The resource area of the Isaac Plains Complex (including Isaac Plains, Isaac Plains East, Isaac Downs and Isaac South) is in the northern part of the Bowen Basin in Central Queensland.
Isaac Plains Complex (IPC) lies within the Permo-Triassic Bowen Basin. The Bowen Basin consists of 10 kilometre (km) thick sequences of volcanic, shallow marine and terrestrial sediments and is categorised back-arc to foreland basin.
The general stratigraphy of IPC includes (oldest to youngest)
- Lower-Permian Reids Dome Beds;
- Lower-Upper Permian Back Creek Group;
- Upper Permian Blackwater Group, and Rewan group.
Coal seams occur within the Rangal Coal Measures which are Late Permian in age. These seams dip gently to the east at approximately 5 degrees.
The coal seams found within the Rangal Coal Measuresare the Leichhardt, Leichhardt Upper and Leichhardt Lower, and Vermont.
The seams have a cumulative thickness of approximately 7-10 m across the deposit.
The Vermont seam was not included in the resource estimate due to the lack of geological information. The results at hand indicate the coal to be of poorer quality.
Isaac Downs
Isaac Downs is located in the northern part of the Permo-Triassic Bowen Basin containing principally fluvial and some marine sediments. The economic seams are contained in the Late Permian Rangal Coal Measures which are approximately 100 m thick. The Rangal Coa ........