Sheared Margins of Western Australia, Phase 2In Development

Investment:

$69k (USD) per Sponsor

Status:

In Development

Principal Investigator(s):

Michal Nemčok
421-2-546 30 337 (Slovakia)
mnemcok@egi.utah.edu

John Conolly
61-4862-3311 (Australia)
john.conolly@bigpond.com

Value to Sponsors

  • The identification of pull-apart regions whose source rocks reached an oil window without adequate burial, but with the help of thermal transients controlled by transform fault-associated factors.
  • New thermal models to replace existing thermal models that were developed by tools originally designed for rifted margins.
  • Identify the regions where the source rock kitchens may have reached the hydrocarbon expulsion stage under the burial that would not be sufficient in the case of rifted margins.
  1. ArcGIS formatted databases and full documentation,
  2. Map of continental crust thickness distribution, set of maps on stratigraphic gaps associated with erosional unconformities spanning from the mid-Jurassic to Turonian unconformities,
  3. Set of maps on fault activity timing and type distribution; maps on magmatic rock lithology and emplacement timing distribution; map of pull-apart basin distribution,
  4. Two 3D finite-element models of thermal history in time for the Zeewyk-Houtman and Joey Wombat transform margins, and
  5. 1D source rock maturation models made for several clusters of pseudo-wells targeting distinct pull-apart areas located in the regions of calculated 3D models.

Oil discoveries such as the Jubilee Field located in the Equatorial Atlantic have encouraged exploration in sheared margins worldwide. Sheared margins have a thermal history, which is different from that of extensional margins. Recent studies by EGI in the Equatorial Atlantic and Indian sheared margins have indicated that a successful exploration program in this setting requires a detailed understanding of the thermal and structural history of continental break-up.

Objectives of this project are to refine the existing general timing of break-up for large margin segments with detailed break-up propagation timing, associated distinct vertical movement histories of different margin segments, and attempt to address associated depositional histories of individual margin segments.

EGI will undertake a robust analytical research program with both well samples and dredge samples and interpretation of existing data, focused on:

  1. Low-temperature thermochronology (constraining the exhumation histories of sedimentary provenances geared towards the first 10–40 Ma after break-up);
  2. Seismic interpretation aiming at sedimentary response to erosion in those exhumed areas;
  3. Well and seismic interpretation aiming at stratigraphic gaps associated with break-up unconformity;
  4. Magnetic and gravity anomaly interpretation aiming at ages of oldest oceanic crust; and
  5. Fluid inclusions (constraining migration timing and migration horizons).

This effort will be undertaken in context with a re-interpretation of existing open-file geological and geophysical data.