... mantle environment and incorporated into large-scale mantle dynamics is also gained from these studies. Figure 1. World map of coesite and non-cratonic microdiamond occurrences within Precambrian, Pan–African, Paleozoic and Mezozoic orogens. Numbers indicate age of UHP metamorphism in Ma. Sx...

... in the biotite gneisses of the Kumdy-Kol microdiamond deposit. The diamondiferous garnet–pyroxene rocks consist mainly of garnet and clinopyroxene with small amounts of carbonate and K-feldspar. The pyroxene in diamondiferous garnet–pyroxene rocks is characterized by the presence of potassium...

... for the distinction of microdiamonds in ultrahigh-pressure metamorphic rocks from diamonds in sample preparation materials . American Mineralogist , 94 , 546 – 556 . Rubatto D. and Hermann J. ( 2007 ) Zircon behaviour in deeply subducted rocks . Elements , 3 , 31 – 35 . Rubatto D...

...‰. The diamond grains are 0.06–0.7 mm in size (i.e., they may be called microdiamonds) and are colorless to yellow-green in color ( Fig. 4 ). They are accompanied, in samples, with single grains of moissanite, milky-white corundum, various spinellides, sulfides, Cu-Sn alloys, and native iron, aluminum...

...Katarzyna Walczak; Simon Cuthbert; Ellen Kooijman; Jarosław Majka; Matthijs A. Smit Abstract The first find of microdiamond in the Nordøyane ultra-high-pressure (UHP) domain of the Western Gneiss Region (WGR) of the Scandinavian Caledonides reshaped tectonic models for the region. Nevertheless...

..., Northwest Territories . Int. Geol. Rev. 37 , 212 – 229 . Moe , K. , Yang , J. , Johnson , P. , Xu , X. , Wang , W. , 2017 . Spectroscopic analysis of microdiamonds in ophiolitic chromitite and peridotite . Lithosphere 10 ( 1 ), 133...

... and microdiamond have been found. In ZSZ serpentinites, the new UHP assemblage predates the previously recognized HP-UHP paragenesis, which was recently dated at 65 Ma. This finding opens up a new interpretation for the petrologically and structurally well-constrained HP/UHP records, especially because all other...

...Xiangzhen Xu; Pierre Cartigny; Jingsui Yang; Yildirim Dilek; Fahui Xiong; Guolin Guo Abstract We report new δ 13 C data and N content and aggregation state values for microdiamonds recovered from peridotites and chromitites of the Luobusa ophiolite (Tibet) and chromitites of the Ray-Iz ophiolite...

...Kyaw Soe Moe; Jing-Sui Yang; Paul Johnson; Xiangzhen Xu; Wuyi Wang Abstract Microdiamonds ∼200 µm in size, occurring in ophiolitic chromitites and peridotites, have been reported in recent years. Owing to their unusual geological formation, there are several debates about their origin. We studied...

... 300 nA beam current and 200 ms dwell times. To avoid confusion, the abbreviation “P” is used only for phosphorous; pressure is written out in full except for the abbreviations “HP” and “UHP”. One example is from UHP microdiamond-bearing quartzofeldspathic lenses of “saidenbachite” in the gneiss...

... in ultrahigh-pressure quartzofeldspathic gneisses of the Kumdy-Kol area of the Kokchetav Massif, northern Kazakhstan. Maruyamaite contains inclusions of microdiamonds, and probably crystallized near the peak pressure conditions of UHP metamorphism in the stability field of diamond. Crystals occur as anhedral...

... , M.A. , 1991 . New occurrence of microdiamonds in metamorphic rocks as proof for regional ultrahigh-pressure metamorphism in the Kokchetav massif . Dokl. Akad. Nauk SSSR 321 ( 1 ), 189 – 193 . Shatsky , V.S. , Jagoutz , E. , Kozmenko , O.A...

..., electron probe microanalysis, and transmission/analytical electron microscopy. The obtained results confirmed the presence of microdiamonds and indicative signs of ultrahigh pressures (K in clinopyroxene) for seven of the eight previously recognized layers of the sample. Only one layer (3) containing...

..., 1995 ; Dobretsov, 2003 , 2010 , 2011 ; Dobretsov and Buslov, 2004 , 2007 , 2011 ; Dobretsov et al., 1995a , b , c ; Ernst and Liou, 2008 ; Ernst et al., 1995 , 2007 ; Korobkin and Smirnov, 2006 ). The presence of microdiamond inclusions in garnet, pyroxene, and zircon from garnet–pyroxene...

... are known from several occurrences worldwide. We report on the discovery of microdiamond in kyanite-garnet gneiss from allochthonous metasediments of the Seve Nappe Complex in the Scandinavian Caledonides. Our discovery calls for general reconsideration of existing exhumation models of deeply subducted...

... that kumdykolite contains 2 wt% CaO, probably indicating significant miscibility with the Ca-end-member svyatoslavite. Similar to the case of microdiamond inclusions, the kumdykolite-bearing multiphase inclusion is located in the Ca- and Mg-rich central part of the garnet and thus must have been trapped at P...