The structure and shape of the Jimberlana Intrusion, Western Australia, as indicated by an investigation of the Bronzite Complex

• Published in: Geological Magazine
• Main Authors: McClay, K. R., Campbell, I. H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1976
• Subjects: Geology; muskox
• Online Access: http://dx.doi.org/10.1017/s0016756800036426; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800036426

Summary The structure of the partly exposed lower section of the Jimberlana Intrusion has been determined by combining the geophysical evidence with the available geological and diamond drill hole data. The results have been added to the wellknown upper section to show that Jimberlana is not a dyke-like body as had previously been thought, but is a horizontal pipe-like intrusion 180 km long, 2.5km wide and 5.5 km deep, with a V-shaped cross-section. A marginal series with ‘reversed’ fractionation and high primary dips, similar to the marginal series of the Muskox Intrusion, occupies the lower part of the intrusion. The rocks of this series display rhythmic layering and a variety of cumulate textural types indicating that cumulate processes can take place during deposition on near-vertical dipping surfaces.