Short course "Diamond as a messenger from the Earth's interior: natural samples and experiment Part Diamond: properties, occurrence, methods of study _ f Yana Fedortchouk Department of Earth Sciences, Dalhousie University Halifax, Canada (yana@dal.ca) C UNIVERSITY Inspiring Minds Outline • Why do we study diamonds? What makes it a unique mineral? • age, occurrence, properties • Where do we find diamonds? • Primary sources (kimberlites, lamproites) and placers • Unconventional diamond sources • Ultra-high pressure metamorphic rocks • What can we learn from diamonds? • Review of diamond properties and modern analytical techniques used in diamond studies • Composition (impurities) - nitrogen • Carbon and nitrogen isotopes • Inclusions: mineral and fluid • Age dating Why do we study diamonds? What makes it a unique mineral? Eon ü 'O N o & o 0- ro o < c ro ra x Era Age iM.li Sedimentary Kimberlite Lamproite UML UCS UHP Host Rocks GI Gil Cenozoic Mesozoic Paleozoic Neo-proterozoic Meso-proterozoic Paleo-proterozoic Neoarchean Meso-archean Paleo-archean Eoarchean ■ 65 -250-■542 s_ a -3K a 110 ♦I 20fT El Dl E Dl P ♦ IP- 1200 Es Ro 0 Bi -2200 yBa ♦ ■-Ar ♦ ■l-Bo -1400 Ku . Tw 2188 Wdwa 4- Wa Ak Bi Diamond □a inclusions u Oil _o O -1-Da -2200 IWa 2750 oWR witwatersrand Supergroup containing I Lher;:olitic 3200 JHC oldest macrodiamonds Jack Hills conglomerate, with microdiamond_ inclusions in zircons 4252 Age ranges (in Ma) of diamond deposits, diamond-bearing rocks, and diamond inclusion minerals. Harzburgitic Gurneyetal. (2010) Chemistry and structure CARBON NITROGEN Diamond 1 H T>onr> TaVxlo 1 IIA of the Elements ■II B IVB VB VIB VIIB -VII- IB MB 6 1 7 \ -N 14.01 3 Li 4 Be 11 Na 12 Mg L2.0 19 K 20 Ca 21 SC 22 Ti 23 V 24 Cr 25 Mn 26 Fe 27 Co 28 Ni 29 Cu JO Zn lib 38 Sr 39 Y 40 Zr 41 Nb 42 Mo 4:3 Tc 44 Ru 45 Rh 46 Pd 47 Ag 48 Cd In Sn b Te 1 Xe 55 Cs 56 Ba 57 *La 72 Hf 73 Ta 74 w 75 Re 76 Os 77 lr 78 Pt 79 Au 80 Hg 81 TI 82 Pb 83 Bi 84 Po 85 At 86 Rn 87 Fr 88 Ra 89 ♦Ac 104 Rf 105 Ha 106 sg 107 Ms 103 HS 109 Mt 110 110 in 111 112 11? 113 113 * Lanthanide 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Series Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu + Actinide 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Series Th Pa u Np Pu Am Cm Ilk Cf Es Fm Md No Lr - Simple chemistry <& compact structure, - The hardest mineral - Chemically and mechanically stable: - during long history in the mantle - During transportation in magma - In surface environment Octahedron Cube Carbon in the Earth 10 -1 5 -« TEMPERATURE CO From Tappert and Tappert (2011), Day (2012) V) s_ Q. ■ Carbonate Diam\ ■ s "Graphite / C-0 fluid - -2.5 -2.1 -0.9 1420 o M 1380 3 ■H a s_ 1340 1300 0.5 -1.7 -1.3 Alogf02 (Frost <& Wood, 1997) c + o2 = co2 fluid C02 + (Ca,Mg)0 = (Ca,Mg)C03 carbonate - High Pressure, - low Temperature, - Reduced conditions 0.5 0.0 -0.5 « w-1.0 o «-1.5 -2.0 Luth (2013) -FsMC -2.5 L— 500 DCO EMOD DCDD DCDD 700 900 1100 1300 1500 Temperature (°C) c + o2 = co2 Peridot ite: MgSi03 + MgC03 = Mg2Si04 + C + 02 enstatite magnesite olivine diamond Eclogite: CaMg(C03)2 + 2Si02 = CaMgSi206 + 2C + 202 dolomite coesite diopside diamond Where do we find diamonds? MO- ^ '-I'll-1 • I ' I-< ! 300 TO MO tlOO 1X0 'too TIMPERARIRE CO From Tappert and Tappert (2011), Day (2012) 7 Where do we find diamonds? Diamond primary sources after Hag gerty, 1986 Unconventional diamond sources Headless placer diamond deposits: East-Australian diamonds: Kalimantan diamonds: Davies et al., 2002 Die- Mesozoic Tasimnideorogen middle Paleozoic y Mesozoic Proterozoic and Archean cratons Early to niddle Paleo2oic Diamond-bearing alluvium: Gold, cassiterite, corunmum, topaz, almandin garnet, zircon mature placer, no Diamond Indicator Minerals East Malaya & West Sumatra Block, Devonian (Gondwana) Sibumasu Terrane, Early Permian (Gondwana) Chantaburry Terrane, Carboniferious-Permian (Cathaisialand) Argoland Block, Late Triassic -Late Jurassic (Gondwanaland) South China Terranes Cretaceous Tertiary East Sulawesi Terranes, Cenozoic (Papua New Guinea) Densely dashed line: terrane boundary Thin dashed: inferred terrane boundary 500 km Kuteretal. (2016) Unconventional diamond sources Diamonds in Placers FORMATION UPLIFT SOURCE OF PLACER DIAMONDS MINERAL INDICATORS DIAMOND FEATURES Subduction Zone Cratonic Roots Magmas \ I Ancient Pre-Cambrian Kimberlitepipes or Ancient Paleozoic collectors other diatremes collectors I I I None Kimber lite indicator (minerals of mature minerals (KIM) placer deposits) Tectonic uplift \ UHP rocks J - macro-, good quality - well-rounded - typical abrasion pits - green color (radiation) Various None (minerals of mature placer deposits) - Macro-, good quality - micro-, poor quality - two-layers, or coat - abrasion pits High-pressure eclogitic minerals (Cpx,garnet) - fibrous - cubes - graphitized Ultra-high pressure rocks Diamond types 0 lithospheric superdeep O alluvial + UHPcrustal impact W Alps; Moldanubicm; Norway; Rhodope; Urals; Kokchetav; Qinling; Dabie; Sulu; Kontum; Java; New England Fold Belt; Canadian Cordillera; From Shirey et ol. (2013) $ Ultra-high pressure rocks Discovery of diamond-bearing granulites in Eger Crystalline Complex of North Bohemian Massif | Tertiary volcanic rocks ^ Post-Variscan units | Saxothuringicum undiff. ^ Gneiss-Eclogite Unit _Granulites |^+] Plutonic rocks Kotkovaetal. (2011) P-T evolution of garnet-clinopyroxene UHP rocks from the North Bohemian Massif, Dabie-Sulu, the Kokchetav Massif, and the German Erzgebirge. Sedimentary Carbonates cab ovnonrJ cotte I l.ooof mtnb* 1 irrcrdi II.. ■ul.mli.,.. From Shirey and Shingley (2013) ■» -M *» M -«• H 4 • Mineral inclusions Upper^ mantle Rock type Fluid inclusions (silicic) K+Na Ca+Mg+Fe (saline) (carbonatitic) From Shirey et al. (2013) and references therein 21 Silicate mineral inclusions in diamond used for radioisotopic Rb-Sr and Sm-Nd age dating by Richardson et al. (1984, 1986) Peridotitic Harzburgitic garnet (high in Cr, low in Co) Ecloqitic Orange garnet and colorless clinopyroxene Diamond ages Sulfide mineral inclusions in diamond used for radioisotopic Re- Os age dating by Westerlund et al. (2006), Pearson et al. (1998). Richardson et al., (2001). Peridotitic Ni-rich iron sulfide (pentlandite) Ecloqitic Ni-poor iron sulfide (pyrrhotite) From Shirey and Shingley (2013) 22 Diamond ages Sm-Nd dating of silicate inclusions in diamond Re-Os dating of sulfide inclusions in diamo The data obtained by breaking apart 630 inclusion- Multiple sulfide inclusions bearing diamonds and grouping each set of inclusions as from single diamonds Surface features Morphology of diamonds in six kimberlites from Ekati diamond Mine, Canada. Gurney et al. (2004, 2010). Conditions in the mantle and in kimberlite magma BEARTOOTH PIRANHA loutnugntd 1*9.1 >