Nanometric inclusions of carbonates in Kokchetav diamonds from Kazakhstan: A new constraint for the depth of metamorphic diamond crystallization

Dobrzhinetskaya, L.; Wirth, Richard; Green, Harry W.

doi:10.1016/j.epsl.2005.11.030

Cited by 66 publications

(40 citation statements)

References 26 publications

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“…Diamond and coesite inclusions identified in the garnet porphyroblasts point to peak metamorphic conditions of P$4-6 GPa and T$950-1000 C (Sobolev & Shatsky, 1990;Hermann et al, 2001;Korsakov et al, 2007). Higher peak metamorphic conditions of P$6-8 GPa and T ¼ 1100 C have been reported by Ota et al (2000), Massonne (2003) and Dobrzhinetskaya et al (2006). Monocrystalline quartz inclusions occur in the core of garnet porphyroblasts similarly to the coesite-grade samples.…”

Section: Sample B01-3mentioning

confidence: 56%

Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman spectroscopy of quartz inclusions in ultrahigh-pressure garnets

Korsakov¹,

Perraki²,

Zhukov³

et al. 2010

ejm

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Laser Raman microspectroscopy was applied to quartz inclusions in coesite-and diamond-grade metapelites from the Kokchetav ultrahigh-pressure metamorphic (UHPM) complex, Northern Kazakhstan, and diamond-grade eclogite xenoliths from the Mir kimberlite pipe, Yakutiya, Russia to assess the quantitative correlation between the Raman frequency shift and metamorphic pressure. Quartz crystals sealed in garnets have a higher frequency shift than those in the matrix. Residual pressures retained by quartz inclusions depend on the metamorphic history of the garnet host. The Raman frequency shift of quartz inclusions in garnet from coesite-grade and diamond-grade metamorphic rocks shows no systematic change with increasing peak metamorphic pressures. The highest shifts of the main Raman bands of quartz were documented for monocrystalline quartz inclusions in garnets from a diamond-grade eclogite xenolith. Calibrations based on experimental work suggest that the measured Raman frequency shifts signify residual pressures of 0.1-0.6 GPa for quartz inclusions from coesite-grade metapelites from Kokchetav, 0.1-0.3 GPa for quartz inclusions from diamond-grade metapelites from Kokchetav, and 1.0-1.2 GPa for quartz inclusions from the diamondgrade eclogite xenoliths from the Mir kimberlite pipe. Normal stresses and internal (residual) pressures of quartz inclusions in garnet were numerically simulated with a 3-shell elastic model. Estimated values of residual pressures are inconsistent with the residual pressures estimated from the frequency shifts. Residual pressure slightly depends on P-T conditions at peak metamorphic stage. Laser Raman microspectroscopic analysis of quartz is a potentially powerful method for recovering an ultrahigh pressure metamorphic event. Monocrystalline quartz inclusions yielding a residual pressure greater than 2.5 GPa might indicate the presence of a former coesite.

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Section: Sample B01-3mentioning

confidence: 56%

Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman spectroscopy of quartz inclusions in ultrahigh-pressure garnets

Korsakov¹,

Perraki²,

Zhukov³

et al. 2010

ejm

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“…In addition, inclusions of aragonite and magnesite in diamonds from the UHP Kokchetav Massif, Northern Kazakhstan, identified by TEM with focused ion beam, indicate even higher pressures of approximately 6-9 GPa (Dobrzhinetskaya et al, 2006), on the basis of earlier experimental studies (Buob et al, 2006;Hermann, 2003a;Irving & Wyllie, 1975;Luth, 2001;Sato & Katsura, 2001).…”

Section: Introductionmentioning

confidence: 99%

“…Aragonite inclusions in diamond have recently been interpreted as evidence of very deep subductions of roughly 280 km (Dobrzhinetskaya et al, 2006) although P-T conditions for the main eclogite stage in the eclogites from the relevant Jaeren nappe in the Norwegian Caledonian orogenic belt, have been estimated at 2.3-2.8 GPa and 585-655 C (Smit et al, 2008). Aragonite and magnesite present clear disequilibrium textures, indicating the replacement of magnesite by aragonite (Smit et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…To date the P max for subducted continental crusts has been estimated at approximately 8-9 GPa (Dobrzhinetskaya et al, 2006;Massonne, 2003;Zhu & Ogasawara, 2002). Most difficulties in the reconstruction of P max conditions for metapelites and metacarbonates are mainly related to the lack of reliable geobarometers in the 2.0-8.0 GPa interval (Hermann, 2002(Hermann, , 2003bHermann & Green, 2001;Lappin & Smith, 1981), although significant progress has been made lately (Thomsen & Schmidt, 2008, and references therein).…”

Section: Introductionmentioning

confidence: 99%

“…Inclusions in robust minerals that point to UHPM comprise diamond (C), coesite (SiO 2 ), TiO 2 polymorph with a-PbO 2 structure. Because of the generally very small size of the UHPM inclusions, which are close to the optical limit, analytical techniques for the accurate investigation of these inclusions are largely confined to transmission electron microscopy (TEM) (Dobrzhinetskaya et al, 2006;Hwang et al, 2001Hwang et al, , 2004Hwang et al, , 2005Langenhorst, 2003) and Raman spectroscopic point analysis and mapping (Korsakov et al, 2007;O'Brien & Ziemann, 2008;Ogasawara et al, 2002;Perraki et al, 2006Perraki et al, , 2007.…”

Section: Introductionmentioning

confidence: 99%

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Aragonite-calcite-dolomite relationships in UHPM polycrystalline carbonate inclusions from the Kokchetav Massif, northern Kazakhstan

Korsakov¹,

Gussem²,

Zhukov³

et al. 2010

ejm

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The presence of aragonite in polycrystalline carbonate inclusions in garnet in diamond-grade metamorphic rocks from the Kokchetav Massif, N. Kazakhstan was identified for the first time by means of Raman analyses and mapping, cathodoluminescence images and optical and scanning electron microscopy. Aragonite appears within the inclusions as dirty, chaotically oriented materials surrounded by a clean monocrystalline calcite shell; the grain boundary between the host-garnet and the aragonite-bearing inclusions is often characterized by a wavy or amoeboid shape; no cracks occur around the aragonite-bearing inclusions; no significant shift in the main aragonite Raman band was measured. These observations indicate that residual pressure within the inclusion is minor. These features are inconsistent with an origin of aragonite at peak metamorphic conditions (6 GPa) by decomposition of dolomite.

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Rheology of magnesite

et al. 2014

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We deformed two natural magnesite aggregates (grain sizes of 1 versus 100 μm) over a wide range of temperatures (400-1000°C) and strain rates (10 À7 -10 À4 /s) in order to determine the deformation mechanisms of magnesite and their respective flow laws. Experiments using fine-grained magnesite were performed in a Heard gas confining medium rock deformation apparatus at a constant effective pressure (= confining pressure À CO 2 pressure) of 300 MPa. Experiments using coarse-grained magnesite were performed in a Griggs piston-cylinder rock deformation apparatus at a constant effective pressure of 900 MPa. At low temperatures (T < 600°C, strain rate = 10 À5 /s) both magnesite aggregates deform by crystal plastic mechanisms predominated by dislocation glide. At higher temperatures the coarse-grained magnesite deforms by dislocation creep and the fine-grained magnesite deforms by diffusion creep. The strain rate and temperature dependence of the strength of magnesite deforming by low-temperature plasticity, dislocation creep, and diffusion creep can be described by power law flow laws with stress exponents (n) of 19.7, 3.0, and 1.1 and activation enthalpies of 229, 410, and 209 kJ/mol, respectively. The strength of the low-temperature plasticity data can also be described using an exponential flow law with α = 0.022 MPa À1 with an activation enthalpy of 233 kJ/mol. Extrapolation of the flow laws to natural conditions indicates that magnesite is generally stronger than calcite and dolomite assuming similar grain sizes. However, its strength is orders of magnitude lower than olivine at all conditions in the Earth's mantle and may promote deep-focus earthquakes through ductile instabilities.

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Nanometric inclusions of carbonates in Kokchetav diamonds from Kazakhstan: A new constraint for the depth of metamorphic diamond crystallization

Cited by 66 publications

References 26 publications

Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman spectroscopy of quartz inclusions in ultrahigh-pressure garnets

Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman spectroscopy of quartz inclusions in ultrahigh-pressure garnets

Aragonite-calcite-dolomite relationships in UHPM polycrystalline carbonate inclusions from the Kokchetav Massif, northern Kazakhstan

Rheology of magnesite

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