Diamond and Other Possible Ultradeep Evidence Discovered in the Orogenic Spinel-Garnet Peridotite from the Moldanubian Zone of the Bohemian Massif, Czech Republic

Forbidden mineral assemblage coesite‐disordered graphite in diamond‐bearing kyanite gneisses (Kokchetav Massif)

“…The coexistence of graphite crystals with different degrees of crystallinity shows that several different graphite‐forming processes are recorded in UHPM diamondiferous rocks. The appearance of disordered graphite in UHPM rocks in general is attributed to partial diamond graphitization . However, diamonds were identified neither in intergrowths with coesite, nor in coesite inclusions from kyanite porphyroblasts.…”

“…Raman spectroscopy of graphites from UHPM samples revealed G‐ and D‐bands; the latter are attributed to structure defects . The diamond graphitization during the retrograde stage of metamorphism is the most popular model for explaining the presence of disordered graphite in UHP‐HT complexes . However, there are three alternative models for disordered graphite formation which can be summarized as follows.…”

Graphite pseudomorphs after diamonds: An experimental study of graphite morphology and the role of H2O in the graphitisation process

“…Raman spectra were recorded from 100 to 4000 cm -1 . Similarly to Naemura et al (2011), band position, band height, band area and band width (i.e., full width at half maximum, FWHM) were determined after baseline correction and curve fitting with the Voigt function by applying data analysis software Fityk 0.8.9.…”

“…In contrast to kimberlites, where black and/or graphite-coated diamonds rarely occur (Grenville-Wells, 1952), diamonds in the UHPM rocks often coexist with graphites (Dobrzhinetskaya et al, 2009;Janak et al, 2013;Katayama et al, 2000;Korsakov & Shatsky, 2004;Korsakov et al, 2010;Massonne et al, 1998;Naemura et al, 2011;Ogasawara et al, 2000;Perraki et al, 2006Perraki et al, , 2009Zhang et al, 1997;Zhu & Ogasawara, 2002). Metastable growth of graphite in the diamond stability field was documented for ultra-high-pressure metamorphic rocks from the Kokchetav massif (Korsakov & Shatsky, 2004;Korsakov et al, 2010).…”

Accessory priderite and burbankite in multiphase solid inclusions in the orogenic garnet peridotite from the Bohemian Massif, Czech Republic

“…In the Plešovice quarry, a garnetiferous perpotassic granulite, consisting of pyrope-rich garnet, ternary feldspar, and quartz, occurs as lense/layers in the Gföhl granulite. The pressure-temperature path of the peridotite was identified by Naemura et al (2009Naemura et al ( , 2011, who proposed that the phlogopite-bearing spinel-garnet peridotite experienced a multiple exhumation history, including the intial garnet peridotite assemblage in the diamond-stability field (Stage 1, P >4 GPa), exhumation to the chlorite peridotite field (Stage 2, T~700°C, P~2 GPa), subducted to the garnet lherzolite field (Stage 3) at 2.9 GPa at 950°C, followed by exhumation to the spinel lherzolite field (Stage 4) at~750°C. Naemura et al (2009) envisaged that such a multiple exhumation path could be realized in the corner flow motion in the mantle wedge, with the mantle-wedge peridotite being entrained into the subducted continental crust (Gföhl granulite) by the sinking intrusion mechanism (Brueckner, 1998).…”