New South Wales
Under New South Wales
Explorers in New South Wales have to report their drilling to the State, and once a report is no longer confidential the Geological Survey of NSW adds its holes to a public database. Its mineral subset, with the best assays the survey has pulled from company data files, is open for anyone to use.
That gives {holes} mineral drill holes you can see here. Almost all of them were drilled by earlier explorers, often decades ago and by companies that no longer exist. This tour flies you through the places and stories behind them, then hands you the controls.
1960 to today
Sixty years of looking
Watch the holes arrive year by year, by the year each hole was drilled (or reported, where the drill date is missing). The 1960s bring the first big programmes, then the numbers peak: {d1970} holes in the 1970s and {d1980} in the 1980s, when shallow auger and RAB holes were drilled by the thousand to test soil and rock chemistry.
There are {d1990} holes from the 1990s, {d2000} from the 2000s and {d2010} from the 2010s. The 2020s look quiet ({d2020} so far) because recent drilling is mostly still confidential. Another {d0} holes have no usable date, so they only show when the year filter is open.
1883
Broken Hill
In September 1883 Charles Rasp, a boundary rider on Mount Gipps station, pegged a claim on a broken ridge, thinking it held tin. It held one of the richest silver, lead and zinc lodes ever found. The syndicate he joined floated the Broken Hill Proprietary Company in 1885, the start of BHP.
Mining along the line of lode has gone on ever since. The open-file holes here are coloured by lead. {site}
Copper and zinc
The Cobar Basin
Colour the holes by copper and the Cobar Basin stands out in the centre-west of the State. {Cu} of the open-file holes were assayed for copper. Each column's height is the number of holes in it, and its colour is a high but typical grade there (9 in 10 of its holes are below it), so one lucky hole does not paint a whole district.
The cluster around Cobar holds the CSA, Peak and Elura mines; further east are Tritton and Tottenham, and to the south Hera and Nymagee.
1871
Cobar and the CSA mine
Copper was found at Cobar in 1870, and the Great Cobar mine became one of the biggest copper producers in Australia by the early 1900s. The CSA mine, a few kilometres north of the town, takes its name from the Cornish, Scottish and Australian company that worked it from the 1870s.
CSA is still a deep underground copper mine. The holes around it are coloured by copper. {site}
1974
Elura: found from the air
Elura lies under flat red plains north-west of Cobar, with almost nothing to see at the surface. The Electrolytic Zinc Company found it in 1974 by drilling an airborne magnetic anomaly, and it has been mined for zinc, lead and silver since 1983, now as the Endeavor mine.
Most of the open-file holes here are Electrolytic Zinc's. They are coloured by zinc. {site}
Gold at Cobar
Peak and New Cobar
South of the town the same belt of rocks carries gold as well as copper. The Peak and New Cobar deposits were worked in the early days and again from the 1990s by Peak Gold Mines.
The holes here are coloured by gold. {site}
Gold and copper
The Lachlan Fold Belt
Switch to gold and the middle of the State lights up from Orange to West Wyalong. These are the rocks of the Lachlan Fold Belt, old volcanic arcs that hold porphyry copper-gold deposits such as Cadia, Northparkes and Cowal, as well as the reef and alluvial gold of the first rushes.
{Au} of the open-file holes were assayed for gold. The columns show where they cluster and how rich a typical hole there is.
1851
Ophir, Hill End and the first gold rush
In February 1851 Edward Hargraves, with John Lister and the Tom brothers, washed gold from Lewis Ponds and Summer Hill creeks north of Orange. The field was named Ophir, and by May the first Australian gold rush was under way. Bathurst, Sofala and Hill End soon followed.
Hill End boomed again in 1872 when the Holtermann nugget, a slab of reef gold weighing about 286 kilograms, came out of the Star of Hope mine. Only a few modern holes have been drilled here. {site}
1992
Cadia-Ridgeway
Copper was mined at Cadia, south of Orange, in the 1860s and iron ore early in the twentieth century. In 1992 Newcrest Mining found the large low-grade Cadia Hill gold-copper deposit here, then Ridgeway and Cadia East. Cadia became one of the biggest gold mines in Australia.
The open-file holes come from many earlier explorers in the district. They are coloured by gold. {site}
1976
Northparkes
North of Parkes, Geopeko drilled through soil cover in the 1970s and found a cluster of porphyry copper-gold bodies. The Northparkes mine opened in the 1990s and mines the ore by block caving, letting it collapse into tunnels underneath.
Most of the open-file holes here are Geopeko's. They are coloured by copper. {site}
1981
Lake Cowal
Gold under a lake: Geopeko found the Cowal deposit beneath Lake Cowal, near West Wyalong, in the early 1980s. Years of environmental studies followed, and the open pit, built behind a bund wall in the lake, has produced gold since 2006.
The holes here are coloured by gold. {site}
1970
Woodlawn
Near Tarago, between Goulburn and Canberra, soil sampling by Jododex led to the discovery of the Woodlawn zinc, copper and lead deposit around 1970. It was mined from 1978 to 1998, and has since been reopened underground.
The holes here are coloured by zinc. {site}
Tin
Ardlethan tin field
Tin was found at Ardlethan, north-west of Wagga Wagga, early in the twentieth century. It was mined from a breccia pipe by open cut for decades until the mid-1980s, when the world tin price collapsed.
The holes here are coloured by tin. {site}
Antimony
Hillgrove
In the gorges east of Armidale, Hillgrove has been mined on and off since the 1870s for antimony and gold, with some tungsten. Antimony is now on Australia's list of critical minerals.
The holes here are coloured by antimony. {site}
Your turn
How to read this map
Each point is one open-file hole, coloured by the best assay the Geological Survey has recorded for it in the element you pick. The assays are as companies reported them, with no quality checks, and most holes were drilled by earlier explorers, not by whoever holds the ground today. Treat it as history, not a resource.
Use Explore to pick an element, set a minimum grade, slide through the years, search for a company or place, and dive into 16 deposits in 3D.
