Serpentine Hill Quarry
Location: 6.5km north of Zeehan along the Murchison Highway (towards Rosebery) | Google Maps Reference
Key facts about this geosite:
• Mining of Asbestos from ultramafic rocks at Serpentine Hill and “Argent Tunnel Prospect” occurred during the early 1940’s
• The rare purple mineral stichtite is found here
• The serpentine bearing complexes are a series of thrust-emplaced, dismembered ophiolitic bodies
Geosite description: This site, is a good exposure of Early Cambrian ultramafic rocks, remnants of thrust-emplaced, dismembered ophiolitic sequences. They were originally mostly peridotites and pyroxenites, rich in olivine and enstatite, but are now largely altered to serpentinite.
Asbestos was mined from these ultramafic rocks in workings at Serpentine Hill across the road and the nearby “Argent Tunnel Prospect” during the early 1940’s. By the end of October 1945 approximately 360 tonnes of bagged fibre had been extracted. Sparse asbestos veins and fragments still occur in this area and visitors should be careful not to break up any potentially asbestos bearing rocks, as the fibres are potentially carcinogenic if inhaled in large quantity.
At the Tunnel Hill quarry west of the highway, the rare purple to lilac mineral stichtite was found in an unusually rich vein-like deposit. This is a popular mineral for lapidarists and mineral collectors, and polishes well. The main lode has been worked out, but small specimens can still be found by diligent collectors.