Fracture formation in heterogeneous sediments, Catherine Hill, Sydney Basin, NSW
This project involves mapping and quantifying fracture patterns at Catherine Hill Bay, New South Wales.
Understanding the role of fluid flow through the Earth’s subsurface has been a long standing geological challenge.
Understanding of this process is critical to our ability to predict the distribution of hydrothermal mineral deposits; fluid migration within water aquifers, CO2 and waste storage sites; and within hydrocarbon reservoirs in sedimentary basins.
Fractures and faults can provide interconnected, hydraulically conductive networks that enable large-volume fluid transport in the Earth’s crust, a concept known as structural permeability.
A fracture is considered hydraulically conductive when it is critically stressed, as it is optimally oriented to the present-day stress field. However, the ability for a fracture to be critically stressed is also controlled by the rock properties (lithology, rock strength, Poisson’s ratio, Young’s Modulus) and pore pressure.
In this project we will endeavour to rigorously map and quantify the fracture patterns at Catherine Hill Bay, NSW, to demonstrate the control of lithology on fracture formation and development, and ultimately fluid flow associated with these fractures.
Catherine Hill Bay is located 36km south of Newcastle in NSW. Here, Permian-Triassic sediments of the northern most part of the Sydney Basin crop out. Several fracture sets are observed in outcrop; some are isolated only within the Great Northern Coal Seam, while others pass through the entire sequence of rocks both above and below the coal seam, and in some cases these through-going fractures are refracted by the differing lithologies.
This complex fracture system details the interplay between fracture formation and development with lithology, as well as describing the tectonic evolution of the northern Sydney Basin and providing an analogue for coal seam gas production in other regions (e.g. the Cooper Basin, South Australia).
- It would be useful if you have completed Structural Geology II, Tectonics III and Field Geoscience Program III.