Michael L. J. Maher, PhD, and Maxim Ryskin, PhD
Materials Engineering Group, WSP Golder, Whitby, Ontario, Canada

Part of the book: Pyrite and Pyrrhotite: Managing the Risks in Construction Materials and New Applications

Chapter DOI: https://doi.org/10.52305/DYTV1219

Abstract

This chapter is in response to a recent spate of cases of structural damage in buildings caused by the use of aggregates that contain reactive sulfides, typically pyrite or pyrrhotite. Since these problems seem to predominantly hit residential construction, the huge financial and emotional impacts on residents gets the attention of governments. In addition to establishing how homeowners will get redress for the damages, governments also want to see protocols in place to provide confirmation that the damage can be attributed to reactive sulfides and to categorize the severity of the damage. For engineering practitioners, tasked with investigating the problems, they need to be able to apply the protocols so that objective and repeatable results are achieved. Since the development of pyritic damage is slow and progressive, the issue of risk of future more severe damage is a key challenge to establishing the scope and costs of remedial works. In this chapter, we describe two categorization protocols, one developed in Québec and the other in Ireland. While both these protocols have been successful in assisting engineers and geologists in investigating pyrite-induced structural problems, they have some limitations. Thus, most of the chapter is devoted to evaluating an investigative technique based on the geochemistry of the aggregate that may enhance current practices. The proposed analytical technique has promise to assist in the risk categorization of aggregates based on the fact that the reactivity of pyrite is established by its original depositional history. Using analysis of select trace elements, which are markers for the abundance, form and reactivity of pyrite, we hope to be able to establish the depositional history and in turn develop numerical thresholds to assist geologists and engineers in establishing the risk of future pyrite-induced expansion and its severity. The research objective was to explore whether there was a link between the concentrations of the selected redox-sensitive trace elements (Mo, U, V, Re, and Se) in aggregates and the Risk of Pyrite Expansion (RPE). The technique is demonstrated using test data from actual samples recovered from damaged and undamaged houses, as well as from source quarries. From this analysis, Mo and the ratio of Mo to U enrichments in aggregate, seem to provide the best options for distinguishing between RPE categories. Using the same laboratory test data, we also explore the possibility of using trace element data to match unknown aggregate samples with their source quarries. Traceability of aggregates is a key component of an investigation when performance problems arise. In the absence of chain of custody type documentation, a ‘fingerprinting’ methodology would be useful for matching aggregate samples to original source. Using sets of either 50 or 20 major and minor trace elements, good results have been achieved in differentiating aggregate samples from different quarries, even in cases where lithologies were generally similar.

Keywords: aggregates, categorization, pyrite risk, trace element analysis, source matching

References

Algeo, T. J. and Maynard, J. B. (2004). Trace-element behavior and redox facies in core shales of Upper
Pennsylvanian Kansas-type cyclothems. Chemical Geology, 206: 289 – 318.
Algeo, T. J. and Lyons, T. W. (2006). Mo-total organic carbon covariation in modern anoxic marine
environments: implications for analysis of paleoredox and paleohydrographic conditions.
Paleoceanography, 21 (1), PA1016. http://dx.doi.org/10.1029/2004PA001112.
Algeo, T. J. and Maynard, J. B. (2008). Trace-metal covariation as a guide to water-mass conditions in ancient
anoxic marine environments. Geosphere, 4(5):872-887.
Algeo, T. J. and Tribovillard, N. (2009). Environmental analysis of paleoceanographic systems based on
molybdenum–uranium covariation. Chemical Geology, Volume 268, Issues 3–4, 211-225.
Anderson, W. A. (2008). Foundation problems and pyrite oxidation in the Chattanooga Shale, Estill County,
Kentucky. Kentucky Geological Survey, Report of Investigations 18, Series X11, Lexington, Kentucky.
Armstrong, J. G. T., Parnell, J., Bullock, L. A., Perez, M., Boyce, A. J. and Feldmann, J. (2018). Tellurium,
selenium and cobalt enrichment in Neoproterozoic black shales, Gwna Group, UK: Deep marine trace
element enrichment during the Second Great Oxygenation Event. Terra Nova, 30: 244-253.
Awan, R. S., Liu, C., Yang, S., Wu, Y., Zang, Q., Khan, A. and Li, G. (2021). The occurrence of vanadium in
nature: its biogeochemical cycling and relationship with organic matter—a case study of the Early
Cambrian black rocks of the Niutitang Formation, western Hunan, China. Acta Geochim, 40: 973 – 997.https://doi.org/10.1007/s11631-021-00482-2
Bellaloui, A., Ballivy, G., and Rivard, P., (2003), Neutralisation du Potentiel Gonflement des Remblais de
Fondation par des Injections de Coulis Spéciaux [Neutralization of the Potential Swelling of Foundation
Embankments by Special Grout Injections], Final report, presented to the Société canadienne
d’hypothèques et de logement, GR 03-05-01.
Berner, R. A. (1984). Sedimentary pyrite formation: An update. Geochimica et Cosmochimica Acta, 48(4):605-615.
Bérubé, M. A., Locat, J., Gélinas, P., Chagnon, J Y. and Lafrancois, P. (1986). Black shale heaving at Sainte-
Foy, Québec, Canada. Can. J. of Earth Sci., 23: 1774-1781.
Blood, R. (2018). Deposition, Diagenesis and Hydrocarbon Generation in the Ordovician Point Pleasant
Limestone and the Devonian Marcellus Shale: Comparing and Contrasting Two Appalachian Basin
Unconventional Reservoirs. Search and Discovery Article #51539.
BNQ (2003), BNQ 2560-500: Aggregates – Determining the Sulphate Swelling Potential Petrographic Index
(SPPI) of Granular Materials – SPPI Evaluation Test Method, Bureau de Normalisation du Québec,
Brocks, J. J., Love, G. D., Summons, R. E., Knoll, A. H., Logan, G. A. and Bowden, S, A. (2005). Biomarker
evidence for green and purple sulphur bacteria in a stratified Palaeoproterozoic sea. Nature, 437 (7060):866–870.
Bromley, A. (1999). The accelerated degradation of concrete in south west England. 7th European Concrete Symposium, Delft, Netherlands.
Chappaz, A., Lyons, T. W., Gregory, D. D., Reinhard, B. C., Gill, C. and Large, R. R. (2014). Does pyrite act
as an important host for molybdenum in modern and ancient euxinic sediments? Geochim. Cosmochim. Acta, 74: 203−214.
Chappaz, A., Glass, J. B. and Lyons, T. W. (2016). Molybdenum. W. M. White (ed.), Encyclopedia of Geochemistry. Springer, Cham.
Cheng, M., Li, C., Zhou, L. and Xie, S. C. (2015). Mo marine geochemistry and reconstruction of ancient ocean
redox states. Sci. China D Earth Sci., 58: 2123-2133.
Cole, D. B., Zhang, S. and Planavsky, N. J. (2017). A new estimate of detrital redox-sensitive metal
concentrations and variability in fluxes to marine sediments. Geochimica et Cosmochimica Acta, Vol.
215: 337-353. ISSN 0016-7037, https://doi.org/10.1016/j.gca.2017.08.004
Colodner, D., Sachs, J., Ravizza, G., Turekian, K., Edmond, J. and Boyle, E. (1993). The geochemical cycle
of rhenium: a reconnaissance. Earth and Planetary Science Letters, Vol. 117, Issues 1 – 2: 205-221.
Condie, K. C. (1993). Chemical composition and evolution of the upper continental crust: Contrasting results
from surface samples and shales. Chemical Geology, 104: 1-37.
Cormier, Marie-Claude. (2000). La Pyrite – Analyse statistique de rapports d’expertise CTQ-M200 relevant
les dommages structuraux attribuables à la présence de pyrite dans les remblais sous dalles de bâtiments
résidentiels [Pyrite – Statistical analysis of CTQ-M200 expert reports identifying structural damage
attributable to the presence of pyrite in under slab fills of residential buildings], École Polytechnique de Montréal.
Crusius, J., Calvert, S., Pedersen, T. and Sage, D. (1996). Rhenium and molybdenum enrichments in sediments
as indicators of oxic, suboxic and sulfidic conditions of deposition. Earth and Planetary Science Letters, Vol. 145, Issues 1–4: 65-78.
CTQ. (2001). Protocole d’expertise sur bâtiments résidentiels existants [Expert protocol for existing residential
buildings], Protocole CTQ-M200, Comité Technique Québécois d’étude des Problèmes de Gonflement associés à la Pyrite, Version 2.0.
Cumberland, S. A., Douglas, G., Grice, K. and Moreau, J. W. (2016). Uranium mobility in organic matter-rich
sediments: A review of geological and geochemical processes. Earth-Science Reviews, Vol. 159: 160-185.
Czerewko, M. A. and Cripps, J. C. (2022). Investigation of destructive ground heave attributed to pyritic fill
affecting new-build properties in the Dublin area of Ireland. Engineering Geology, 299,
Dahl, T. W., Ruhl, M., Hammarlund, E. U., Canfield, D. E., Rosing, M. T. and Bjerrumc, C. J. (2013). Tracing
euxinia by molybdenum concentrations in sediments using handheld X-ray fluorescence spectroscopy
(HHXRF). Chemical Geology 360–361, 241–251.
Dahl, T. W., Chappaz, A., Hoek, J., McKenzie, C. J., Svane, S. and Canfield, D. E. (2017). Evidence of
molybdenum association with particulate organic matter under sulfidic conditions. Geobiology, 15:311−323.
DOECLG. (2012). Report of the Pyrite Panel. Department of the Environment, Community and Local Government, Dublin.
de Vos, W., Tarvainen, T., Salminen, R., plus 35 authors. (2006). Geochemical atlas of Europe. Part 2.
Interpretation of geochemical maps, additional tables, figures, maps, and related publications. Selenium,
pp. 331-332. Geological Survey of Finland.
Ding, J., Zhang, J., Tang, X., Huo, Z., Han, S., Lang, Y., Zheng, Y., Li, X. and Liu, T. (2018). Elemental
Geochemical Evidence for Depositional Conditions and Organic Matter Enrichment of Black Rock Series
Strata in an Inter-Platform Basin: The Lower Carboniferous Datang Formation, Southern Guizhou,
Southwest China. Minerals, 8(11), 509. https://doi.org/10.3390/min8110509.
Dornan, T., Goodhue, R. and Reigler, T. (2019). Discriminating aggregate sources with in situ mineral
chemistry: an Irish example. Quarterly Journal of Engineering Geology and Hydrogeology, 53; 209-216.
Dornan, T., O’Sullivan, G., O’Riain, N., Stueeken, E. and Goodhue, R. (2020). The application of machine
learning methods to aggregate geochemistry predicts quarry source location: An example from Ireland.
Computers & Geosciences, 140, 104495.
El Aouidi, S., Said, F., Laissaoui, A., Ait Malek, O., Moncef, B., Elbatal, Y., Aadjour, M., Mounia, T., El
Yahyaoui, A., Benkdad, A. (2017). Geochemical Characterization of the Black Shale from the Ama Fatma
Coastal Site in the Southwest of Morocco. American Journal of Chemistry, 7(5): 153-162.
Erickson, B. E. and Helz, G. R. (2000). Molybdenum (VI) speciation in sulfidic waters: stability and lability
of thiomolybdates. Geochim. Cosmochim. Acta, 64: 1149-1158.
Gregory, D. D., Meffre, S. and Large, R. (2014). Comparison of metal enrichment in pyrite framboids from a
metal-enriched and metal-poor Estuary. American Mineralogist, Vol. 99 (4): 633–644.
Gallagher, M., Turner, E. C. and Kamber, B. S. (2015). In situ trace metal analysis of Neoarchaean–Ordovician
shallow-marine microbial-carbonate-hosted pyrites. Geobiology, 13: 316–339.
Gallego-Torres, D., Reolid, M., Nieto-Moreno, V. and Martínez-Casado, F. J. (2015). Pyrite framboid size
distribution as a record for relative variations in sedimentation rate: An example on the Toarcian Oceanic
Anoxic Event in Southiberian Palaeomargin. Sedimentary Geology 330: 59–73.
Ganje, T. J. (1966). Selenium. In Diagnostic Criteria for Plants and Soils. Chapman, H. D. Ed., University of
California, Division of Agricultural Science, pp. 394-404.
Goldberg, K. and Humayun, M. (2016). Geochemical paleoredox indicators in organic-rich shales of the Irati
Formation, Permian of the Paraná Basin, southern Brazil. Brazilian Journal of Geology, 46(3): 377-393.
Gomes, M. L. and Hurtgen, M. T. (2015). Sulfur isotope fractionation in modern euxinic systems: Implications
for paleoenvironmental reconstructions of paired sulfate–sulfide isotope records. Geochimica et
Cosmochimica Acta, Vol. 157: 39-55. ISSN 0016-7037, https://doi.org/10.1016/j.gca.2015.02.031
Grice, K., Schaeffer, P., Schwark, L. and Maxwell, J. R. (1997). Changes in palaeoenvironmental conditions
during deposition of the Permian Kupferschiefer (Lower Rhine Basin, northwest Germany) inferred from
molecular and isotopic compositions of biomarker components. Organic Geochemistry, Vol. 26, Issues 11–12: 677-690.
Hatch, J. R. and Leventhal, J. S. (1992). Relationship between inferred redox potential of the depositional
environment and geochemistry of the Upper Pennsylvanian (Missourian) Stark Shale Member of the
Dennis Limestone, Wabaunsee County, Kansas, U.S.A. Chemical Geology, 99(1–3): 65-82.
Hardisty, D., Lyons, T. W. and Riedinger, N. (2018). An evaluation of sedimentary molybdenum and iron as
proxies for pore fluid paleoredox conditions. American Journal of Science, 318(5): 527-556.
Hawkins, A. B. (2014). Engineering implications of the oxidation of pyrite: an overview,with particular
reference to Ireland. In: Hawkins, A. B. (Ed.), Implications of Pyrite Oxidation for Engineering Works.
Springer, Switzerland, pp. 1–98.
Helz, G. R., Miller, C. V., Charnock, J. M., Mosselmans, J. L. W., Pattrick, R. A. D., Garner, C. D. and
Vaughan, D. J. (1996). Mechanisms of molybdenum removal from the sea and its concentration in black
shales: EXAFS evidences. Geochim. Cosmochim. Acta, 60: 3631-3642.
Huerta-Diaz, M. A. and Morse, J. W. (1992). Pyritisation of trace metals in anoxic marine sediments.
Geochimica et Cosmochimica Acta, 56: 2681–2702.
Iida, Y., Tanaka, T., Yamaguchi, T. and Nakayama, S. (2011). Sorption Behavior of Selenium (-II) on Rocks
under Reducing Conditions. Journal of Nuclear Science and Technology, 48:2, 279-291.
Jiang, K., Zhou,W., Deng, N. and Song,W. (2020). Statistical analysis and significance of pyrite in the Wufenglower
Longmaxi shale formation in South China. Arab. Journal of Geoscience 13, No. 22, article no. 1181.
Jones, B. and Manning, D. A. C. (1994). Comparison of geochemical indices used for the interpretation of
palaeoredox conditions in ancient mudstones. Chemical Geology, 111(1-4): 111-129.
Khaustova, N., Tikhomirova, Y., Bastrakov, E., Korost, S., Poludetkina, E., Voropaev, A., Mironenko, M. and
Spasennykh, M. (2021). The Study of Uranium Accumulation in Marine Bottom Sediments: Effect of
Redox Conditions at the Time of Sedimentation. Geosciences, 11, 332. https://doi.org/10.3390/geosciences11080332
Koide, M., Hodge, V. F., Yang, J. S., Stallard, M., Goldberg, E. G., Calhoun, J. and Bertine, K. K. (1986).
Some comparative marine chemistries of rhenium, gold, silver and molybdenum. Applied Geochemistry, Vol. 1 (6): 705-714.
Kunert, A., Kendall, B., Moslow, T. F., Nyberg, G., Pedersen, B. and Smith, C. (2019): Preliminary
characterization of Early Jurassic source rocks and ocean-redox conditions based on trace-metal and
organic geochemistry of the Gordondale and Poker Chip Shale members, Fernie Formation, northeastern
British Columbia. In Geoscience BC Summary of Activities 2018: Energy and Water, Report No. 2019-2: 29-42.
Large, R. R., Halpin, J. A., Danyushevsky, L. V., Maslennikov, V. V., Bull, S. W., Long, J. A., Gregory, D.
D., Lounejeva, E., Lyons, T. W., Sack, P. J., McGoldrick, P. J. and Calver, C. R. (2014). Trace element
content of sedimentary pyrite as a new proxy for deep-time ocean–atmosphere evolution. Earth and
Planetary Science Letters, 389 209–220.
Lakin, H. W. and Davidson, D. F. (1967). The relation of the geochemistry of selenium to its occurrence in
soils. P. 27 in Selenium in Biomedicine: A Symposium, Muth, O. H., ed., Westport, Conn.
Liu, Z., Chen, D., Zhang, J., Lü, X., Wang, Z., Liao, W., Shi, X., Tang, J. and Xie, G. (2019). Pyrite Morphology
as an Indicator of Paleoredox Conditions and Shale Gas Content of the Longmaxi and Wufeng Shales in
the Middle Yangtze Area, South China. Minerals, 9, 428. https://doi.org/10.3390/min9070428
Łukawska-Matuszewska, K., Graca, B., Brocławik, O. and Zalewska, T.(2019). The impact of declining
oxygen conditions on pyrite accumulation in shelf sediments (Baltic Sea). Biogeochemistry, 142: 209-
230. https://doi.org/0.1007/s10533-018-0530-2
Maher, M. L. J. and Gray, C. (2014). Aggregates prone to causing pyrite-induced heave: How they can be
avoided. Pp. 58-66 in Hunger, E., Brown, T. J. and Lucas, G. (Eds.). Proceedings of the 17th Extractive
Industry Geology Conference, EIG Conferences Ltd. 202pp.
Marolf, N. J. (2014). Redox-Sensitive Trace Elements Document Chemical Depositional Environment and
Post-Depositional Oxidation of the Ediacaran Biri Formation, Southern Norway. Thesis submitted to
Colorado State University, 111 pages.
Matamoros-Veloza, A., Newton, R. J. and Benning, L. G. (2011). What controls selenium release during shale
weathering? Applied Geochemistry, 26: S222–S226.
McKay, J. L., Pedersen, T. F. and Mucci, A. (2007). Sedimentary redox conditions in continental margin
sediments (N.E. Pacific) — Influence on the accumulation of redox-sensitive trace metals. Chemical
Geology, Vol. 238, Issues 3–4: 180-196.
McLennan, S. M. (2001). Relationships between the trace element composition of sedimentary rocks and
upper continental crust. Geochemistry, Geophysics, Geosystems, 2, Art. no. 2000GC000109. https://doi.org/10.1029/2000GC000109
Merinero, R., Lunar, R., Martınez-Frıas, J., Somoza, L. and Dıaz-del-Rio, V. (2008). Iron oxyhydroxide and
sulphide mineralization in hydrocarbon seep-related carbonate submarine chimneys, Gulf of Cadiz (SW
Iberian Peninsula). Marine and Petroleum Geology, 25: 706–713.
Morford, J. L., Emerson S., Breckel, E. J. and Kim, S. H. (2005). Diagenesis of oxyanions (V, U, Re, and Mo)
in pore waters and sediments from a continental margin. Geochimica et Cosmochimica Acta, 69(21):5021-5032.
National Research Council (U.S.). (1983). Selenium in Nutrition: Revised Edition. Subcommittee on Selenium.
National Academies Press, Washington, DC, 174 p.
Nixon, P. J. (1978). Floor heave in buildings due to use of pyritic shales as fill materials. Chemistry and Industry, Vol. 4:160-164.
NSAI. (2012). Tests for Chemical properties of aggregates – Part 1: Chemical Analysis. I.S. EN 1744-
1:2009+A1:2012, National Standards Authority of Ireland, Dublin.
NSAI. (2013), Reactive pyrite in sub-floor hardcore material – Part 1: Testing and categorization protocol,
I.S. 398-1:2013, National Standards Authority of Ireland, Dublin.
NSAI. (2016). Code of Practice for the procurement and use of unbound granular fill hardcore material for
use under concrete floors. I.S. 888:2016, National Standards Authority of Ireland, Dublin.
NSAI. (2017), Reactive pyrite in sub-floor hardcore material – Part 1: Testing and categorization protocol,
I.S. 398-1:2017, National Standards Authority of Ireland, Dublin.
Penner E., Eden, W. J. and Grattan-Bellew, P. E. (1972). Expansion of Pyritic Shales, Canadian Building
Digest, Vol. 152, National Research Council of Canada, Ottawa.
Piper, D. Z. and Calvert, S. E. (2009). A marine biogeochemical perspective on black shale deposition. Earth-
Science Reviews, 95(1-2): 63–96.
Pourret, O. and Dia, A. (2016). Vanadium. W. M. White (ed.), Encyclopedia of Geochemistry. Springer, Cham.
Raiswell, R. and Canfield, D. E. (2012). The iron biogeochemical cycle past and present. Geochemical
Perspectives, vol. 1, No. 1, 232 pp.
Raiswell, R., Hardisty, D. S., Lyons, T. W., Canfield, D. E., Owens, J. D., Planavsky, N. J., Poulton, S. W. and
Reinhard, C. T. (2018). The Iron Paleoredox Proxies: A Guide to the Pitfalls, Problems and Proper
Practice. American Journal of Science, vol. 318, no. 5 491-526.
Rekharsky, V. I. (1973). В. И. Рехарский. Геохимия молибдена в эндогенных процессах. Москва, Наука
[Geochemistry of Molybdenum in endogenous processes]. Shipulin, F. K. (ed.). Nauka, Moscow.
RICS. (2015). The mundic problem, RICS Professional Guidance, UK, 3rd edition. Royal Institution of
Chartered Surveyors (RICS), London.
Rudnick, R. L. and Gao, S. (2003). The Composition of the Continental Crust. In Treatise on Geochemistry,
Volume 3, The Crust, Holland, H. D. and Turekian, K. K. (Eds.), Elsevier-Pergamon, Oxford, 1-64.
Ryskin, M. and Maher, M. L. J. (2021). The pyrite heave problem; new insights from trace-element analysis.
Géotechnique Letters, 11: 1-5.
Sawlowicz, Z. (1993). Pyrite framboids and their development: a new conceptual mechanism. Geologische
Rundschau, 82: 148-156.
Sawłowicz, Z. (2000) Framboids: from their origin to application. Prace Mineralogiczne (Mineralogical
Transactions) vol. 88, 80 pp.
Scholz, F., Siebert, C., Dale, A. W. and Frank, M. (2017). Intense molybdenum accumulation in sediments
underneath a nitrogenous water column and implications for the reconstruction of paleo-redox conditions
based on molybdenum isotopes, Geochimica et Cosmochimica Acta, Vol. 213: 400-417.
Scott, C. and Lyons, T. W. (2012). Contrasting molybdenum cycling and isotopic properties in euxinic versus
non-euxinic sediments and sedimentary rocks: refining the paleoproxies. Chemical Geology, 324: 19–27.
Sheen, A. I., Kendall, B., Reinhard, C. T., Creaser, R. A., Lyons, T. W., Bekker, A., Poulton, S. W. and Anbar,
A. D. (2018). A model for the oceanic mass balance of rhenium and implications for the extent of
Proterozoic ocean anoxia. Geochimica et Cosmochimica Acta, Vol. 227: 75-95.
Sims, I. and Santo, P. (2018). Managing the ‘Mundic’ Problem in South-West England. Workshop Proceedings
from a Nordic Workshop entitled, Impact of sulphide minerals (pyrrhotite) in concrete aggregate on
concrete behaviour, Nordic Concrete Federation, Oslo, Norway.
Taylor, S. R. and McLennan, S. M. (1985). The Continental Crust: Its Composition and Evolution. Blackwell
Scientific, Oxford, London, Edinburgh, Boston, Palo Alto and Melbourne, xvi + 312 pp. ISBN 0 632 01148 3.
Tribovillard, N., Algeo, T. J., Lyons, T. and Riboulleau, A. (2006). Trace metals as paleoredox and
paleoproductivity proxies: An update. Chemical Geology, 232(1-2):12-32.
Tribovillard, N., Lyons, T. W., Riboulleau, A. and Bout-Roumazeilles, V. (2008). A possible capture of
molybdenum during early diagenesis of dysoxic sediments. Bull. Soc. géol. Fr., t. 179, no 1: 3-12.
Tribovillard, N., Algeo, T. J., Baudin, F. and Riboulleau, A. (2012). Analysis of marine environmental
conditions based on molybdenum–uranium covariation – Applications to Mesozoic paleoceanography.
Chemical Geology, 324-325: 46–58.
Tribovillard, N., Hatema, E., Averbuch, O., Barbecot, F., Bout-Roumazeilles, V. and Trentesaux, A. (2015).
Iron availability as a dominant control on the primary composition and diagenetic overprint of organicmatter-
rich rocks. Chemical Geology, 401: 67–82.
Vorlicek, T. P., Kahn, M. D., Kasuya, Y. and Helz, G. R. (2004). Capture of molybdenum in pyrite-forming
sediments: Role of ligand-induced reduction by polysulfides. Geochimica et Cosmochimica Acta, Vol. 68, No. 3: 547–556.
Vorlicek, T. P., Helz, G. R., Chappaz, A., Vue, P., Vezina, A. and Hunter, W. (2018). Molybdenum Burial
Mechanism in Sulfidic Sediments: Iron-Sulfide Pathway. ACS Earth Space Chem., 2 (6): 565–576.
Walters, C. C. (2006). The Origin of Petroleum. In: Hsu, C. S. and Robinson, P. R. (eds) Practical Advances
in Petroleum Processing. Springer, New York, NY. https://doi.org/10.1007/978-0-387-25789-1_2
Wei, H., Algeo, T. J., Yu, H., Wang, J., Guo, C. and Shi, G. (2015). Episodic euxinia in the Changhsingian
(late Permian) of South China: Evidence from framboidal pyrite and geochemical data. Sedimentary Geology 319: 78–97.
Wignall, P. B., Bond, D. P. G., Kuwahara, K., Kakuwa, Y., Newton, R. J. and Poulton, S. W. (2010). An 80
million year oceanic redox history from Permian to Jurassic pelagic sediments of the Mino-Tamba terrane,
SW Japan, and the origin of four mass extinctions. Glob. Planet Change, 71, No. 1–2, 109–123.
Wu, T., Yang, R., Gao, L., Li, J. and Gao, J. (2021). Origin and Enrichment of Vanadium in the Lower
Cambrian Black Shales, South China. ACS Omega, 6 (41): 26870-26879 https://doi.org/10.1021/acsomega.1c02318
Yamanaka, T., Miyasaka, H., Aso, I., Tanigawa, M., Shoji, K. and Yohta, H. (2002). Involvement of Sulfurand
Iron-Transforming Bacteria in Heaving of House Foundations. Geomicrobiology Journal, 19:519–528.