Nature, Science, Science Advances & Geology Articles

23 articles in Geology, Nature, Science, & Science Advances (1980-2021)

Smith, E.M., Peng, N., Shirey, S.B., Richardson, SH., Wang, W., and Shahar, A. (2021) Heavy iron in large gem diamonds traces deep subduction of serpentinized ocean floor. Science Advances 7: eabe9773 https://doi.org/10.1126/sciadv.abe9773

Importance: The heavy iron isotopic composition of metallic inclusions in sublithospheric diamonds rules out disproportionation (the hitherto expected mechanism to explain the occurrence of metal) and suggests instead that the iron is derived from magnetite that is produced during the low-temperature serpentinization of sea-floor peridotite. The iron isotope composition of iron inclusions in diamonds is thus one of the best tracers of deep subduction and recycling of Earth's surficial components.

Smit, K.V., Shirey, S.B., Hauri, E.H., and Stern, R.A. (2019) Sulfur isotopes in diamonds reveal differences in continent construction. Science 364, 383-385. http://doi.org/10.1126/science.aaw9548

Importance: Mass independently fractionated (MIF) sulfur isotopes show that Neoarchean and younger subcontinental lithospheric mantle is stabilized by lateral accretion of oceanic lithosphere and advective thickening.

Smith, E. M., Shirey, S. B., Richardson S. H., Nestola, F., Bullock, E. S., Wang, J., & Wang, W. (2018). Blue boron-bearing diamonds from Earth’s lower mantle. Nature 560, 84–87. http://doi.org/10.1038/s41586-018-0334-5

Importance: For the first time, blue diamonds are shown to be among the deepest diamonds ever found. A suite of 46 blue diamonds all have mineral assemblages retrograded from lower mantle and/or mantle transition zone mineralogies. This suggests that the boron in these diamonds is recycled from altered ocean floor serpentinite into very deep mantle depths.

Smith, E. M., Shirey, S. B., Nestola, F., Bullock, E. S., Wang, J., Richardson S. H., & Wang, W. (2016). Large gem diamonds from metallic liquid in Earth’s deep mantle. Science, 354, 1403–1405. http://doi.org/10.1126/science.aal1303

Importance: Confirmation that iron metal exists in the mantle transition zone and that regions of the mantle are highly reduced. This is the first evidence for how the world's biggest gem diamonds form.

Steele A., McCubbin F.M., Fries M., Kater L., Boctor N.Z., Fogel M.L., Conrad P.G., Glamoclija M., Spencer M., Morrow A.L., Hammond M.R., Zare R.N., Vicenzi E., Siljstrom S., Bowden R., Herd C.D.K., Mysen B.O., Shirey S.B., Amundsen H.E.F., and Treiman A.H. T. (2012) A reduced organic carbon component in Martian basalts. Science, 337, 212-215. https://doi.org/10.1126/science.1220715

Importance: An igneous source for early Martian carbon shows it could be abiotic thereby setting a valid background for the detection of biotic carbon on Mars.

Walter, M. J., Kohn, S. C., Araujo, D., Bulanova, G. P., Smith, C. B., Gaillou, E., et al. (2011). Deep Mantle Cycling of Oceanic Crust: Evidence from Diamonds and Their Mineral Inclusions. Science, 334, 54–57. http://doi.org/10.1126/science.1209300

Importance: Direct mineralogical evidence for recycling of oceanic basalt into the mantle transition zone, a process widely imaged by seismic tomography was found in this suite of inclusions from the area Juina, Brazil area.

Shirey, S. B., & Richardson, S. H. (2011). Start of the Wilson Cycle at 3 Ga Shown by Diamonds from Subcontinental Mantle. Science, 333, 434–436. http://doi.org/10.1126/science.1206275

Importance: A systematic change in the mineralogy of all inclusions in diamond analyzed for geochronology (>4000 individual diamonds) pinpoints the onset of plate tectonics around 3.2 Ga. At this time, eclogitic materials begin to appear as part of the continental lithospheric mantle suggesting oceanic slabs were subducted to mantle depths.

Richardson S. H. & Shirey, S. B. (2008). Continental mantle signature of Bushveld magmas and coeval diamonds. Nature, 453, 910–913. http://doi.org/10.1038/nature07073

Importance: An association is made between the Sr, Nd, and Os isotopic composition of 2 Ga diamonds and Bushveld Intrusion magmas showing a continental mantle imprint on the Bushveld magma compositions.

Wilson, A.H., Shirey, S.B., and Carlson, R.W., 2003, Archean ultra-depleted komatiites formed by hydrous melting of cratonic mantle: Nature, 423, 858-861. http://dx.doi.org/10.1038/nature01701

Importance: One of the world's oldest komatiites has an ultradepleted composition that is siliceous enough to be generated by hydrous melting.

Hart, G.L., Johnson, C.M., Hildreth, W., and Shirey, S.B., 2003, New Os isotope constraints on intra-crustal recycling of crustal domains with discrete ages: Geology, 31, 427-430. http://dx.doi.org/10.1130/0091-7613(2003)031%3C0427:NOIEFI%3E2.0.CO%3B2.

Importance: Os isotope compositions provide new constraints on amounts of intracrustal recycling in young subduction-zone environments that reflect the magmatic history of the arc. Sr, Nd, Hf, and Pb isotope variations in this young, mafic arc complex are too small to allow such constraints to be seen but they are evident using Os isotopes.

Shirey, S.B., Harris, J.W., Richardson, S.H., Fouch, M.J., James, D.E., Cartigny, P., Deines, P., and Viljoen, F., 2002, Diamond genesis, seismic structure, and evolution of the Kaapvaal-Zimbabwe craton: Science, 297, 1683-1686. http://dx.doi.org/10.1126/science.1072384

Importance: This paper makes the first regional correlation between diamond paragenesis (eclogitic versus peridotitic) and refertilization of the continental mantle keel (as evidenced by slow seismic velocity at 150 km depths) during the Bushveld magmatic event.

Tredoux, M., Hart, R.J., Carlson, R.W., and Shirey, S.B., 1999, Ultramafic rocks at the center of the Vredefort structure: Further evidence for the crust on edge model: Geology, 27, 923-926. http://dx.doi.org/10.1130/0091-7613(1999)027<0923:URATCO>2.3.CO;2

Importance: Re-Os data on ultramafic rocks at the center of the Vredefort impact structure --the world's largest such impact-- show Os model ages equivalent to old depleted mantle thus proving that the core of the structure is made up of continental lithospheric mantle on edge and not related to Bushveld magmatism.

Esperança, S., Carlson, R. W., Shirey, S. B., & Smith, D. (1997). Dating crust-mantle separation: Re-Os isotopic study of mafic xenoliths from central Arizona. Geology, 25, 651–654. http://doi.org/10.1130/0091-7613(1997)025<0651:DCMSRO>2.3.CO;2

Brandon, A. D., Creaser, R. A., Shirey, S. B., & Carlson, R. W. (1996). Osmium Recycling in Subduction Zones. Science, 272, 861–864. http://doi.org/10.1126/science.272.5263.861

Importance: Using a combination of Nd and Os on arc xenoliths, the mobility of Os and resultant enrichment in 187Os/188Os under relatively oxidizing conditions of the arc wedge is documented for the first time.

Koeberl, C., Reimold, W.U., and Shirey, S.B., 1996, Re-Os isotope and geochemical study of the Vredefort Granophyre; clues to the origin of the Vredefort Structure, South Africa: Geology, 24, 913-916. 10.1130/0091-7613(1996)024<0913:ROIAGS>2.3.CO;2

Pearson, D.G., Snyder, G.A., Shirey, S.B., Taylor, L.A., Carlson, R.W., and Sobolev, N.V., 1995, Archaean Re-Os age for Siberian eclogites and constraints on Archaean tectonics: Nature, 374, 711-713. http://doi.org/10.1038/374711a0

Importance: The first Re-Os isochron on eclogite xenoliths from the subcontinental lithospheric mantle of Siberia shows conclusively that they are Archean in age and therefore probably pieces of subducted Archean oceanic crust.

Lambert, D.D., Shirey, S.B., and Bergman, S.C., 1995, Proterozoic lithospheric mantle source for the Prairie Creek lamproites; Re-Os and Sm-Nd isotopic evidence: Geology, 23, 273-276. http://doi.org/10.1130/0091-7613(1995)023<0273:PLMSFT>2.3.CO;2

Koeberl, C., & Shirey, S. B. (1993). Detection of a Meteoritic Component in Ivory Coast Tektites with Rhenium-Osmium Isotopes. Science, 261, 595–598. http://doi.org/10.1126/science.261.5121.595

Ellam, R. M., Carlson, R. W., & Shirey, S. B. (1992). Evidence From Re-Os Isotopes for Plume Lithosphere Mixing in Karoo Flood-Basalt Genesis. Nature, 359, 718–721. http://doi.org/10.1038/359718a0

Lambert, D. D., Morgan, J. W., Walker, R. J., Shirey, S. B., Carlson, R. W., Zientek, M. L., & Koski, M. S. (1989). Rhenium-Osmium and Samarium-Neodymium Isotopic Systematics of the Stillwater Complex. Science, 244, 1169–1174. http://doi.org/10.1126/science.244.4909.1169

Shirey, S. B., Bender, J. F., & Langmuir, C. H. (1987). Three-component isotopic heterogeneity near the Oceanographer transform, Mid-Atlantic Ridge. Nature, 325, 217–223. https://www.nature.com/articles/325217a0.pdf

Shirey, S.B., and Hanson, G.N., 1984, Mantle-derived Archaean monzodiorites and trachyandesites: Nature, 310, 222-224. http://www.nature.com/articles/Art310222a0.pdf

Shirey, S. B., Simmons, G., & Padovani, E. R. (1980). Angular, Oriented Microtubes in Metamorphic Plagioclase. Geology, 8, 240–244. http://doi.org/10.1130/0091.7613