Jumbulyer Goldfield, Mount Magnet, Mount Magnet Shire, Western Australia, Australiai

Regional Level Types
Jumbulyer Goldfield	Ore Field
Mount Magnet	Mountain
Mount Magnet Shire	Shire
Western Australia	State
Australia	Country

Named after a nearby hill. This is a small historic goldfield, approximately 20 kilometres south-west of Mount Magnet. It can be accessed via an un-marked gravel road heading south from the Yalgoo-Mount Magnet Road, approximately 1 kilometres east of the Yowergabbie Station turn-off. The area contains several active leases from part-time prospectors. Please remember metal detecting is only allowed with the lease holders permission, and visitors should avoid leaving the road and interfering with their camps.

Most of the locations, are within an area north of the Yoweragabbie homestead, covering an area about 5 kilometres east-west, and the same distance north-south, in turn south of the Mount Magnet-Yalgoo Road.

The field has always been the preserve of lone prospectors, and individual miners, and with one exception has not seen modern mining. The exception is the Hillcrest Mine in the far north-east of the area, where a small abandoned open pit is found.

There are over 90 small historic gold workings from the 1890's on this goldfield, an area of about 5 square kilometres. It highlights the difficulty facing Mindat in listing gold mines for Western Australia. Often the names for these sites have long been forgotten, the shafts has collapsed, little information or details officially of tonnages, and virtually impossible to locate a specific site on the ground with mine workings next to each other for miles.

An intensive metal detecting exercise by a mining company found over 3000 gold nuggets around 1986, in the south-west portion of the goldfield. The largest was 5 oz.

The main period of activity was from the late 1930's to early 1940's, but even then only production figures was found as information.

The area first appears in the Department of Mines reports in 1937, listed simply as Jumbulyer, with 205.50 tonnes of ore at 192 oz. The following years until 1948 the area is reported for gold production. Pantomine, Big Head, Gold Bug, and the Granites mines all make an appearance, with small tonnages. Usually the biggest tonnage entry is 'sundry', indicating several further small operations, but production amounts did not warrant a separate entry. The fact these places were active over the war years, may indicate old time prospectors were active on the field, not needed for the war effort. However this is pure conjecture from the writer. The field was most active in 1942, listing four mines and sundry, but still only about 150 tonnes of ore was crushed. By 1948 only one mine is listed at 136 tonnes.

In the south-west portion of the goldfield, directly north of the Yoweragabbie Homestead, gold is found in narrow quartz veins within kaolinised felsic rocks. The felsic rocks may also host gold. There are two dominant sets of quartz veins, one bluish striking north-south and dipping west. The second is greyish quartz striking east-west.

Mineralisation is found in a major shear zone with fault intersections, in granitoid and felsic porphyry intrusives, and quartz veining. Gold is found commonly along mafic/felsic contact zones, especially the southern margin of the Jumbulyer Granite, with quartz veins and stockworks. Further the BIF as part of the Jumbulyer Ridge hosts anomalous gold at 0.2 to 0.5 g/t.

Further west and south of the Hillcrest Mine, many of the historic workings are found along the major north-south trending Britannia Well Shear. Gold is found at the contact of granitoid intrusives and the Boorgardie Formation BIF/cherts.

Several sheds and small old gold processing plants across the field may indicate it subsequently received attention from individual miners on a part time basis. The area has been explored by companies since the 1980's.At present (2015) the area is under active lease by Mount Magnet South NL, who is drilling various prospects on the field.

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