Stanmore Resources Limited is a 59% indirect subsidiary of Golden Energy and Resources Limited, and owns the Eagle Downs Project.
On 12 August 2024, Stanmore Resources completed the acquisition of South 32’s 50% interest in the Eagle Downs JV Project, as well as 100% of Eagle Downs Coal Management Pty Ltd. Subsequently, the Group announced that it had completed the acquisition of the remaining 50% interest in the Eagle Downs JV Project and 100% interest in the Eagle Downs South tenements from Aquila, resulting in the Stanmore Resources owning 100% of both projects.
Summary:
The Eagle Downs Coal Resource is located in the northern part of the Permo-Triassic Bowen Basin containing principally fluvial and some marine sediments. The known economic seams are contained in the Late Permian Moranbah Coal Measures (MCM) which is approximately 300m thick. The Moranbah Coal Measures are overlain by the Fort Cooper Coal Measures, Rangal Coal Measures (RCM) and the Late Permian to Early Triassic Rewan Group.
Weathering
Depth of weathering over the Eagle Downs area ranges from 15 to 30m averaging 17m. As the seam subcrop zone falls well to the west of the project area for all seams, weathering impacts on coal freshness is not a consideration for this project. Weathering will potentially impact the means of access (shaft or decline) to the potential underground Coal Resources. Quaternary sediments and or soil are relatively thin in the Eagle Downs Project area. They range in thickness from Oto 15m averaging approximately 1 m.
Coal Seams
General
The Q, HCU, HCL and DY Seams of the Moranbah Coal Measures form the principal economic coal resources in the Eagle Downs resource area. In the south of the Eagle Downs Project area the HCU and HCL seams coalesce to form a thickened pod of coal named the Harrow Creek seam.
QSeam
The Q Seam is typically 1.8m to 2. 7m thick (average 2.3m). Q seam is quite consistent across the Eagle Downs area but splits to the south east of the deposit area. The seam is relatively free of non coal bands; although there are some thin stone bands at the top of the seam. For this assessment the Q Seam has been treated as potentially one mining interval, i.e. there are no sub plies. At the shallowest point the Q seam is 160m below the surface, while at depth it is up to 400m below surface. The Q seam whole seam raw ash averages 28% and has a high vitrinite content.
Harrow Creek Upper Seam
The Harrow Creek Upper seam (HCU) averages 4.0m in thickness in the Eagle Downs area. South of the coalesced Harrow Creek seam, the HCU is slightly thicker than in the Eagle Downs area.
The HCU seam has five plies, three of which (HCU1,2,3) are persistent over the deposit. The thin top ply (HCU 1) being quite high in ash due to the presence of a series of thin stone bands and generally duller coal. Plies HCU2 and HCU3 have moderate ash. In the northern portion of the resource area the HCU thickens and this corresponds to the development of basal plies HCU4 and HCUS. HCU4 is thin, stoney and high in ash. HCUS is thin but has moderate ash.
The target working section for longwall mining is the HCU25 section which is inclusive of the HCU23 section. The HCU1 is only likely to be mined where the HCU25 is less than the planned longwall cutting height of 4.2m. The HCU seam whole seam raw ash averages 21%.
Harrow Creek Lower Seam
The Harrow Creek Lower seam (HCL) averages 8.1 m in thickness in the Eagle Downs area. There are 4 plies (HCL 1 to HCL4) persistent over the deposit. The HCL 1 is a higher ash section in the main body of the deposit however south of the Harrow Creek seams coalescence zone the HCL 1 quality significantly improves. In the Eagle Downs Project area, the shallowest HCL coal is approximately 300m below surface. At depth the cover of the HCL seam is up to 600m thick. Mid-burden between the HCU and HCL seam varies from about 50m in the middle of the area, thins to the north, and eventually coalesces together (quite rapidly) over a small area in the south. The HCL seam whole seam raw ash averages 33%, due to the high number of stone bands. Selective mining of supplies may achieve better ash levels. From Clean Coal Composite data, coking coal products of acceptable ash levels can be achieved, however, the yield is lower than for the HCU (due to the high non coal volumes in the seam).
Dysart Seam
The Dysart seam (DY) averages 5.1 m in thickness in the Eagle Downs area. Within the main DY seam there are up to four plies with the top one (D4) not always present (or resent as a carbonaceous unit). The basal 3 lies are the most consistent, with plies 1 and 3 being relatively clean coal units up to 1.6m in individual thickness. Plys 1 and 3 are separated by a non coal unit Ply 2 up to 40cm in thickness. Ply 4 varies widely across the area, and has varying ash levels (generally high). The thickness of the D1 to D3 plies of the DY averages 4.4m, The depth of cover of the DY seam ranges from 400m to 800m. Mid-burden between the HCL and DY seams is relatively consistent varying from about 66m to 72m. The Dysart seam whole seam raw ash averages 32%, due in part to the thick non coal plys.
Structure
In the Eagle Downs Project area, the Moranbah Coal Measures dip to the east at 3 to 8 degrees. The dip steepens in the northern part of the area where the strike changes to a northwest orientation. The structure of the area is well defined by 500m spaced drilling complementing 3D and 2D seismic surveys. The principal features of the area is a graben structure in the north and a broad anticlinal form. The graben is aligned east west and is approximately 330m wide. The graben is downthrown approximately 30m in the west with the down throw diminishing to the east. The southern fault branch of the graben diminishes towards the east to a point where it cannot be distinguished.
Results of the 3D seismic survey confirm known large modelled faults and indicate no "show stoppers" over the majority of the target area. The 3D seismic dataset provides significant additional confidence in the structure of the target area. The 3D seismic data has been used to generate the seam structure models for the HCU, HCL and DY seams.
Coal Quality
The Q, HCU, HCL and DY seam coals in the Eagle Downs resource area may be classified as medium to low-medium volatile bituminous metalliferous coal with a reflectance ranging from 1.30 to 1.95%. All the target seams can deliver a coking or PCI/thermal product. The Q seam is closer to 1.35% reflectance. The HCU seam has lower ash levels than the other seams and has reasonable washability characteristics.
The Q seam has a higher inherent raw ash level but because of high vitrinite content produces a reasonable coking coal product at a lower yield. A secondary product can be produced from the Q seam, which increases the total yield. The HCL and DY seams are higher in ash and have fair washability characteristics albeit at lower yields. Raw and washed coal total sulphur is moderate to low and Phosphorus levels are moderate. The raw Inherent moisture is in the order of 1.7%.