Latitude & Longitude (WGS84):	16° 37' 30'' South , 128° 15' 41'' East
Latitude & Longitude (decimal):	-16.62501,128.26143
GeoHash:	G#: qv51qtt07
Locality type:	Mine
Köppen climate type:	BSh : Hot semi-arid (steppe) climate

Pompey's Pillar is an impressive natural rock spire a short distance east of the Great Northern Highway, approximately 165 kilometres south of Kununurra.

Four miles east of the pillar is siliceous hematite outcropping for 10 miles along the crest of a mountain range. There are two deposits, being Pompey's Pillar, divided into a west and east zone, and secondly Matsu to the south-east.

Both are near the base of the Golden Gate Siltstone. The Ivanhoe Fault has displaced the Matsu deposit several kilometres east from the Pompey deposit. Matsu is larger but lower grade, and is more difficult to access.

The Pompey's Pillar deposit forms the cap of a range, the deposit 35 feet thick, of massive sandy hematite beds, and hematite sandstone, interbedded with Fe shale and quartz sandstone. There is some pisolith and botryoidal goethite in the weathered surface.

The Pompey's Pillar deposit was first drilled in 1962, estimated at 60% Fe with selective mining. The deposit is 9000 feet long, 400 feet wide, and 15 to 35 feet thick. The eastern section of the deposit is much smaller.

Matsu caps a gentle slope, several hundred metres wide, striking for 4 miles at 35 feet thick. Impurities like sandstone and shale probably make the average Fe around 50% or less.

The low grade, limited extent of the deposits, and huge deposits of iron ore elsewhere in Western Australia, would indicate mining would never take off here, but high iron ore prices changed that. KMG commenced mining iron ore at Pompey's Pillar, which it re-named Ridges, in July 2011, shipping ore out of Wyndham. The mine was placed on care and maintenance in February 2015, after the high grade reserves were exhausted, and conveniently iron ore prices had crashed. Matsu remains undeveloped at the time of writing.

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

Mineral List

2 valid minerals.

Rock Types Recorded

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

Late Devonian - Middle Devonian 358.9 - 393.3 Ma ID: 3188660	Paleozoic sedimentary rocks Age: Devonian (358.9 - 393.3 Ma) Comments: Bonaparte Basin Lithology: Limestone,sandstone,siltstone,conglomerate Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]
Mesoproterozoic 1000 - 1600 Ma ID: 813570	Hensman Sandstone Age: Mesoproterozoic (1000 - 1600 Ma) Stratigraphic Name: Hensman Sandstone Description: Massive, silicified white quartz sandstone Comments: sedimentary siliciclastic; synthesis of multiple published descriptions Lithology: Sedimentary siliciclastic Reference: Raymond, O.L., Liu, S., Gallagher, R., Zhang, W., Highet, L.M. Surface Geology of Australia 1:1 million scale dataset 2012 edition. Commonwealth of Australia (Geoscience Australia). [5]
Stenian - Ectasian 1000 - 1400 Ma ID: 2326786	Golden Gate Siltstone Age: Mesoproterozoic (1000 - 1400 Ma) Stratigraphic Name: Golden Gate Siltstone Lithology: Black pyritic shale, micaceous siltstone, fine-grained sandstone, subgreywacke, red mudstone, green shale, tuff, sandy hematite Reference: Plumb, K.A. Geology of the Lissadell. Commonwealth of Australia (Geoscience Australia). [45]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License

References

External Links