Abstract
A new age determination has been made on the Greenstones of the Agnew-Jones Creek Area, Western Australia by use of the Zircon U-Pb dating procedure. Late stage granophyre from the differentiated Kathleen Valley doleritic sill provided zircons which are otherwise unobtainable from mafic rock suites. An upper intercept age of 2,795 + 38 Ma, extends the known length of the otherwise tightly established, late Archaean tectonic cycle at Agnew from 250 Ma to 320 Ma. A lower intercept of age 1,345 ± 153 Ma is interpreted to record either a hitherto unknown very low temperature heating, or a hitherto unknown tectonic, uplift and cover removal, in the mid-Proterozoic. The existance of a postulated ancient unconformity of craton size dimensions may be being confirmed and dated. Apart from some inconclusive olivine and pyroxene Rb-Sr isotopic data from 190km to the west, the only evidence known that could support either possibility is found outside the Yilgarn Block itself. Minor perturbations to a simple two-stage discordia pattern imply further small amounts of lead loss at later times. Studies of this nature could eventually provide information on the later history of stabilized cratons.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Ahmat AL, de Laeter JR (1982) Rb-Sr isotopic evidence for Archean-Proterozoic crustal evolution of part of the central Yilgarn Block, Western Australia: constraints on the age and source of the Windimurra Gabbroid. J Geol Soc Aust 29:177–190
Arriens PA (1971) The Archaean geochronology of Australia. Geol Soc Aust Spec Publ 3:11–23
Arriens PA, Lambert IB (1976) On the age and strontium isotopic geochemistry of granulite facies rocks from the Fraser Range, Western Australia and the Musgrave Ranges, Central Australia. Geol Soc Aust Spec Publ 2:377–388
Bunting JA, de Laeter JR, Libby WG (1975) West Aust Geol Surv Ann Rp for 1974:117–126
Cooper JA, Nesbitt RW, Platt JP, Mortimer GE (1978) Crustal development in the Agnew region, Western Australia, as shown by Rb/Sr isotopic and geochemical studies. Precamb Res 7:31–59
Daniels JL (1975) Palaeogeographic development of Western Australia. In the Geology of Western Australia, Geol Surv of West Aust Mem 2:437–445
de Laeter JL (1976) Rb-Sr whole rock and mineral ages from the Gasgoyne Province. West Aust Geol Surv Ann Rp for 1975:126–130
Doepel JJG (1975) Albany-Fraser Province. Geol Surv of West Aust Mem 2:94–101
Durney DW (1972) A major unconformity in the Archaean, Jones Creek, Western Australia. J Geol Soc Aust 19:251–259
Gebauer D, Grunenfelder M (1976) U-Pb zircon and Rb-Sr whole rock dating of low grade metasediments. Example: Montagne Noire (Southern France). Contrib Mineral Petrol 59:13–32
Gee RD, Baxter JL, Wilde SA, Williams IR (1981) Crustal development in the Archaean Yilgarn Block, Western Australia. In: Archaean Geology. Spec Publ Geol Soc Aust 7:57–69
Goldich SS, Hedge CE, Stern TW (1970) Age of the Morton and Montevideo Gneisses and related rocks, Southern Minnesota. Bull Geol Soc Am 81:3671–3696
Goldich SS, Mudrey JR (1972) Dilatancy model for discordant U-Pb zircon ages. In: Recent Contributions to Geochemistry and Analytical Chemistry, Tugaranov, A.I. (ed). Wiley, New York, 415–418
Krogh TE (1973) A low contamination method for the hydrothermal decomposition of zircon and extraction of U and Pb for isotopic age determinations. Geochim Cosmochim Acta 37:485–494
Ludwig KR (1980) Calculation of uncertainties of U-Pb isotopic data. Earth Plan Sci Let 46:212–220
Marston RJ, Travers GR (1976) Stratigraphic implications of heterogenous deformation in the Jones Creek Conglomerate (Archaean), Kathleen Valley, Western Australia. J Geol Soc Aust 23:141–156
McCulloch MT, Compston W (1981) Sm-Nd age of Kambalda and Kanowna greenstones and heterogeneity in the Archaean mantle. Nature 294:322–327
McIntyre GR, Brooks CR, Compston W, Turek A (1966) The statistical assessment of Rb/Sr isochrons. J Geophys Res 71:5459–5468
Nieuwland DA, Compston W (1981) Crustal evolution in the Yilgarn Block near Perth, Western Australia. In: Archaean Geology. Geol Soc Aust Spec Publ 7:159–172
Peterman ZE, Zartman RE, Sims PK (1980) Tonalitic Gneisses of early Archaean Age from northern Michigan. Geol Soc Am Spec Pap 182:125–134
Pidgeon RT (1978) 3450 m.y. old volcanics in the Archaean layered greenstone succession of the Pilbara Block, Western Australia. Earth Plan Sci Let 37:421–428
Platt JP, Rutland RWR, Allchurch PD (1978) Archaean tectonics in the Agnew supracrustal belt, Western Australia. Precamb Res 7:3–30
Playford PE, Cope RN, Cockbain AE, Low GH, Lowry DC (1975) Phanerozoic. In: The Geology of Western Australia. Geol Surv West Aust Mem 2:223–436
Roddick JC, Compston W, Durney DW (1976) The radiometric age of the Mt. Keith Grandiorite, a maximum age estimate for an Archaean greenstone sequence in the Yilgarn Block, Western Australia. Precamb Res 3:55–78
Silver LT, Deutsch S (1963) Uranium lead variations in zircon: a case study. J Geol 71:747–758
Stern TW, Goldich SS, Newell MF (1966) Effects of weathering on the U-Pb ages of zircons from the Morton Gneiss, Minnesota. Earth Plan Sci Let 1:369–371
Shestakov GI (1972) Diffusion of lead in monazite zircon sphene and apatite. Trans Geochimiya 10:1197–1202
Tilton GR (1960) Volume diffusion as a mechanism for discordant lead ages. J Geophys Res 65:2933–2945
Turek A (1966) Rubidium Strontium studies in the Kalgoorlie Norseman Area, Western Australia. Ph D thesis ANU (unpubl)
Wasserburg GJ (1963) Diffusional processes in lead-uranium systems. J Geophys Res 68:4823–4846
Wetherill GS (1956) Discordant uranium-lead ages I. Trans Am Geophys Un 37:320–326
Williams JS, Elias M, de Laeter JR (1978) Geochronology and evolution of the Eastern Gascoyne Province and the adjacent Yilgarn Block. Geol Surv of West Aust An Rp for 1977:50–56
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cooper, J.A., Dong, Y.B. Zircon age data from a Greenstone of the archaean Yilgarn Block, Australia: Mid proterozoic heating or uplift?. Contrib Mineral Petrol 82, 397–402 (1983). https://doi.org/10.1007/BF00399716
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00399716