What ONE common feature of volcanogenic massive sulfide deposits has been ignored since the 1960s?

Pssst, I have a fun quiz for you!

Are you a practical geologist who loves solving geological puzzles?

If so, I have a challenge for you in this post—it’s a simple and fun pattern recognition puzzle, and you’ll learn an interesting fact about volcanogenic massive sulfide (VMS) deposits that you probably didn’t know before.

Most ancient VMS deposits have one common feature that’s largely ignored by academics. I’m not going to tell you what it is—instead, I want you to try to see what I see by rapidly viewing multiple figures in this post that have come from journal articles spanning across nearly seven decades.

But first, some background…

This is the fifth in a series of posts that provides a counterpoint view of the syngenetic interpretation of ancient VMS deposits, an interpretation that’s largely accepted as factual by the economic geology community. Here are links to the previous posts: Post 1; Post 2, Post 3, and Post 4.

Our fact check at Maleev

In my last post I described the study Brett Davis and I did of the Maleev VMS deposit in eastern Kazakhstan—a deposit that is part of the fifth-largest field of syngenetic VMS deposits in the world, according to the USGS volume on ancient VMS deposits (Shanks and Thurston 2012). Brett and I concluded from our multiscale structural study that the Maleev deposit cannot be a synvolcanic deposit—it is epigenetic. This casts doubt on the origin of other economic massive sulfide deposits in the region, including the Zyryanov and Grekov deposits, which are within 20?km of the Maleev deposit.

What is interesting about these three deposits is that they all share one common feature, and this feature is readily seen in the geological maps that feature these deposits (see Figure?2 of Post 4). Interestingly, many published VMS deposits from around the world also show this same feature.

What is even more fascinating about this feature is that once identified, it becomes obvious to the observer, and you’ll start to notice that it’s actually difficult to find a VMS deposit that lacks this feature. Yet, ironically, this feature is rarely discussed by academics who research VMS deposits; therefore, it isn’t something geologists generally talk about or even look for when they’re searching for VMS deposits. After all, if the industry’s leading academics don’t talk about these features, then working geologists are unlikely to think about them or even think they are significant.

Let me demonstrate the complete lack of attention by academics to this particular feature that characterises VMS deposits. Do an internet image search for ‘VMS deposits’ or ‘VHMS deposits’—your search will return abundant illustrations of VMS deposits from the hundreds of published academic papers from about the 1960s onwards, and your results will look something like this:

Figure?1. Google image search results for ‘VMS deposits’ [as at 29 August 2021]

I can assure you that the single most common feature associated with VMS deposits that I want you to spot is nowhere to be seen in the first page of Google’s image search results. There’s one figure at the bottom of page?2 of the results that illustrates what I’m referring to, but the document that contains the image doesn’t discuss this feature.

What you get from the search are numerous images of the same hypothetical cartoon drawing of a sea floor massive sulfide system that is purported to represent ancient VMS deposits—this cartoon-like illustration has been recycled and passed down through several generations of geologists. What is completely lacking in the search results is an illustration of what a VMS deposit actually looks like in situ—there’s no fact-based map, section, or a 3D model that’s based on real drilling data. That’s what we need so that we know how to spot the feature I’m referring to. A conceptual cartoon just won’t show this feature because the academics who drew these conceptual models of VMS routinely ignored what’s actually there.

Can you spot it?

Below are 30?figures (from publications dating back to 1953) of massive sulfide deposits that, in 2021, are regarded as syngenetic VMS deposits; they all appear in the USGS database of VMS deposits (Shanks and Thurston 2012). See if you can spot the one feature that I found to be commonly associated with ancient VMS deposits. It may seem overwhelming as there are a lot of images, but there is no need to dwell on each one. ?The best way to do this quiz is to flip through the images quickly as it’s much easier to spot the association by not studying these images too closely.

Figure?2. Noranda Mining Camp, Quebec; VMS deposits are shown as black dots (Gibson and Galley 2007)

Figure?3. Winston Lake VMS deposits, Ontario (Lodge et al. 2014)

Figure?4. Parys Mountain VMS, Wales (Barrett and MacLean 1997)

Figure?5. Eskay Creek VMS, British Columbia (Sherlock et al. 1999)

Figure?6. Hitachi massive sulfide deposit, Japan (Shimada 1955)

Figure?7. Brunswick VMS deposit, New Brunswick (Goodfellow 2007)

Figure?8. Boliden VMS deposit, Sweden (Hannington et al. 1997)

Figure?9. Matagami VMS field, Quebec (Ioannou et al. 2007)

Figure?10. Neves Corvo deposit, Iberian Pyrite Belt, Portugal (Oliveira et al. 1997)

Figure?11. Kidd Creek, Ontario, VMS deposit (in black) (Houston and Taylor 1999)

Figure?12. Izok Lake deposit, Nunavut, Canada, with its vertical projection in red (Makvandi et al. 2016)

Figure?13. Windy Craggy VMS, British Columbia (Peter and Scott 1997)

Figure?14. Kutcho Creek VMS, British Columbia (Barrett and MacLean 1997)

Figure?15. Panorama VMS deposits, Pilbara region, Western Australia; deposits are indicated as red diamonds (Martindale et al. 2014)

Figure?16. Besshi and associated VMS deposits, Shikoku Island, Japan (Kanehara and Tatsumi 2007)

Figure?17. Geco deposits from Manitouwadge, Ontario (Petersen 1986)

Figure?18. Sabzevar basin VMS deposits, Iran (Maghfouri et al. 2016)

Figure?19. Elizabeth massive sulfide deposit, Vermont (McKinstry and Mikkola 1954)

Figure?20. Fyre Lake massive sulfide deposit (Peter et al. 2007)

Figure?21. Captain’s Flat Pb-Zn-Cu deposit, New South Wales (red dot) (Edwards and Baker 1953)

Figure?22. Flin Flon deposit, Manitoba (Ames et al. 2016)

Figure?23. Myra Falls VHMS deposit, Vancouver Island, British Columbia (Jones et al. 2005)

Figure?24. DeGrussa VMS deposit, Western Australia (Hawke et al. 2015)

Figure?25. Woodlawn, New South Wales (Glen 1995)

Figure?26. Bisha deposit, Eritrea (Barrie et al. 2007)

Figure?27. Hadal Awatib VMS, Sudan (Plyley et al. 2009)

Figure?28. Kristineberg, Skellefte?, Sweden (?reb?ck et al. 2005)

Figure?29. Rambler and Ming deposits, Newfoundland (Pilote et al. 2017)

Figure?30. Mt Lyell, Tasmania (Corbett 2001; Noll and Hall 2005)

Figure?31. San Antonio, Iberian Pyrite Belt, Spain (Martin-Izard et al. 2015)

Did you spot the feature that’s commonly associated with VMS deposits?

Yes, it’s folding.

When you see all these images one after another and can compare them all in the one place, it’s obvious, right?

If you’re not convinced—perhaps you think I’ve rigged this quiz with pictures of VMS deposits that only show folding—then do your own search for any ancient VMS deposit that’s listed in the USGS VMS database (Shanks and Thurston 2012) and find the original article that describes the deposit, then look at the figures.

You will find very few deposits that are NOT associated with folding or some type of ductile deformation.

I suspect that the spatial association of brittle-ductile strain and accompanied folding is more common than the association of actual massive sulfide deposits with appropriate volcanogenic host rocks. Yes, that’s right. Although directly contravening what one would expect from observing modern sea floor massive sulfide deposits that are in contact with volcanic rocks, there are numerous ancient VMS deposits that are near volcanogenic rocks, but don’t quite physically touch them. Many VMS deposits are situated in slates, which all sedimentologists would categorise as originating from mudstones that are typically deposited in quiescent geological periods—a complete contradiction to what I expected from a volcanogenic environment, yet such arguments are repeatedly published in reputable economic geology journal articles.

Economic geology researchers who interpret these deposits as being synvolcanic have collectively decided to completely ignore folding—the most prominent feature associated with VMS deposits—as being unimportant. This is because they view all deformation to occur after the mineralisation. From the late 1950s when the first journal papers on the syngenetic origin of massive sulfides started to appear in the modern literature and until the present day (2021), they have routinely ignored deformation.

This time span represents at least four generations of economic geology researchers, so it’s not surprising that very few contemporary researchers are aware of the close association of ductile deformation with VMS deposits. Nearly all VMS researchers treat deformation as an inconvenient annoyance that overprints what they assume is a primary syngenetic mineralisation event, yet they rarely document what the actual host rocks look like in situ at the deposit-scale. Instead, they swamp their long articles with geochemical tables, plots, and cartoon representations of what they imagine the deposit looked like before deformation.

Working geologists who read the papers on VMS are also completely unaware of the general association of ductile deformation with VMS occurrences. Having said this, there should be examples of VMS deposits that are not hosted in deformed rocks.?Because very few undeformed deposits have been documented, it seemed to me that Kuroko deposits would be a perfect place to start to see what a true undeformed VMS deposit looks like. Kuroko is the subject of my next post in this series, but you’ll find it hard to believe what I discovered.?

References?(most articles are available?here)

Ames, D.E., Galley, A.G., Kjarsgaard, I.M., Tardif, N., Taylor, B.E., 2016. Hanging-Wall Vectoring for Buried Volcanogenic Massive Sulfide Deposits, Paleoproterozoic Flin Flon Mining Camp, Manitoba, Canada. Economic Geology, 111, 963–1000.

?reb?ck, H., Barrett, T.J., Fagerstr?m, P., Abrahamsson, S., 2005. The Palaeoproterozoic Kristineberg VMS deposit, Skellefte district, northern Sweden. Part?I. Mineralium Deposita 40, 368–395.

Barrett, T.J., McLean, W.H., 1997. Volcanic sequences, lithogeochemistry, and hydrothermal alteration in some bimodal volcanic-associated massive sulfide systems. Society of Economic Geologists, Reviews in Economic Geology 8, 101–132.

Barrie, C.T., Nielsen, F.W. and Aussant, C.H., 2007. The Bisha Volcanic-Associated Massive Sulfide Deposit, Western Nakfa Terrane, Eritrea. Economic Geology, 102, 717–738.

Corbett, K.D., 2001. New Mapping and Interpretations of the Mount Lyell Mining District, Tasmania: A Large Hybrid Cu-Au System with an Exhalative Pb-Zn Top. Economic Geology, 96, 1089–1122.

Edwards, A.B., Baker, G., 1953. The composition of the lead-zinc ores at Captain's Flat, NSW. Proceedings of the AusIMM. 170, 103–131.

Gibson, H., Galley, A., 2007. Volcanogenic massive sulphide deposits of the Archean, Noranda District, Quebec. Special Publication No.?5, Mineral Deposits Division, Geological Association of Canada, 533–552.

Glen, R.A., 1995. Thrusts and thrust-associated mineralization in the Lachlan Orogen. Economic Geology, 90, 1402–1429.

Goodfellow, W.D., 2007. Metallogeny of the Bathurst Mining Camp, northern New Brunswick. Geological Association of Canada, Mineral Deposits Division, Special Publication No.?5, 449–469.

Hannington, M.D., Poulsen, K.H., Thompson, J.F.H., Sillitoe, R.H., 1997. Volcanogenic gold in the massive sulfide environment. Society of Economic Geologists, Reviews in Economic Geology 8, 325–356.

Hawke, M.L., Meffre, S., Stein, H., Hilliard, P., Large, R., Gemmell, J.B., 2015. Geochronology of the DeGrussa volcanic-hosted massive sulphide deposit and associated mineralisation of the Yerrida, Bryah and Padbury Basins, Western Australia. Precambrian Research, 267, 250–284.

Houston, D.L., Taylor, B.E., 1999. Genetic significance of oxygen and hydrogen isotope variations at the Kidd Creek volcanic-hosted massive sulfide deposit, Ontario, Canada. Economic Geology, Monograph 10, 335–350.

Ioannou, S.E., Spooner, E.T.C., Barrie, T.D., 2007. Fluid temperature and salinity characteristics of the Matagami volcanogenic massive sulfide district, Quebec. Economic Geology 102, 691–715.

Jones, S., Herrmann W., Gemmell, J.B., 2005. Short Wavelength Infrared Spectral Characteristics of the HW Horizon: Implications for Exploration in the Myra Falls Volcanic-Hosted Massive Sulfide Camp, Vancouver Island, British Columbia, Canada. Economic Geology, 100, 273–294.

Kanehara, K., Tatsumi, T., 1970. Bedded cupriferous iron sulphide deposits in Japan, a review. In: Tatsumi, T., ed. Volcanism and Ore Genesis. Univ. Tokyo Press, 51–76.

Lodge, R.W.D., Gibson, H.L., Stott, G.M., Franklin, J.M., Hamilton, M.A., 2014. Geodynamic Reconstruction of the Winston Lake Greenstone Belt and VMS Deposits: New Trace Element Geochemistry and U-Pb Geochronology. Economic Geology 109, 1291–1313.

Maghfouri, S., Rastad, E., Mousivand, F., Lin, Y., Zaw, K., 2016. Geology, ore facies and sulfur isotopes geochemistry of the Nudeh Besshi-type volcanogenic massive sul?de deposit, southwest Sabzevar basin, Iran. Journal of Asian Earth Sciences, 125, 1–21

Makvandi, S., Beaudoin, G., McClenaghan, Layton-Matthews, D., 2016. The surface texture and morphology of magnetite from the Izok Lake volcanogenic massive sul?de deposit and local glacial sediments, Nunavut, Canada: Application to mineral exploration. Journal of Geochemical Exploration 150, 84–103.

Martindale, J., Hagemann, S., Huston, D., Danyushevsky, L., 2014. Integrated stratigraphic–structural–hydrothermal alteration and mineralisation model for the Kangaroo Caves zinc–copper deposit, Western Australia. Australian Journal of Earth Sciences 61, 159–185.

Martin-Izard, A., Arias, D., Arias, M., Gumiel, P., Sanderson, D.J., Casta?on, C., Lavandeira, A., Sanchez, J., 2015. A new 3D geological model and interpretation of structural evolution of the world-class Rio Tinto VMS deposit, Iberian Pyrite Belt (Spain). Ore Geology Reviews, 71, 457–476.

McKinstry, H.E., Mikkola, A.K., 1954. The Elizabeth Copper Mine, Vermont. Economic Geology 49, 1–30.

Noll, C.A., M Hall, M., 2005. Great Lyell Fault, western Tasmania: a collage of Middle and Late Cambrian growth faults reactivated during Devonian orogenesis, Australian Journal of Earth Sciences, 52, 427–442.

Oliveira, J.T., Pacheco, N., Carvalho, P., Ferreira, A., 1997. Field Trip #1: The Neves Corvo Mine and the Paleozoic Geology of Southwest Portugal. In F.J.A.S. Barringa, and D. Carvalho, eds, Geology and VMS deposits of the Iberian Pyrite Belt. SEG Neves Corvo Field Conference 1997, Guidebook Series Volume 27, 21–71.

Peter, J., Scott, S.D., 1997. Windy Craggy, northwestern British Columbia: The world’s largest Besshi-type deposit. Society of Economic Geologists, Reviews in Economic Geology 8, 261–296.

Peter, J.M., Layton-Matthews, D., Piercey, S., Bradshaw, G., Paradis, S., Boulton, A., 2007. Volcanic-hosted massive sulphide deposits of the Finlayson Lake District, Yukon. Geological Association of Canada, Mineral Deposits Division, Special Publication No. 5, 471–508.

Petersen, E., 1986. Tin in volcanogenic massive sulfide deposits: An example from the Geco Mine, Manitouwadge District, Ontario, Canada. Economic Geology 81, 323–342.

Pilote, J-L., Piercey, S.J., Mercier-Langevin, P., 2017. Volcanic and Structural Reconstruction of the Deformed and Metamorphosed Ming Volcanogenic Massive Sulfide Deposit, Canada: Implications for Ore Zone Geometry and Metal Distribution. Economic Geology, 112, 1305–1332.

Plyley, B., Kachrillo, J-J., Bennett, M., Bosc, R., Barrie, T., 2009. Hadal Awatib East Cu-Au VMS Deposit, Sudan Resource Estimates. NI43-101 Technical Report, La Mancha Resources Inc.

Shanks, W.C.P., Thurston, R., 2012. Volcanogenic massive sulfide occurrence model (No. 2010–5070–C), U.S. Geological Survey Scientific Investigations Report. U.S. Geological Survey, Virginia.

Sherlock, R.L., Roth, T., Spooner, E.T.C., Bray, C.J., 1999. Origin of the Eskay Creek precious metal-rich volcanogenic massive sulfide deposit: fluid inclusion and stable isotope evidence. Economic Geology 94, 803–824.

Shimada, M., 1955. On the folding structure in the eastern area of the Hitachi mine. Study on the geology and ore deposit of the Hitachi mine. Mining Geology, 5, 102–116 (in Japanese).

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Jun Cowan is a structural geological consultant, specialising in the interpretation of mineral deposits at the deposit-scale. He is the conceptual founder of Leapfrog Software, which is now being used by many international mining and mineral exploration companies—a software that resulted from private R&D collaboration undertaken by a joint venture between SRK Consulting Australasia (where Jun worked) and New Zealand company, ARANZ. Out of his home in Fremantle, Western Australia, he consults to mineral industry clients around the world and enjoys sharing his crazy ideas with his clients and online colleagues. This and other articles, mainly focused on geological subjects, are available from?LinkedIn.

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