Fathom Geophysics Newsletter 23

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Exploration News: Rock collections revival

MINING-heavy jurisdictions are putting real-life geological specimens at the front and center of their efforts to stimulate mineral exploration — through newly-built and upgraded drill core libraries. And pre-competitive digital catalogs containing extensive metadata and even 3D visual captures of rock samples may be par for the course before long.

Whenever it costs more time, money, space, and sweat equity to store drill core and rock hand samples than it took to win the material from the ground in the first place, these geological materials risk being sent on a one-way trip to the repository known as landfill.

Now that minerals producers have begun to shake off several years of demand doldrums, the governments of mining-intensive provinces are working earnestly to coax explorers back into the field, and are regarding new or refurbished specimen reference collections as worth the curation hassle.

Digital catalogs gain traction

Incorporating rock-sample metadata in pre-competitive exploration databases seems to be growing in importance among government geological surveys around the world. Some jurisdictions have been capturing field observations straight to databases in real time when a state-survey geologist is on the ground, bypassing the traditional pencil-and-notebook approach altogether. [1]

Among other innovations also capturing geoscientists' imagination is multi-view stereo photogrammetry. [2]

These are just some of the latest implementations of what has been a long-lived phenomenon.

"Field geologists have used digital workflows for several decades," said authors of a recent Computers & Geosciences journal paper on digital preservation of rock samples. [3]

But desktop 3D visual acquisition technology, such as laser scanning of samples, has only quite recently become more accessible to a wider demographic, and has led to an increasing number of practical applications, they said.

"With the rapid development of [3D digital rock-sample] databases containing vast amounts of information, it is important to develop tools concurrently that are capable of reading, manipulating, and presenting these data in a comprehensible platform," they said in their paper.

They said that in the future, and assuming that well-populated pre-competitive databases are available, the ability to access virtual geological samples rapidly may facilitate important mineral exploration decisions, such as first-phase site investigations.

For instance, examining geological samples in 3D virtual form and in a georeferenced manner would improve database users' knowledge of samples' spatial interrelationships and their regional geological context, they said.

Furthermore, knowing the sampling location of a virtual sample could provide insight about where to seek additional key samples, they said.

However, a crucial issue that has yet to be adequately addressed within virtual geological collections circles is the challenge of pooling legacy catalog-related metadata with existing reference collections' cyberinfrastructure in an interoperable way. [4] [5] [6] [7]

The problem involves the languishing of metadata offline in obsolete physical data-storage formats, and includes so-called 'dark data', defined as data that one doesn't even know one has on hand. The legacy-data problem won't go away by itself, according to those familiar with the topic, and is said to be actively growing.

Battle of the core shacks

When it comes to real-life collections of geological samples, more-recent efforts to entice explorers into putting boots on the ground again have included completed and promised work on physical storage facilities in:

  • South Australia [8]
  • Western Australia [9]
  • Queensland [10]
  • Yellowknife (Northwest Territories, Canada) [11]
  • Austin (Texas, USA) [12]

Builders of these sort of facilities seem cognisant that hauling around drill core trays on a daily basis is back-breaking work, and have begun to design smarter core-viewing spaces and core-retrieval systems.

Some also seem to be planning for the extended future. For instance, the Drill Core Reference Library in South Australia has enough spare storage capacity to cope with 20 more years' worth of incoming drill core and cuttings samples. [13]

References

[1] See, for example: A. Riganti, T.R. Farrell, M.J. Ellis, F. Irimies, C.D. Strickland, S.K. Martin and D.J. Wallace (2015) "125 years of legacy data at the Geological Survey of Western Australia: Capture and delivery", GeoResJ, 6, 175-194.

[2] D.G. De Paor (2016) "Virtual Rocks", GSA Today, August, 4-11.

[3] A.S. Harvey, G. Fotopoulos, B. Hall and K. Amolins (June 2017) "Augmenting comprehension of geological relationships by integrating 3D laser scanned hand samples within a GIS environment", Computers & Geosciences, 103, 152-163.

[4] S. Ramdeen (2015) "Preservation challenges for geological data at state geological surveys", GeoResJ, 6, 213-220.

[5] V. Johnson (ed.) (2015) "Legacy data: Looking at the past, thinking of the future", Australian Geoscience Information Association, 2015 Geoscience Seminar Proceedings, Occasional Paper 9, 83 pages. For example, in this collection of papers, one author said: "The legacy data window is getting shorter — legacy data is being created faster than ever before."

[6] J.F. Klump and K. Lehnert (2016) "Go digital! Making physical samples a valued part of the online record of science", American Geophysical Union, Fall General Assembly abstract.

[7] A. Averett and B.B. DeJarnett (2016) "University of Texas Bureau of Economic Geology's Core Research Centers: The time is right for registering physical samples and assigning international geosample numbers", American Geophysical Union, Fall General Assembly abstract.

[8] Australian Society of Exploration Geophysicists (2016) "News: The opening of the new South Australian Drill Core Reference Library", Preview, April 2016, 13-14.

[9] The West Australian (29 January 2016) "Drill core library expansion begins".

[10] APPEA (2016) "Queensland expands drill core storage and access", The Tech Drill in-house industry-innovation news column, www.appea.com.au.

[11] Government of Northwest Territories (25 September 2017), "Geological materials storage facility opens doors to future exploration", press release, www.gov.nt.ca.

[12] University of Texas at Austin's Jackson School of Geosciences (6 October 2017) "Bureau of Economic Geology breaks ground on new core research building", press release.

[13] Government of South Australia (2016) "South Australia mining investment guide", 39 pages.

About Fathom Geophysics

In early 2008, Amanda Buckingham and Daniel Core teamed up to start Fathom Geophysics. With their complementary skills and experience, Buckingham and Core bring with them fresh ideas, a solid background in geophysics theory and programming, and a thorough understanding of the limitations of data and the practicalities of mineral exploration.

Fathom Geophysics provides geophysical and geoscience data processing and targeting services to the minerals and petroleum exploration industries, from the regional scale through to the near-mine deposit scale. Among the data types we work on are: potential field data (gravity and magnetics), electrical data (induced polarization and electromagnetics), topographic data, seismic data, geochemical data, precipitation and lake-level time-lapse environmental data, and remotely-sensed (satellite) data such as Landsat and ASTER.

We offer automated data processing, automated exploration targeting, and the ability to tailor-make data processing applications. Our automated processing is augmented by expert geoscience knowledge drawn from in-house staff and from details relayed to us by the project client. We also offer standard geophysical data filtering, manual geological interpretations, and a range of other exploration campaign-related services, such as arranging surveys and looking after survey-data quality control.