Abstract
I WISH to announce the presence in the Yilgarn Block1, Western Australia, of a major stratiform basic igneous complex with many features similar to the well documented Bushveldt2, Skaergaard3 and Stillwater layered4 intrusions. There is a stratiform basic sill 64 km south-east of Mount Magnet within the complexly deformed Archaean greenstones of the Yilgarn Block5. The sill, here provisionally designated the Challa Intrusion, crops out over an area in excess of 400 km2, with a discontinuous strike length of more than 200 km in a north-westerly direction from Challa through Barrambie to Yarrabubba, 30 km south of Meekatharra (Fig. 1). The separate occurrences of vanadium-rich titaniferous magnetites that outcrop along the whole of the sill from Youanmi in the south through Wymandoo, Windimurra, Challa, Windsor and Barrambie to Yarrabubba in the north, have not been recognized before as part of the one deposit. The sill consists of alternating layers of gabbros, anorthosites, pyroxenites and magnetite layers and lenses; the principal rock type is a medium to coarse grained gabbro with an average grain size of approximately 4 mm.
Similar content being viewed by others
References
Woodall, R., and Travis, G. A., WA Ninth Comm. Min. Congr. (1969).
Haughton, S. H. (ed.), The Geology of Some Ore Deposits of Southern Africa (1964).
Wager, L. R., and Deer, W. A., Meddelser øm Grönland, 105 (4) (1939).
Hess, H. H., Geol. Soc. Amer. Mem., 80, 230 (1960).
Prider, R. T., J. Roy. Soc. WA, 44, 1 (1960).
Prider, R. T., J. Roy. Soc. WA, 31, 43 (1945).
Korsch, R. J., (in the press, 1971).
Wager, L. R., and Brown, G. M., Layered Igneous Rocks (Oliver and Boyd, 1968).
Willemse, J., in The Geology of Some Ore Deposits of Southern Africa (edit. by Haughton, S. H.) (1964).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
HOCKLEY, J. Occurrence and Geological Significance of Layered Stratiform Intrusion in the Yilgarn Block, Western Australia. Nature 232, 252–253 (1971). https://doi.org/10.1038/232252a0
Received:
Issue Date:
DOI: https://doi.org/10.1038/232252a0
- Springer Nature Limited