Skip to main content
padlock icon - secure page this page is secure

Late Neoproterozoic to Holocene thermal history of the Precambrian Georgetown Inlier, northeast Australia

Buy Article:

$60.00 + tax (Refund Policy)

Carboniferous‐Permian volcanic complexes and isolated patches of Upper Jurassic — Lower Cretaceous sedimentary units provide a means to qualitatively assess the exhumation history of the Georgetown Inlier since ca 350 Ma. However, it is difficult to quantify its exhumation and tectonic history for earlier times. Thermochronological methods provide a means for assessing this problem. Biotite and alkali feldspar 40 Ar/ 39 Ar and apatite fission track data from the inlier record a protracted and non‐linear cooling history since ca 750 Ma. 40 Ar/ 39 Ar ages vary from 380 to 735 Ma, apatite fission track ages vary between 132 and 258 Ma and mean track lengths vary between 10.89 and 13.11 μm. These results record up to four periods of localised accelerated cooling within the temperature range of ∼320–60°C and up to ∼14 km of crustal exhumation in parts of the inlier since the Neoproterozoic, depending on how the geotherm varied with time. Accelerated cooling and exhumation rates (0.19–0.05 km/10 6 years) are observed to have occurred during the Devonian, late Carboniferous‐Permian and mid‐Cretaceous — Holocene periods. A more poorly defined Neoproterozoic cooling event was possibly a response to the separation of Laurentia and Gondwana. The inlier may also have been reactivated in response to Delamerian‐age orogenesis. The Late Palaeozoic events were associated with tectonic accretion of terranes east of the Proterozoic basement. Post mid‐Cretaceous exhumation may be a far‐field response to extensional tectonism at the southern and eastern margins of the Australian plate. The spatial variation in data from the present‐day erosion surface suggests small‐scale fault‐bounded blocks experienced variable cooling histories. This is attributed to vertical displacement of up to ∼2 km on faults, including sections of the Delaney Fault, during Late Palaeozoic and mid‐Cretaceous times.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Keywords: Georgetown Inlier; argon‐argon analysis; fission‐track analysis; thermochronology

Document Type: Research Article

Affiliations: 1: Geologisches Institut, ETH Zentrum, Zürich, CH-8092, Switzerland 2: Australian Geodynamics Cooperative Research Centre, VIEPS, School of Earth Sciences, University of Melbourne, Vic. 3010, Australia

Publication date: February 1, 2001

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more