g. Mozley and Goodwin, 1995 and Garven et al., 1999), leakage of contaminated groundwater (e.g. Mal’kovskii and Pek, 2001) or oil migration (e.g. Moretti, 1998). In addition, examples of faults acting as both conduits and barriers are documented (e.g. Bense and Person, 2006). Where aquifers thin or abut against basement highs, this can also induce upwelling of groundwater and result in the formation of wetlands or springs at the surface (Raiber et al., PLX3397 2009). The permeability of rocks can remain unchanged, or be enhanced adjacent to faults within an aquifer, and may decrease perpendicular to faults (Ferrill et al., 2004). Flow barriers

can, for example, result where units of contrasting hydraulic properties (e.g. aquifers

vs. aquitards) are juxtaposed along faults. Where the impact of CSG exploitation on regional groundwater flow dynamics is investigated, it is very important to assess whether aquitards form good regional seals, or whether these seals are compromised by local fracturing or along regional fault systems. Therefore, it is important to understand how faults influence the geometry of aquifer/aquitards and coal seam sequences. In the Galilee/Eromanga basins, regional faults have been previously identified from seismic data, with vertical displacements recorded for sedimentary sequences in both basins. However, while displacement along some faults has been studied in the past (e.g. Cork Fault, Fig. 2; Hawkins and Harrison, 1978 and Ransley

and Smerdon, 2012), the overall regional understanding Thiazovivin solubility dmso of the influence of faults on aquifer geometry in these basins is at present limited. Further, it is poorly understood whether the faults in the Galilee/Eromanga basins behave as conduits or as barriers for groundwater flow and how permeability may change across the faults. In this current study, we aim to develop a 3D geological model to examine characteristics of faulting on aquifers and aquitards in learn more the north-central Galilee and Eromanga basins using well log data, seismic surfaces, surface geology and surface elevation data. For this purpose, the main geological structures in the area are mapped in detail from seismic surfaces, and an assessment is made on how they influence the geometric relationships of the major aquifers and aquitards, and how they are spatially related to surface hydrological features. The development of this 3D geological model is the first step of a comprehensive study that aims to understand any potential aquifer/aquitard connectivity pathways between the Galilee and Eromanga basins. The Galilee Basin is a Late Carboniferous to Middle Triassic sedimentary basin, located in central Queensland. It extends over approximately 247,000 km2 and consists of two main lobes which are separated in the southwest by the Maneroo Platform (Fig. 1). In the central Galilee Basin (Fig.