR MINER RES GEOL GEOPHYS REP 144.Google Scholar
Davies, P. J. & Marshall, J. F. (in press). The Great Barrier Reef—evolution and growth. SPEC PUB INT ASSOC SEDIMENTOL.Google Scholar
Day, R. W., Whitaker, W. G., Murray, G. C., Wilson, I. H. & Grimes, K. G. 1983. Queensland geology. A companion guide to the 1:250,000 scale geological map (1975). GEOL SURV QUEENSLAND PUB 383.Google Scholar
Ellis, P. L. & Whitaker, W. G. 1976. Geology of the Bundaberg 1:250,000 sheet area. GEOL SURV QUEENSLAND REP 90.Google Scholar
Etheridge, M. A. & Lister, G. S. 1987. Extensional models for passive margin evolution. In Extended Abstracts—Applied Extension Tectonics, Bureau Mineral Resources Record 1987/51, 87–94.Google Scholar
Ewart, A. 1979. A review of the mineralogy and chemistry of Tertiary-Recent dacitic, rhyolitic, and related salic volcanic rocks. In Barker, F. (ed.) Trondhjemites, dacites and related rocks, 13–121. Amsterdam: Elsevier.CrossRefGoogle Scholar
Ewart, A. 1982. The mineralogy and petrology of Tertiary–Recent orogenic volcanic rocks: with special reference to andesiticbasaltic compositional range. In Thorpe, R. S. (ed.) Andesites, 25–95. New York: Wiley.Google Scholar
Ewart, A. & Chappell, B. W. 1989. Trace element geochemistry. In Johnson, R. W. (ed.) Intraplate volcanism in Eastern Australia and New Zealand, 219–35. Cambridge: Cambridge University Press.Google Scholar
Ewart, A., Chappell, B. W. & Menzies, M. A. 1988. An overview of the geochemical and isotopic characteristics of the Eastern Australian Cainozoic volcanic provinces. J PETROL SPEC LITHOSPHERE ISSUE, 225–73.Google Scholar
Falvey, D. A. & Middleton, M. F. 1981. Passive continental margins; evidence for a pre-breakup deep crustal metamorphic subsidence mechanism. Oceanol. Acta, Proc. 26th Intern. Geol. Congress, Geology of continental margins symposium, Paris, 7-17 July, 1980, 103–14.Google Scholar
Falvey, D. A. & Mutter, J. C. 1981. Regional plate tectonics and the evolution of Australia's passive continental margins. BMR J GEOL GEOPHYS 6, 1–29.Google Scholar
Frost, T. P. & Mahood, G. A. 1987. Field, chemical, and physical constraints on mafic-felsic magma interaction in the Lamarck Granodiorite, Sierra Nevada, California. GEOL SOC AM BULL 99, 272–91.Google Scholar
Green, D. C. & Webb, A. W. 1974. Geochronology of the northern part of the Tasman geosyncline. In Denmead, A. K., Tweedale, G. W. & Wilson, A. F. (eds), The Tasman Geosyncline—A symposium, 275–93. Brisbane: Geological Society of Australia, Queensland Division.Google Scholar
Henderson, R. A. 1980. Structural outline and summary geological history for northeastern Australia. In Henderson, R. A. & Stephenson, P. J. (eds) The geology and geophysics of northeastern Australia, 1–26. Brisbane: Geological Society of Australia, Queensland Division.Google Scholar
Hensel, H. D., McCulloch, M. T. & Chappell, B. W. 1985. The New England Batholith; constraints on its derivation from Nd and Sr isotopic studies of granitoids and country rocks. GEOCHIM COSMOCHIM ACTA 49, 369–84.Google Scholar
James, R. S. & Hamilton, D. L. 1969. Phase relation in the system NaAlSi308-CaAl2Si208 at 1 Kilobar water vapour pressure. CONTRIB MINERAL PETROL 21, 111–41.CrossRefGoogle Scholar
Jensen, A. R., Gregory, C. M. & Forbes, V. R. 1966. Geology of the Mackay 1:250,000 Sheet area, Queensland. BUR MINER RES GEOL GEOPHYS REP 104.Google Scholar
Kroenke, L. W. 1984. Cenozoic tectonic development of the Southwest Pacific. UN ESCAP, CCOP/SOPAC TECH BULL 6.Google Scholar
Maitre, R. W.Le (ed.) 1989. A classification of igneous rocks and glossary of terms. Recommendations of the International Union of Geological Sciences Subcommission on the systematics of igneous rocks. Oxford: Blackwell.Google Scholar
Lister, G. S., Etheridge, M. A. & Symonds, P. A. 1988. Extension history of the margins of the Tasman Sea. Abstracts, No. 21, Ninth Aust. Geol. Convention, February 1-5, 1988, Brisbane, 252–3.Google Scholar
Lister, G. S. & Etheridge, M. A. 1989. Detachment models for uplift and volcanism in the Eastern Highlands, and their application to the origin of passive margin mountains. In Johnson, R. W. (ed.) Intraplate Volcanism in Eastern Australia and New Zealand, 297–313. Cambridge: Cambridge University Press.Google Scholar
McDougall, I. & van der Lingen, G. J. 1974. Age of the rhyolites of the Lord Howe Rise and the evolution of the southwest Pacific Ocean. EARTH PLANET SCI LETT 21, 117–26.CrossRefGoogle Scholar
Nekvasil, H. 1988. Calculated effect of anorthite component on the crystallization paths of H2O-undersaturated haplogranitic melts. AM MINERAL 73, 966–82.Google Scholar
ODP Leg 135 Scientific Party 1991. A new view of arc/backarc systems. GEOTIMES 36(8), 19–20.Google Scholar
O'Reilly, S. Y., Griffin, W. L. & Stabel, A. 1988. Evolution of Phanerozoic Eastern Australian lithosphere: Isotopic evidence for magmatic and tectonic underplating. J PETROL SPEC LITHOSPHERE ISSUE, 89–108.Google Scholar
Paris, J.-P. 1981. Geologie de la Nouvelle-Calédonie. BUR RECHERCHES GEOL MIN 113.Google Scholar
Pearce, J. A. 1983. Role of the sub-continental lithosphere in magma genesis at active continental margins. In Hawkesworth, C. J. & Norry, M. J. (eds) Continental basalts and mantle xenoliths 230–49. Orpington: Shiva.Google Scholar
Shaw, S. E. & Flood, R. H. 1981. The New England Batholith, Eastern Australia: geochemical variations in space and time. J GEOPHYS RES 86, 10, 530–44.CrossRefGoogle Scholar
Smart, J. & Senior, B. R. 1980. Jurassic-Cretaceous basins of northeastern Australia. In Henderson, R. A. & Stephenson, P. J. (eds) The geology and geophysics of northeastern Australia, 315–28. Brisbane: Geological Society of Australian, Queensland Division.Google Scholar
Stephens, C. J. 1991. The Mungore Cauldron and Gayndah Centre. Late Triassic large-scale silicic volcanism in the New England Fold Belt near Gayndah, southeast Queensland. Unpublished Ph.D. Thesis, University of Queensland, Brisbane.Google Scholar
Sun, S.-S. & McDonough, W. F. 1989. Chemical and isotopic systematics of oceanic basalts. In Saunders, A. D. & Norry, M. J. (eds) Magmatism in the ocean basins, 313–45. GEOL SOC SPEC PUBL 42.CrossRefGoogle Scholar
Symonds, P. A., Fritsch, J. & Schluter, H.-U. 1984. Continental margin around the western Coral Sea Basin: Structural elements, seismic sequences, and petroleum geological aspects. In Watson, S. T. (ed.) Trans. Third Circum-Pacific Energy & Mineral Resources Conf, Hawaii, 243–52. Tulsa: American Association of Petroleum Geologists.Google Scholar
Symonds, P., Davies, P. J., Feary, D. A. & Pigram, C. J. 1988. Geology of the northeastern Australian margin basins. In PESA (Qld)—ODCAA SPE Petroleum Symp., Queensland 1988; Exploration Development: 61–77.Google Scholar
Symonds, P. A. & Willcox, J. B. 1989. Australia's petroleum potential in areas beyond an Exclusive Economic zone. BMR J AUST GEOL GEOPHYS 11, 11–36.Google Scholar
Veevers, J. J. (ed.) 1984. Phanerozoic earth history of Australia. Oxford: Clarendon Press.Google Scholar
Veevers, J. J., Powell, C. McA. & Roots, S. R. 1991. Review of seafloor spreading around Australia. I. Synthesis of the patterns of spreading. AUST J EARTH SCI 38, 373–89.CrossRefGoogle Scholar
Webb, A. W. & McDougall, I. 1968. The geochronology of the igneous rocks of Eastern Queensland. J GEOL SOC AUST 15, 313–46.CrossRefGoogle Scholar
Wood, D. A. 1980. The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province. EARTH PLANET SCI LETT 50, 11–30.CrossRefGoogle Scholar