The Cloncurry Lineament: Geophysical and geological evidence for a deep crustal structure in the Eastern Succession of the Mount Isa Inlier

J. R. Austin*, T. G. Blenkinsop

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Citations (Scopus)

Abstract

The Cloncurry Lineament is a major feature evident from wavelet processed magnetic and gravity potential field data over the Mount Isa Inlier Eastern Succession. It is laterally continuous over 200 km of strike length and is inferred from the gravity data to extend to at least 30 km depth. It delineates the contact between two major Paleoproterozoic sedimentary sequences, and is spatially associated with a number of mineral deposits including Cannington Ag-Pb-Zn, Ernest Henry Cu-Au and many smaller Cu ± Au deposits. Mapping and magnetic forward modelling along several profiles perpendicular to the Cloncurry Lineament suggests that it corresponds to the eastern margin of a 5-10 km wide deformation zone within the calc-silicate dominated Doherty Formation. The western boundary of this deformation zone is a distinct narrow fault zone (the Cloncurry Fault). The deformation zone consists of multiple generations of shearing and faulting accompanied by metasomatic alteration. Large variations in the magnetic response within the deformation zone can be modelled as sub-vertical brecciation zones. Breccia types range from highly magnetic actinolite-albite-magnetite breccias through to late stage, non-magnetic, quartz-K-feldspar ± hematite breccias. The long-lived history of multiple reactivation, strike continuity, width and vertical extent of the deformation zone suggest that it is a major crustal structure. The structure may have originated during basin formation and later acted as a fluid pathway for alteration and base metal mineralization.

Original languageEnglish
Pages (from-to)50-68
Number of pages19
JournalPrecambrian Research
Volume163
Issue number1-2
DOIs
Publication statusPublished - 20 May 2008
Externally publishedYes

Keywords

  • Cloncurry Lineament
  • Doherty Formation
  • Magnetic forward modelling
  • Mount Isa Inlier
  • Potential field worms
  • Soldiers Cap Group

Fingerprint

Dive into the research topics of 'The Cloncurry Lineament: Geophysical and geological evidence for a deep crustal structure in the Eastern Succession of the Mount Isa Inlier'. Together they form a unique fingerprint.

Cite this