Those who subscribe to Geoscience Australia’s Minerals Alert may have noticed a call petrophysical legacy datasets to be ingested into the new Rock Properties Database (beta version). AGIA contacted Dr Ian Roach (Southern Thomson Orogen Project Activity Leader, Geophysical Acquisition and Processing, GA) to find out more about the database and the type of data GA would be interested in receiving, and he has kindly provided the fulsome description below.
“We’re keen to collate and publicize as much legacy petrophysical data as we can, to help promote geophysical modelling for mineral exploration and deep earth geophysics and to give these data a permanent home. At present the Rock Properties Database contains about 120,000 records of data, mostly mass density and magnetic susceptibility and a little magnetic remanence, thermal conductivity and a few other bits and bobs. Data are primarily from the Earth’s surface, but we also have the capacity to serve data derived from borehole geophysics. Each record is labelled with 3D coordinates, stratigraphy, lithology and (hopefully) some metadata describing how the data were collected (but this is not always available)…
The data can be downloaded using our discovery and delivery tool, but also directly through web-enabled software (GIS or 3D software) via the web services we provide. The data are designed to be machine readable and future-proof, so they can be read and processed by geophysical modelling software on supercomputers in the cloud.
We are collaborating with the State and Territory geological surveys which are keen to add their own legacy data, and are in talks with some of the larger mining houses too. We are keen to take legacy data provided it can be organised into a format that we can easily process – you will appreciated that reformatting data is a very time consuming job! I can provide detailed information on what is required.
For the future, we plan to expand the database by hosting the State and Territory legacy data and perhaps even data from the Oceania region. We are also keen for donations of open source data from mining companies and academics. There is an expansive list of suggested requirements, but put simply, we’d like well described data including:
· A unique sample number or sample ID
· Whether the site is a surface sample or a borehole (for boreholes we also need the hole orientation, hole length and a deviation survey if one exists)
· XYZ coordinates in a recognised datum and projection (GDA94/WGS84 preferred, otherwise an Australian UTM projection)
· A description of the datum and projection used, including the vertical datum (mean sea level, ellipsoid, geoid)
· An estimation of the positional accuracy of the coordinates (e.g., 100 m for a 1:100,000 map sheet, 30 m for an old GPS, 1 m for a DGPS)
· The property collected (e.g. dry bulk mass density, magnetic susceptibility, magnetic remanence)
· The unit of measure (e.g. g/cm3, SIx10-5)
· An estimation of uncertainty (e.g., percent error, standard deviation)
· Who collected the data
· The instrument make-model-serial number if possible
· A recognised stratigraphic unit and a lithological description of the sample
· A reference to the data (e.g. a URL, a report, a book)
There’s more, but you get an idea of the level of detail we’re trying to capture. This all goes towards everyone’s confidence in the data.
So, we’re keen to collect petrophysical data that people have collected for their research projects and on minerals tenements. This can be as simple as density and magnetic susceptibility, and as complex as magnetic remanence.”
For more information please contact Dr Ian Roach, email:email@example.com, phone: +61 2 6249 9683