563 trays of real drill core from seven South Australian discoveries and mines, scanned metre by metre at the state's core library. Pull a tray, light up the assays along the core and learn to log it.
Every diamond drill hole comes out of the ground as a column of rock about the width of a broom handle, laid in trays a metre long in the order it was cut. Mining companies and governments keep those trays in core sheds and core libraries for decades, because the core is the only direct sample of what lies underground. South Australia's Drill Core Reference Library at Tonsley holds core from over 130 years of exploration, and its HyLogger scans trays with visible and infrared light, photographing every centimetre and reading the minerals from their spectra. The scans are shared through AuScope's National Virtual Core Library.
This shed holds 7 of those holes: 2,886 metres of scanned core in 563 trays, with 1,889 assays from the government's open SARIG database lined up against the photographs. In the 3D view each rack is one hole and each tray end glows by the best assay inside it. Pull a tray onto the bench to see the core up close, switch between the photograph, the assays and the minerals, follow the strip log of the whole hole, and walk through how a geologist logs core and turns assays into the interval you read in a company release. It pairs with our guide What is drill core? and with how to read drill results.
| Deposit | Hole | Drilled by | Year | Scanned | Trays | Best interval (our calculation) |
|---|---|---|---|---|---|---|
| Carrapateena | CAR002 | R.M.G. Services Pty Ltd. | 2006 | 240–654 m | 77 | 80 m at 2.69% from 469.0 m |
| Prominent Hill | DDHURN1 | Minotaur Resources Ltd. | 2001 | 108–720 m | 110 | 152 m at 1.11% from 428.0 m |
| Olympic Dam | RD33 | BHP Billiton OD Corp. Pty Ltd. | 1980 | 306–697 m | 68 | 34 m at 1.99% from 375.0 m |
| Hillside | HDD-018 | Rex Minerals (SA) Pty Ltd. | 2008 | 15–550 m | 121 | 63 m at 2.72% from 218.0 m |
| Kanmantoo | KTDD149 | Hillgrove Resources Ltd. | 2007 | 0–589 m | 99 | 33 m at 1.83% from 281.0 m |
| Paris | PPDH023 | Investigator Resources Ltd. | 2012 | 42–250 m | 60 | 10 m at 2,823 g/t from 165.0 m |
| Challenger | 98CDDH0002 | Dominion Mining Ltd. | 1998 | 3–140 m | 28 | 7.1 m at 10.50 g/t from 198.2 m |
At a 0.2% cut-off the open assays join into 80 m at 2.69% from 469.0 m (our arithmetic, see below).
At a 0.2% cut-off the open assays join into 152 m at 1.11% from 428.0 m (our arithmetic, see below).
At a 0.2% cut-off the open assays join into 34 m at 1.99% from 375.0 m (our arithmetic, see below).
At a 0.2% cut-off the open assays join into 63 m at 2.72% from 218.0 m (our arithmetic, see below).
At a 0.2% cut-off the open assays join into 33 m at 1.83% from 281.0 m (our arithmetic, see below).
At a 30 g/t cut-off the open assays join into 10 m at 2,823 g/t from 165.0 m (our arithmetic, see below).
At a 0.3 g/t cut-off the open assays join into 7.1 m at 10.50 g/t from 198.2 m (our arithmetic, see below).
The photographs are the HyLogger's own scans, one row of a tray at a time. The library records the depth of every scan sample, so each point across a photograph has a depth, and the assays and minerals are placed on the core by that depth. Assays are the open SARIG laboratory results for each hole, shown as % for copper, lead, zinc and iron, g/t for gold and silver and ppm for uranium. The minerals are the HyLogger's automated interpretation (TSA) of the shortwave and thermal infrared spectra in half-metre steps; dark, iron-rich or very fine rock often scans as "aspectral" and is left uncoloured.
The intervals are our own arithmetic, not the companies' published figures: we join touching samples at or above the cut-off, allow up to 2 m of lower-grade samples inside an interval while its average stays above the cut-off, and report the length-weighted average. Companies choose their own rules and often report different widths, so a figure here can differ from the one in the original release. The holes were drilled by the companies named, at the time named; several of the deposits have changed hands since. Nothing here rates a company or a project, and it is not investment advice.
See more of South Australia's open drilling on the Under South Australia map, and real drill results in 3D on our open 3D drill models.
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Pictures: Timna in de Negevwoestijn; rotspartij "de zuilen van Salomo", Poll, Willem van de / Europeana (Public Domain Mark 1.0); The laboratories of Marie and Pierre Curie, Paris: room where experiments on uranium ore took place. Photograph, ca. 1900., Unknown (Wellcome Collection) (Public Domain Mark 1.0).