Turnstone Geological Services

Turnstone: Past, Present and Near-Future

Turnstone was incorporated federally in Canada in July 1985 as a platform for the integration of field, laboratory and computer- assisted projects in mineral exploration. Over the past 39 years, the initial focus on economic geology has broadened, as described below, following both the demands of the clientele and the expanding interests of the principal of the firm, consulting geologist and mineralogist Graham Wilson. Extensive use of petrographic methods, including electron microprobe and other advanced techniques, are useful in economic and genetic evaluations of many types of mineral deposit. Many projects benefit from a more "classical", hands-on approach, a blend of field visits and sampling, assay and basic mineralogical evaluation.

Time marches on, and, though consulting has continued through 2023, Wilson is turning from consulting to the related goals of a) finding a home for the library (indexed via twin bibliographies) and collections of rocks, minerals and meteorites, and b) editing, writing and publishing books in the coming years, using the in-house resources built up in the Turnstone years, and before. As of August 2024, Turnstone was dissolved as a federal corporation, but lives on through collections, libraries, and of course this web site. The work continues!

Many Turnstone consulting projects have been carried out on gold, silver, nickel-copper-platinum, massive sulphide, skarn, industrial mineral and other types of mineralization for well over 100 clients in industry, government and academia. 500-plus Turnstone reports have been completed. Archival material generated in this period include more than 3,800 detailed descriptions of rocks, ores and other samples under the microscope.

Various avenues of research have also fed Turnstone's diverse collection of over 4,000 reference specimens of rocks and minerals. A number of these samples have become the focus of detailed research (e.g., a rare platinum-group mineral grain, a comparatively large specimen despite its 0.5-mm size, has been examined in terms of its mineral association, chemistry and optical properties --- view optical spectrum [113 kb]).

Image: Banded silica (chalcedony and amethyst) in a gold-mineralized, sulphide-bearing quartz vein from the Temascaltepec prospect, Mexico state, Mexico. Polished thin section viewed in transmitted, cross-polarized light, horizontal field of view 2.5 mm. Sample 800, Description 293.

Take a closer look at this image [179 kb] .

The Design, Compilation and Maintenance of MINLIB and other Databases

Project-driven research and systematic literature searches have both provided public-domain literature sources for a number of well-indexed bibliographic databases conceived by Graham Wilson and developed at Turnstone, such as the predominantly Earth-science-oriented MINLIB (described below) and the human geography and geopolitics of the WORLD database (these systems combined include >117,000 records, as of 2024).

The development and application of detailed computer databases of worldwide scope facilitates the efficient management of all the observations gathered and materials reviewed during Turnstone projects and other research. The evolution of these support systems encompasses petrographic, experimental, bibliographic and other data. Although the majority of Turnstone reports are confidential, the bibliographies are almost entirely composed of freely-available publications, such as books, journal articles and abstracts.

The affordable publication of a version of Turnstone's MINLIB annotated Earth- science bibliography, illustrated with suites of educational images, is a long-term, high-priority Turnstone project, pursued as time allows. Both the database and the associated suites of photographs will be indexed in order to both satisfy professional needs and provide non-specialist users with meaningful access to the illustrations plus non-technical literature on natural history, geology and the solar system. MINLIB, initiated on 09 August 1983, has currently been growing for some 41 years.

MINLIB, undergoing constant updating from many sources, now (July 2024) comprises more than 92,000 records, each one flagged in a number of ways (bibliographic citation, up to 30 lines of keywords, dozens of logical [yes/no] fields) for ease of retrieval with a maximum success rate. Success in this context can be defined as the largest number of relevant records retrieved, and the highest possible ratio of useful references to accidental "false hits". Heavily-indexed structures such as MINLIB and the geopolitically-oriented WORLD (over 25,000 records, July 2024) are very efficient, and in specialized examples may actually generate a higher number of useful "hits" than far larger compilations of data, including the World Wide Web.

More than 300 of the many topics, themes and sources well-integrated into MINLIB are listed in the following table, with the number of records returned by searches in Oct. 2014 to Apr. 2015 (a few extra searches in 2017 or after are flagged bold *). The HOLDINGS "metadatabase" of which this table is a very small part may be installed on this site at a future date. The in-house rule-of-thumb is that the database coverage for a subject can be considered "mature" once the appropriate keyword selection returns a minimum of 300 valid records. HOLDINGS lists well over 400 such subjects as examples of MINLIB coverage. Note that some topics, especially specific items such as a mineral or fossil species, a country or locality, can be sought with confidence that most or all pertinent records will be found. Extra themes are added from time to time and offer partial selections of wide topics, such as "local geology" or "geochemical exploration".

In addition to economic geology and mineral exploration, meteorites, impact events and planetary science provide an additional strong focus (see an example on Indian meteorites, and a note on the classification of a chondritic stony meteorite. Further examples of meteorite work can br found through the Index of Meteorite Topics. Aspects of environmental science and archaeology are also well-represented. Topics relevant to research at the IsoTrace Laboratory at the University of Toronto, a unique facility for ultra-sensitive analysis and radiocarbon dating, are extensively documented in MINLIB. IsoTrace will be "reincarnated" soon at the André E. Lalonde AMS Facility at the University of Ottawa.

More than 99% of MINLIB is non-confidential, "open-file" material, intended for publication in suitable media, such as CD-ROM, DVD-ROM or a web-based interface. While MINLIB highlights economic geology and mineralogy, its rich thesaurus-based keyword structure can provide surprising retrieval beyond its major themes, for topics as diverse as Quaternary geology, fossils and lightning strikes! It will also serve as an index to acronyms and other confusing jargon. Examples of both technical and `popular' records of MINLIB and WORLD databases are available on this site.