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Overview

fossils
Teratological (malformed) and normal chitinozoans from core 14 in the A1-61 well. From Vandenbroucke et al., 2015, doi: 10.1038/ncomms8966.

Why is USGS interested in mass dependent Sr isotopic fractionation?

Over the last half century, the use of traditional radiogenic strontium (87/86Sr) has revolutionized our understanding of ore formation. The stable isotopic ratio of strontium (88Sr/86Sr), until very recently, was believed to be a universal constant and is routinely used for internal normalization to correct for instrumental mass bias. Recognition of mass-dependent strontium isotopic fractionation has opened a new frontier in isotope geochemistry.

Why is USGS conducting this research?

Our development of a double-spike Thermal Ionization Mass Spectrometry (TIMS) analytical method establishes the USGS as one of only a few labs in the world capable of measuring this chemical tracer (Neymark et al., 2014). We are the first to apply this nascent systematic to ore deposit studies. Our work on several ore-types in the U.S. midcontinent has already documented the largest range of δ88Sr measured on Earth and shows that paired δ88Sr-87/86Sr systematics have the potential to advance our understanding of the source and evolution of ore fluids, processes of ore deposition, and fluid migration pathways (Pelch et al., 2015; Emsbo et al., 2015). Moreover, this isotopic tool has the potential to allow determination of size of ore systems and to enable vectoring toward ore on a basin scale.

The δ88Sr compositions and processes that drive strontium fractionation in mineralizing systems are completely unknown. We are conducting an empirical baseline study to establish the δ88Sr compositions of different ore types.The midcontinent is an ideal laboratory within which to test the application of this new ore genesis tool because its ore deposits are well characterized, their geologic frameworks are well-established, and ore samples from most of these deposits have already been collected. Topical studies are being conducted for the following ore types:

  • Mississippi Valley Type (MVT) Deposits,
  • Sedimentary Copper Deposits,
  • Potash in Michigan Basin Salina Salt,
  • Volcanic-Hosted Massive Sulfide (VHMS) Deposits,
  • Phosphorite Rare Earth Element (REE) Deposits,
  • Iron Oxide Copper-Gold (IOCG) Deposits,
  • Magmatic Platinum-Group-Metals (PGM) deposits.

We have also developed and tested sampling/analytical methodologies to investigate the application of paired 87/86Sr - δ88Sr in chemostratigraphy that open exciting new assessment opportunities for sedex deposits. Moreover, during the development of our δ88Sr chemostratigrapic methods, we made potential discoveries that have implications for stratigraphy, paleontology, paleo- and evolutionary-biology.

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Publications - Journal Articles

Emsbo, Poul, 2017, Sedex brine expulsions to Paleozoic basins may have changed global marine 87Sr/86Sr values, triggered anoxia, and initiated mass extinctions: Ore Geology Reviews, 86, p. 474-486, Invited Review Article, doi:10.1016/j.oregeorev.2017.02.031.

Emsbo, P., McLaughlin, P.I., Breit, G.N., du Bray, E.A., and Koenig, A.E., 2015, Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?: Gondwana Research, 27(2), p. 776-785. doi:10.1016/j.gr.2014.10.008

Emsbo, P., McLaughlin, P.I., du Bray, E.A., Anderson, E.D., Vandenbroucke, T.R.A., and Zielinski, R.A., 2016, Rare earth elements in sedimentary phosphorite deposits: a global assessment: Reviews in Economic Geology 18, Society of Economic Geologists, p. 101-113.

Emsbo, Poul, Seal, R.R., Breit, G.N., Diehl, S.F., and Shah, A.K., 2016, Sedimentary exhalative (sedex) zinc-lead-silver deposit model: U.S. Geological Survey Scientific Investigations Report 2010–5070–N, 57 p., http://dx.doi.org/10.3133/sir20105070N.

Hofstra, A.H., Meighan, C.J., Song, X., Samson, I., Marsh, E.E., Lowers, H.A., Emsbo, P., and Hunt, A.G., 2016, Mineral thermometry and fluid inclusion studies of the Pea Ridge iron oxide-apatite–rare earth element deposit, Mesoproterozoic St. Francois Mountains terrane, southeast Missouri, USA: Economic Geology, 111(8), p. 1985-2016, https://doi.org/10.2113/econgeo.111.8.1985.

McLaughlin, P.I., Emsbo, P., Desrochers, A., Bancroft, A., Brett, C.E., Riva, J.F., Premo, W., Neymark, L., Achab, A., Asselin, E., and Emmons, M., 2016, Refining 2 km of Ordovician chronostratigraphy beneath Anticosti Island utilizing integrated chemostratigraphy: Canadian Journal of Earth Sciences, 53(8), p. 865-874, doi:10.1139/cjes-2015-0242.

Neymark, L.A., Premo, W.R., Mel'nikov, N.N., and Emsbo, P., 2014, Precise determination of δ88Sr in rocks, minerals, and waters by double-spike TIMS: a powerful tool in the study of geological, hydrological and biological processes: Journal of Analytical Atomic Spectrometry, 29, p. 65-75. doi: 10.1039/C3JA50310K

Pelch, M.A., Appold, M.S., Emsbo, P., and Bodnar, R.J., 2015, Constraints from fluid inclusion compositions on the origin of Mississippi Valley-Type mineralization in the Illinois-Kentucky district: Economic Geology, 110 (3), p. 787-808. doi: 10.2113/econgeo.110.3.787

Pribil, M.J., Ridley, W.I., and Emsbo, P., 2015, Sulfate and sulfide sulfur isotopes (δ34S and δ33S) measured by solution and laser ablation MC-ICP-MS: An enhanced approach using external correction: Chemical Geology, 412, p. 99-106, doi:10.1016/j.chemgeo.2015.07.014

Steeman, T., Vandenbroucke, T.R.A., Williams, M., Verniers, J., Perrier, V., Siveter, D.J., Wilkinson, J., Zalasiewicz, J. and Emsbo, P., 2016, Chitinozoan biostratigraphy of the Silurian Wenlock–Ludlow boundary succession of the Long Mountain, Powys, Wales: Geological Magazine, 153(1), p. 95-109, doi:10.1017/S0016756815000266

Sullivan, N.B., McLaughlin, P.I., Brett, C.E., Cramer, B.D., Kleffner, M.A., Thomka, J.R., and Emsbo, P., 2016, Sequence boundaries and chronostratigraphic gaps in the Llandovery of Ohio and Kentucky: The record of early Silurian paleoceanographic events in east-central North America: Geosphere, 12(6), p. 1813-1832, doi:10.1130/GES01343.1.

Sullivan, N.B., McLaughlin, P.I., Emsbo, P., Barrick, J.E., and Premo, W.R. 2016, Identification of the late Homerian Mulde Excursion at the base of the Salina Group (Michigan Basin, USA): Lethaia, 49(4), p. 591–603, doi:10.1111/let.12168.

Vandenbroucke, T.R.A., Emsbo, P., Munnecke, A., Nuns, N., Duponchel, L., Lepot, K., Quijada, M., Paris, F., Servais, T., and Kiessling, W., 2015, Metal-induced malformations in early Palaeozoic plankton are harbingers of mass extinction: Nature Communications, 6, Article Number 7966. doi:10.1038/ncomms8966

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Abstracts - Posters and Presentations

Brett, C.E., McLaughlin, P.I., Baird, G.C., Emsbo, P., Thomka, J.R., and Zambito, J., 2015, Silurian-Devonian environmental and biotic change recast in a new time scale: Evidence of changing volatility from the Appalachian basin: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 631. View Brett 2015 GSA abstract.

Brett, C.E., McLaughlin, P.I., Emsbo, P., Thomka, J.R. and Zambito, J.J., 2016, Mid-Paleozoic environmental stasis and volatility: driver of biotic macroevolution: International Geoscience Programme Project 591 - Closing Meeting, 6-9 July, 2016, Ghent, Belgium.

De Weirdt, J., Vandenbroucke, T.R.A., Emsbo, P., McLaughlin, P.I., Delabroye, A, Munnecke, A, and Desrochers, A., 2016, Testing global anoxia as an alternative cause for the Hirnantian mass extinction: new evidence from western Anticosti Island, Canada: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-280015.

Emsbo, P., 2017, Provocative observations from the Carlin trend: A case for unconventional thinking in ore genesis: Prospectors and Developers Association of Canada (PDAC), Volcanogenic and exhalative: A symposium dedicated to Richard W. Hutchinson, March 5-8, Toronto, Canada. View Emsbo 2017 PDAC abstract. [PDF file, 13 KB]

Emsbo, P., McLaughlin, P.I., Manning, A.H., Premo, W.R. Neymark, L.A., Brett, C.E., Vandenbroucke, T.R.A., Brunton, F.R., Barrick, J.E., Breit, G.N., Munnecke, A., and du Bray, E.A., 2016, Brines, metals, and bugs: The fate of the Palaeozoic world: International Geoscience Programme Project 591 - Closing Meeting, 6-9 July, 2016, Ghent, Belgium, p. 3. Keynote

Emsbo, P., McLaughlin, P.I., Manning, A.H., Premo, W.R. Neymark, L.A., Brett, C.E., Vandenbroucke, T.R.A., Brunton, F.R., Barrick, J.E., Breit, G.N., Munnecke, A., Emmons, M., and du Bray, E., 2016, Brine expulsions to Paleozoic basins: Trigger of catastrophic global change: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-286315.

Emsbo, P., McLaughlin, P.I., Vandenbroucke, T.R.A., du Bray, E., and Anderson, E.D., 2016. A global assessment of REE’s in sedimentary phosphate deposits: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-286523.

Hurth, M., McLaughlin, P., Emsbo, P., Brett, C.E., and Sell, B.K., 2013, Composite upper Ordovician chronostratigraphy in eastern North America—Developing a late Ordovician geochronologic reference standard of environmental records: Geological Society of America Abstracts with Programs, Vol. 45, No. 7, p. 747. View Hurth GSA abstract.

Johnson, C.A., Dumoulin, J.A., Bradley, D., and Emsbo, P., 2016, Sulfur, oxygen and carbon isotopes in the Gagaryah barite deposit, Farewell terrane, interior Alaska, and comparisons to the isotopic record of marine sulfur in Devonian time: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-283982.

Logan, L.A., Hofstra, A.H., Emsbo, P., 2016, Chemical and isotopic comparison of Illinois Basin brines and fluid inclusions in the Illinois-Kentucky Fluorspar District: Implications for the origin, paleohydrology, and preservation of Permian ore fluids Pan-American Current Research on Fluid Inclusions (PACROFI-XIII, University of Missouri-Columbia (USA), May 26–28, 2016, Abstract Volume.

Manning, A.H., and Emsbo, P., 2015, Numerical simulation of brine reflex systems and their potential role in mineral deposit formation: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 487. View Manning GSA abstract.

Mauk, J., and Emsbo, P., 2015, Genesis of sediment-hosted stratiform Cu deposits and geologic evolution of the North American Midcontinent rift: constraints from ore-forming brines from the White Pine deposit: 13th SGA Biennial Meeting, 24-27 August 2015, Nancy, France.

Mauk, J.L., Emsbo, P., and Theodorakos, P.M., 2015, Evaporated seawater formed sediment-hosted stratabound copper ore in the Midcontinent Rift: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 677. View Mauk 2015 GSA abstract.

Mauk, J., Emsbo, P., and Theodorakos, P., 2015, Evaporated seawater formed sediment-hosted stratiform copper orebodies and second-stage copper mineralization in the Mesoproterozoic Nonesuch Formation of the Midcontinent Rift: Proceedings of the 61st ILSG Annual Meeting - Part 1, p. 63-64. View 61st ILSG Proceedings [PDF file, 7.8 MB]

McLaughlin, P., Emsbo, P., Brett, C.E., Vandenbroucke, T., and Saltzman, M., 2015, Mass extinction and diachronism: Reconciling the end Ordovician rock record: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 65. View McLaughlin 2015 GSA abstract.

McLaughlin, P.I., Emsbo, P., Brett, C.E., Bancroft, A.M., Vandenbroucke, T.R.A., and Emmons, M., 2016, Multi-basin δ13Ccarb correlation of the Ireviken, Mulde and Lau excursions (eastern North America): a comprehensive sequence stratigraphic synthesis: International Geoscience Programme Project 591 - Closing Meeting, 6-9 July, 2016, Ghent, Belgium, p. 2.

McLaughlin, P.I., Brett, C.E., Emsbo, P., and Sell, B., 2014, Composite chronostratigraphy: pathway to comprehensive geochronology: GeoFrankfurt 2014, 21-24 September 2014, Frankfurt, Germany.

McLaughlin, P.I., Emsbo, P., Brett, C.E., 2015, The lithuanicus Event in the Michigan Basin: Rapid platform accretion in response to a perturbation of the mid-Telychian ocean-climate system: 5th International Symposium on the Silurian System and 5th Annual Meeting of IGCP 591, Quebec City, Canada, 3-20 July 2015, Abstract Volume (eds. M. Melchin and J. Jin), p. 30.

McLaughlin, P.I., Emsbo, P., Brett, C.E., Bancroft, A.M., and Vandenbroucke, T.R.A., 2016, Multi-basin carbon isotope correlation of the Ireviken, Mulde and Lau excursions (eastern north America): A comprehensive sequence stratigraphic synthesis: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-284577.

McLaughlin, P., Emsbo, P., Brett, C., Hurth, M., Sell, B., and Johnson, C., 2014, Testing the limits of high-resolution whole-rock 13Ccarb stratigraphy: AGU Fall Meeting, 15-19 December 2015, San Francisco, CA. View McLaughlin AGU abstract.

McLaughlin, P.I., Emsbo, P., Desrochers, A., Premo, W., Neymark, L., Brett, C.E., 2015, Interpreting two kilometers of Ordovician chemostratigraphy beneath Anticosti Island: 5th International Symposium on the Silurian System and 5th Annual Meeting of IGCP 59, Quebec City, Canada, 3-20 July 2015, Abstract Volume (eds. M. Melchin and J. Jin), p. 31.

Meighan, C.J., Hofstra, A.H., Marsh, E.E., Lowers, H.A., Emsbo, P., and Hitzman, M.W., 2014, Generation of monazite and other REE-bearing phases by secondary fluid events, Pea Ridge iron oxide-apatite-REE deposit, Southeast Missouri, USA: Abstract Volume, Pan-American Current Research on Fluid Inclusions (PACROFI XII), Denver and Pingree Park, Colorado, 2 p.

Munnecke, A., Jarochowska, E., Männik, P., Vandenbroucke, T. R. A., Hints, O., Hartinger, N., Lehnert, O., Huff, W., Kozłowski, W., and Emsbo, P., 2014, Lower Telychian ironstone deposits in the Podlasie Basin, NE Poland: δ13C and conodont stratigraphy: 4th Annual Meeting of IGCP 591 ‘The Early to Middle Paleozoic Revolution’, Estonia, Abstracts and Field Guide, p. 97.

Scott, R., Emsbo, P., and Goemann, K., 2015, Still Stuck in the Mud: Reevaluation of Stratiform Gold in the Upper Popovich Formation, Northern Carlin Trend, Nevada: Society of Economic Geologists 2015 Annual Conference Proceedings, 27-30 September 2015, Hobart, TAS, Australia. View Scott SEG abstract. [PDF file, 118 KB]

Steeman, T., Vandenbroucke, T.R.A., Williams, M., Verniers, J., Perrier, V., Siveter, D.J., Wilkinson, J., Zalasiewicz, J., and Emsbo, P., 2016, Chitinozoan biostratigraphy through the Silurian Wenlock–Ludlow boundary succession of the Long Mountain (Powys, Wales): International Geoscience Programme Project 591 - Closing Meeting, 6-9 July, 2016, Ghent, Belgium, p. 10.

Sullivan, N., McLaughlin, P.I., Emsbo, P., and Barrick, J.E., 2014, Integrated conodont biostratigraphy and chemostratigraphy (δ13Ccarb, 87Sr/86Sr, major and trace elements) of the Waubakee Formation (upper Silurian) in eastern Wisconsin: A new approach to an unresolved chronostratigraphic problem: Geological Society of America Abstracts with Programs, Vol. 46, No. 6, p. 755. View Sullivan 2014 GSA abstract.

Vandenbroucke, T.R.A., Emsbo, P., and Munnecke, A. 2014, Death metal in the early Paleozoic: Geological Society of America Abstracts with Programs, Vol. 46, No. 6, p. 399. View Vandenbroucke 2014 GSA abstract.

Vandenbroucke, T.R.A., Emsbo, P., and Munnecke, A., 2014, 'Death Metal' in the Early Palaeozoic: Programme and abstracts for the 58th Annual Meeting of the Palaeontological Association,16-19 December 2007, Leeds, UK, p. 50.

Vandenbroucke, T.R.A., Emsbo, P., Munnecke, A. and Quijada, M., 2015, Harbingers of Silurian Extinction: 5th International Symposium on the Silurian System and 5th Annual Meeting of IGCP 59, Quebec City, Canada, 3-20 July 2015, Abstract Volume (eds. M. Melchin and J. Jin), p. 54.

Vandenbroucke, T.R.A., Hylebos, A., Pohl, A., Sadler, P., Donnadieu Y., Le Hir, G., Sabbe, K., Williams, M., Ghienne, J., De Weirdt, J., McLaughlin, P.I., and Emsbo, P., 2016, Further evidence for a long-lived Ordovician icehouse climate suggests alternative kill mechanisms for the end-Ordovician mass extinctions: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-279962.

Vandenbroucke, T.R.A., Rohrssen, M., Munnecke, A., Hints, O., Love, G.D., Fischer, W.W. and Emsbo, P., 2014, Reconstructing the environmental conditions around the Silurian Ireviken Event combining the carbon isotope composition of bulk and palynomorph organic matter and biomarker data: 4th Annual Meeting of IGCP 591 ‘The Early to Middle Paleozoic Revolution’, Estonia, Abstracts and Field Guide, p. 66.

Velleman, J.F.M., Vandenbroucke, T.R.A., and McLaughlin, P., 2016, Building a chitinozoan biostratigraphy to anchor Upper Ordovician chemostratigraphy in the Cincinatti Arch (USA): International Geoscience Programme Project 591 - Closing Meeting, 6-9 July, 2016, Ghent, Belgium.

Zambito IV, J., Mclaughlin, P.I., Haas, L.D., and Emsbo, P., 2016, PXRF signatures of the Cambrian SPICE event in nearshore depositional settings of the Wisconsin Arch: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-285479.

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