Steven B Shirey

 
 

Diamonds and the inclusions that they host as well as eclogites and peridotites can be used to study the evolution of the continental lithospheric mantle. Recent advances come from the application of the naturally occurring beta decay of 187-rhenium to 187-osmium to these rocks and minerals, a technique which was pioneered at the Carnegie Institution. Studies such as these are the perhaps the best direct probe we have of ancient continental tectonics at mantle depths.

Smit, K.V., Shirey, S.B., Richardson, S.H., Le Roex, A.P., and Gurney, J.J., 2010, Re–Os isotopic composition of peridotitic sulphide inclusions in diamonds from Ellendale, Australia: Age constraints on Kimberley cratonic lithosphere: Geochimica et Cosmochimica Acta, v. 74, p. 3292-3306.

Janney, P., Shirey, S., Carlson, R., Pearson, D., Bell, D., Le Roex, A., Ishikawa, A., Nixon, P., and Boyd, F., 2010, Age, Composition and Thermal Characteristics of South African Off-Craton Mantle Lithosphere: Evidence for a Multi-Stage History: Journal of Petrology, v. 0, p. 1-42.

Gurney, J., Helmstaedt, H., Richardson, S., and Shirey, S., 2010, Diamonds through Time: Economic Geology, v. 105, p. 689.

Richardson, S., Pöml, P., Shirey, S., and Harris, J., 2009, Age and origin of peridotitic diamonds from Venetia, Limpopo Belt, Kaapvaal-Zimbabwe Craton: Lithos, v. 112, p. 785-792.

Aulbach, S., Stachel, T., Creaser, R.A., Heaman, L.M., Shirey, S.B., Muehlenbachs, K., Eichenberg, D., and Harris, J., 2009, Sulphide survival and diamond genesis during formation and evolution of Archaean subcontinental lithosphere: A comparison between the Slave and Kaapvaal cratons: Lithos, v. 112, p. 747-757.

Aulbach, S., Shirey, S.B., Stachel, T., Creighton, S., Muehlenbach, K., and Harris, J.W., 2009, Diamond formation episodes at the southern margin of the Kaapvaal Craton: Re-Os systematics of sulfide inclusions from the Jagersfontein Mine: Contributions to Mineralogy and Petrology, v. 157, p. 525-540.

Richardson, S.H., and Shirey, S.B., 2008, Continental mantle signature of Bushveld magmas and coeval diamonds: Nature, v. 453, p. 910-913.

Westerlund, K.J., Shirey, S.B., Richardson, S.H., Carlson, R.W., Gurney, J.J., and Harris, J.W., 2006, A subduction origin for Early Archean peridotitic diamonds and harzburgites from the Panda kimberlite, Slave craton: Implications from Re-Os isotope systematics: Contributions to Mineralogy and Petrology, v. 152, p. 275-294.

Ionov, D.A., Shirey, S.B., Weis, D., and Brugmann, G., 2006, Os-Hf-Sr-Nd isotope and PGE systematics of spinel peridotite xenoliths from Tok, SE Siberian craton: Effects of pervasive metasomatism in shallow refractory mantle: Earth and Planetary Science Letters, v. 241, p. 47-64.

Westerlund, K.J., Gurney, J.J., Carlson, R.W., Shirey, S.B., Hauri, E.H., and Richardson, S.H., 2004, A metasomatic origin for late Archaean eclogitic diamonds: Implications from internal morphology of Klipspringer diamonds and Re-Os and S isotope characteristics of their sulfide inclusions: South African Journal of Geology, v. 107, p. 119-130.

Shirey, S.B., Richardson Stephen, H., and Harris, J.W., 2004, Integrated models of diamond formation and craton evolution: Lithos, v. 77, p. 923-944.

Shirey, S.B., Richardson, S.H., and Harris, J.W., 2004, Age, paragenesis, and composition of diamonds and evolution of the Precambrian mantle lithosphere of southern Africa: South African Journal Geology, v. 107, p. 91-106.

Richardson, S.H., Shirey, S.B., and Harris, J.W., 2004, Episodic diamond genesis at Jwaneng, Botswana, and implications for Kaapvaal craton evolution: Lithos, v. 77, p. 143-154.

Shirey, S.B., Harris, J.W., Richardson, S.H., Fouch, M.J., James, D.E., Cartigny, P., Deines, P., and Viljoen, F., 2003, Regional patterns in the paragenesis and age of inclusions in diamond, diamond composition and the lithospheric seismic structure of southern Africa: Lithos, v. 71, p. 243-258.

Pearson, D.G., Canil, D., and Shirey, S.B., 2003, Chapter 7 - Mantle samples included in volcanic rocks: xenoliths and diamonds, in Carlson, R.W., ed., Teatise On Geochemistry: Vol. 2, The Mantle: New York, Elsevier, p. 171-277.

Menzies, A.H., Carlson, R.W., Shirey, S.B., and Gurney, J.J., 2003, Re-Os Systematics of Diamond-bearing Eclogites from Newlands Kimberlite: Lithos, v. 71, p. 323-336.

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, v. 297, p. 1683-1686.

Shirey, S.B., Carlson, R.W., Richardson, S.H., Menzies, A., Gurney, J.J., Pearson, D.G., Harris, J.W., and Wiechert, U., 2001, Archean emplacement of eclogitic components into the lithospheric mantle during formation of the Kaapvaal Craton: Geophysical Research Letters, v. 28, p. 2509-2512.

Richardson, S.H., Shirey, S.B., Harris, J.W., and Carlson, R.W., 2001, Archean subduction recorded by Re-Os isotopes in eclogitic sulfide inclusions in Kimberley diamonds: Earth and Planetary Science Letters, v. 191, p. 257-266.

Carlson, R.W., Boyd, F.R., Shirey, S.B., Janney, P.E., Grove, T.J., Bowring, S.A., Schmitz, M.D., Dann, J.C., Bell, D.R., Gurney, J.J., Richardson, S.H., Tredoux, M., Menzies, A.H., Pearson, D.G., Hart, R.J., Wilson, A.H., and Moser, D., 2000, Continental growth, preservation, and modification in Southern Africa: GSA Today, v. 10, p. 1-7.

Shirey, S.B., 1999, Waldemar Lindgren Award for 1999 - Citation of David Graham Pearson: Economic Geology and the Bulletin of the Society of Economic Geologists, v. 94, p. 1389-1390.

Pearson, D.G., Shirey, S.B., Bulanova, G.P., Carlson, R.W., and Milledge, H.J., 1999, Re-Os isotope measurements of single sulfide inclusions in a Siberian diamond and its nitrogen aggregation systematics: Geochimica et Cosmochimica Acta, v. 63, p. 703-711.

—, 1999, Dating and paragenetic distinction of diamonds using the Re-Os isotope system; application to some Siberian diamonds, in Gurney John, J., Gurney James, L., Pascoe Michelle, D., and Richardson Stephen, H., eds., The P. H. Nixon Volume: Proceedings of the International Kimberlite Conference. 7, Vol: Cape Town, Red Roof Design, p. 637-643.

Pearson, D.G., and Shirey, S.B., 1999, Isotopic dating of diamonds, in Lambert David, D., and Ruiz, J., eds., Application of radiogenic isotopes to ore deposit research and exploration., Volume 12: Reviews in Economic Geology: Boulder, CO, United States, Society of Economic Geologists, p. 143-171.

Menzies, A.H., Carlson, R.W., Shirey, S.B., and Gurney, J.J., 1999, Re-Os systematics of Newlands peridotite xenoliths; implications for diamond and lithosphere formation, in Gurney, J.J., Gurney, J.L., Pascoe, M.D., and Richardson, S.H., eds., The P. H. Nixon Volume: Proceedings of the International Kimberlite Conference. 7, Vol: Cape Town, Red Roof Design, p. 566-573.

Carlson, R.W., Pearson, D.G., Boyd, F.R., Shirey, S.B., Irvine, G., Menzies, A.H., and Gurney, J.J., 1999, Re-Os systematics of lithosphere peridotites; implications for lithosphere formation and preservation, in Gurney, J.J., Gurney, J.L., Pascoe, M.D., and Richardson, S.H., eds., The J. B. Dawson Volume: Proceedings of the International Kimberlite Conference. 7, Vol: Cape Town, Red Roof Design, p. 99-108.

Shirey, S.B., and Walker, R.J., 1998, The Re-Os isotope system in cosmochemistry and high-temperature geochemistry: Annual Review of Earth and Planetary Sciences, v. 26, p. 423-500.

Pearson, D.G., Shirey, S.B., Harris, J.W., and Carlson, R.W., 1998, Sulphide inclusions in diamonds from the Koffiefontein kimberlite, S Africa; constraints on diamond ages and mantle Re-Os systematics: Earth and Planetary Science Letters, v. 160, p. 311-326.

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, v. 374, p. 711-713.

Pearson, D.G., Shirey, S.B., Carlson, R.W., Boyd, F.R., Pokhilenko, N.P., and Shimizu, N., 1995, Re-Os, Sm-Nd, and Rb-Sr isotope evidence for thick Archaean lithospheric mantle beneath the Silurian craton modified by multistage metasomatism: Geochimica et Cosmochimica Acta, v. 59, p. 959-977.

Pearson, D.G., Carlson, R.W., Shirey, S.B., Boyd, F.R., and Nixon, P.H., 1995, Stabilisation of Archaean lithospheric mantle; a Re-Os isotope study of peridotite xenoliths from the Kaapvaal Craton: Earth and Planetary Science Letters, v. 134, p. 341-357.

Relevant Publications

Sketch map of the Kaapvaal-Zimbabwe craton showing the position of key tectonic, magmatic and mantle keel components in relation to the age and isotopic grouping of diamond inclusions. The craton boundary is shown in black, the suture between its two halves in black with teeth, marginal subduction in brown with teeth. Symbols show diamond mines where a population of multiple sulfide inclusions were studied. From Shirey, CIW Yearbook 2009-2010.

Most of this work involved specimens from the Kaapvaal craton but we have been able to carry out work on the Siberian craton, Russia, the Slave craton, Canada and the Kimberley Block, Australia.

Our diamond work to date has led to these accomplishments: 1) being able to synthesize diamond formation with mantle lithosphere age, seismic structure, and major crustal assembly events (see below); 2) the dating of the oldest (3.52 Ga) diamond suite and establishment of its subduction origin; 3) recognizing that craton margin reactivation is important to the production of Proterozoic, eclogitic diamonds; 4) estimating the interaction of Bushveld magmas with the lithosphere at 150 km depths; 5) relating differences in cratonic fertility to diamond paragenesis; and 6) recognition that craton amalgamation and reworking controls patterns of sulfide-bearing diamond distribution (see below).

Tomographic image of the lithospheric mantle derived from seismic P-wave data at a depth of 150 km (2, 3). The color scheme depicts % deviation from an average cratonic lithosphere velocity model. Coverage spans the lithospheric mantle of the Kaapvaal (K) and Zimbabwe (Z) cratons and the and Limpopo mobile belt (L; see inset, left). Bold green line indicates the outermost boundary of the Archean cratons as defined by a sharp break between Archean and Proterozoic Re-Os ages on peridotite xenoliths. The location of diamond mines are shown by colored squares. Red squares are localities whose silicate inclusion in diamond suites are predominately eclogitic (Jagersfontein, JA; Jwaneng, JW; Letlhakane,LE; Orapa, O; Premier , P) and green squares are localities whose silicate inclusion suites are predominately peridotitic  (Kimberley area mines of Bultfontein, De Beers, DuToitspan, and Wesselton termed DeBeers Pool, D;  Finsch, F; Koffiefontein, KO; Roberts Victor ,R; and Venetia, V). Mines located above red-yellowish areas referred to in text as having diamonds derived from seismically slower mantle; mines located above greenish-blue areas referred to in text as having diamonds derived from seismically faster mantle. From Shirey et al., Science 2002

Kaapvaal Craton: occurrence of diamond type controlled by craton assembly

Kimberley Block: Proterozoic reactivation of Archean lithospheric mantle

(A) Re–Os isotopic compositions of the eclogitic and peridotitic sulphide inclusions. Also shown is the lherzolitic regression and its error envelope, extrapolated to radiogenic Os isotopic compositions, as well as reference age arrays for the Yampi and King Leopold Orogenies. (B) Regression analysis of the peridotitic sulphides. The preferred regression through the six sulphides that show the best linearity (excluding EL55_2) is shown as a solid line, with its error envelope as dotted lines. A regression through all the sulphide inclusions is shown as a dashed line. 2r error b. From Smit et al., GCA 2010.

Tomographic images of the seismic S wave velocity anomalies at 150 km and 200 km depths beneath the Australian region (Fishwick et al., 2005) and sketch map of the Australian continent outlining the Archaean cratons and orogens (Li, 2000, after Myers et al. (1996)). The locations of Ellendale (E) in the King Leopold Orogen and Argyle (A) in the Halls Creek Orogen are indicated. From Smit et al., GCA 2010.

Silicate inclusion paragenesis (peridotitic or eclogitic; upper left) of inclusion-bearing Kaapvaal diamonds shows a correspondence with the current tomographic structure of the cratonic root  showing that largely Proterozoic diamonds have grown in equilbrium with portions of the mantle affected by 2.05 Ga Bushveld magmatism. On the other hand, sulfide inclusion age and paragenesis (upper right) of sulfide-bearing Kaapvaal diamonds are a product of Archean cratonic block assembly and the slab-underthrusting that preferentailly affected the Kimberley block relative to the Wits Block (lower right).

Recent work by predoctoral fellow Karen V Smit (now a PhD candidate, University of Alberta) provides a good example of how diamonds can track evolution of Archean lithospheric mantle. Peridotitic sulfides in diamonds from the 20 million year old Ellendale lamproite (E, above) in the King Leopold orogen on the western side of the Kimberley Block, northern Australia (above) give a 1426 million year old Re-Os isochron, matching the age of Argyle (A, above) diamonds and extending this Proterozoic diamond formation event. Their low initial 187Os/188Os (0.104) is a clue that they have formed in reactivated Archean mantle with a model age greater than 3 billion years.

A rough dodecahedral diamond from Orapa, Botswana displaying a prominent sulfide inclusion. The inclusion is the small grain at the very center of the dark triangular patch. A 1 mm wafer will be cut through this diamond to enclose the inclusion. The wafer will be polished, imaged for growth zoning by CL, ion probed for C and N isotopic composition, and then cleaved to remove the inclusion.  Once the inclusion has been cleaved out, it will imaged on the SEM, then dissolved for Re and Os isotopic analysis from which its radiometric age can be calculated. An SEM image of a larger inclusion from another diamond released in such a manner is shown in the inset. Field of view in larger image is ~3mm. Field of view in inset is about 100 microns.

Summary of tectonic evolution and diamond formation in the Kaapvaal Craton (based on de Wit et al., 1992; Shirey et al. 2004; Griffin et al., 2004; Aulbach et al., in revision). A Oceanic plateau/continental nuclei formation, extrusion of Barberton komatiites at excess mantle temperatures (plume), large melting intervals and attendant sulfide exhaustion, diamond-unfriendly conditions (?heat); B Metasomatic silicate-included diamond formation (Kaapvaal; Richardson et al., 1984), amalgamation (Witwatersrand); C Lithosphere accretion and thickening (craton amalgamation) and associated eclogitic sulfide-included diamond formation (Richardson et al., 2001, 2004; Shirey et al., this volume), metasomatic peridotitic sulfide  introduction (no diamond formation); D Remobilisation of eclogitic components and associated sulfide-included diamond formation, continued metasomatic peridotitic sulfide  addition; E Metasomatic peridotitic sulfide addition and minor associated sulfide-included diamond-formation (Pearson et al., 1998; Aulbach et al., 2009).