Garnet from Cr- and Ca-saturated mantle: implications for diamond exploration

Kopylova, Maya G.; Russell, James K.; Stanley, Clifford R.; Cookenboo, H.

doi:10.1016/s0375-6742(00)00004-2

Cited by 39 publications

(26 citation statements)

References 27 publications

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“…Abbreviations are as in Table 1. rock (harzburgite, lherzolite or wehrlite) from which the former are derived. But, getting information on pressure and hence depth from the major element composition of concentrate garnets is complicated by the fact that their compositions are controlled by several factors including P, T, parental bulk composition and mineral assemblage (Kopylova et al, 2000;Klemme, 2004). Pressures calculated from mantle xenoliths provide direct constraint on the depth from which they are derived.…”

Section: Lithospheric Mantle Stratigraphymentioning

confidence: 99%

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Major element composition of concentrate garnets in Proterozoic kimberlites from the Eastern Dharwar Craton, India: Implications on sub-continental lithospheric mantle

Patel¹,

Ravi²,

Anilkumar³

et al. 2010

Journal of Asian Earth Sciences

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Section: Lithospheric Mantle Stratigraphymentioning

confidence: 99%

“…Fields of harzburgitic, lherzolitic and wehrlitic garnets afterGrütter et al (2004). CGGE is the chromiteclinopyroxene-garnet equilibrium trend afterKopylova et al (2000). (b and d) Ca components vs. Cr components in garnets afterSobolev et al (1973).…”

mentioning

confidence: 99%

Major element composition of concentrate garnets in Proterozoic kimberlites from the Eastern Dharwar Craton, India: Implications on sub-continental lithospheric mantle

Patel¹,

Ravi²,

Anilkumar³

et al. 2010

Journal of Asian Earth Sciences

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“…Layer A is distinguished by enigmatic CCGE garnets (named after clinopyroxene-chromite-garnetequilibrium by Kopylova et al, 2000) that are depleted with respect to Ti, Y, Zr and REE but fertile in their major element compositions, as demonstrated by elevated Ca contents. Layer A peridotites have "ultradepleted" arc mantle -type compositions, and have been metasomatised by radiogenic 187 Os/ 188 Os, presumably as a result of metasomatism by slab-derived fluids (Peltonen & Brügmann, 2006).…”

Section: Summary Of Results From Kaavi-kuopiomentioning

confidence: 99%

“…Arrow pointing NE in the Kaavi-Kuopio diagram marks the "CCGE" garnet trend, i.e. chromite-clinopyroxene-garnet equilibrium, recognized in spinel-garnet peridotites from the Jericho kimberlite by Kopylova et al (2000). Layer A explained in text, section 1.1.…”

Section: Clinopyroxene Thermobarometrymentioning

confidence: 98%

Mantle transect of the Karelian Craton from margin to core based on P-T data from garnet and clinopyroxene xenocrysts in kimberlites

Lehtonen¹,

O’Brien²

2009

Bull Geol Soc Finland

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Peridotitic garnet and clinopyroxene xenocrysts from the 1.2 Ga Lentiira-Kuhmo and the 760 Ma Kuusamo kimberlite fields, emplaced within the Central Karelian Craton, have been studied using major and trace element geochemistry to obtain information on the stratigraphy, compositional variability, and evolutionary history of the underlying lithospheric mantle. An earlier study on the 600 Ma Kaavi-Kuopio kimberlite field showed that near the SW margin of the craton the 230-km-thick subcontinental lithospheric mantle (SCLM) exhibits a well-developed 3-layer structure indicative of episodic construction.

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“…Hood and McCandless (2004) suggested that these peripheral bodies might be sourced by a chromite-clinopyroxene-garnet equilibrium (CCGE) trend (Kopylova et al 2000) and wehrliticwebsteritic lithosphere, respectively. This implies that both emplacement ages and mantle-lithosphere sources (i.e., spatial location) are important considerations for diamond content in the BHH kimberlite field.…”

Section: Characteristics Of *88-81 Ma Volcanismmentioning

confidence: 99%

Rb–Sr and U–Pb geochronology and setting of the Buffalo Head Hills kimberlite field, northern AlbertaThis article is one of a selection of papers published in this Special Issue on the themeGeology of northeastern British Columbia and northwestern Alberta: diamonds, shallow gas, gravel, and glaciers.

et al. 2008

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New Rb-Sr phlogopite and U-Pb perovskite age determinations for 12 of 38 known ultramafic bodies in the Buffalo Head Hills area of north-central Alberta show that kimberlitic magmatism occurred in at least two separate episodes during Late Cretaceous and Paleocene time. Nine kimberlites yield Coniacian to Campanian ages of between 88 ± 5 Ma (U-Pb perovskite, K5A) and 81.2 ± 2.3 Ma (Rb-Sr phlogopite, K252). A Danian U-Pb perovskite isochron age of 63.5 ± 0.7 Ma was obtained for the BM2 kimberlite, and Selandian Rb-Sr ages of 59.6 ± 2.8 and 60.3 ± 0.8 Ma were determined for the K1A and K19 bodies, respectively. These specific periods of magmatism correspond to characteristic intra-field features such as kimberlite spatial distribution, diamond content, rock classification, and mechanisms of emplacement. The *88-81 Ma group generally occurs in the northwestern part of the field and defines the diamond window for the Buffalo Head Hills kimberlite field. This volcanism is contemporaneous with sedimentary host rock deposition, which has important implications for the size and morphological complexity of the kimberlite bodies. The *64 Ma BM2 body represents the only known occurrence of hypabyssal-facies kimberlite in this field and is similar in terms of source composition to the *88-81 Ma kimberlites, but is not diamond bearing. The *60 Ma group occurs in the southwestern part of the field, is derived from a weakly diamondiferous -barren hybrid ultramafic source and features bodies that are eroded to present-day stratigraphic levels. Résumé :De nouvelles déterminations d'âges Rb-Sr sur phlogopite et U-Pb sur pérovskite pour 12 des 38 amas ultramafiques connus dans le secteur de Buffalo Head Hills, dans le centre-nord de l'Alberta, montrent que le magmatisme kimberlitique s'est produit au moins au cours de deux épisodes distincts aux époques du Crétacé tardif et du Paléocène. Neuf kimberlites ont donné des âges Coniacien à Campanien entre 88 ± 5 Ma (U-Pb sur pérovskite, K5A) et 81,2 ± 2,3 Ma (Rb-Sr sur phlogopite, K252). Un âge isochrone Danien U-Pb sur pérovskite de 63,5 ± 0,7 Ma a été obtenu pour la kimberlite BM2 et des âges Sélandien Rb-Sr de 59,6 ± 2,8 et de 60,3 ± 0,8 Ma ont été déterminés respectivement pour les amas K1A et K19. Ces périodes spécifiques de magmatisme correspondent à des structures caractéristiques intra-champs, telles que la distribution spatiale de la kimberlite, le contenu en diamants, la classification de la roche et les mécanismes de mise en place. Le groupe dont l'âge est d'environ 88 à 81 Ma, se retrouve généralement dans la partie nord-ouest du champ et il définit la fenêtre diamantifère du champ de kimberlites Buffalo Head Hills. Ce volcanisme est contemporain de la dép-osition des roches encaissantes sédimentaires, ce qui a des implications significatives pour la dimension et la complexité morphologique des amas de kimberlite. L'amas BM2, *64 Ma, représente la seule occurrence connue de kimberlite à faciès hypabyssal dans ce champ et sa composition source est similaire aux kimberlites *8...

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Garnet from Cr- and Ca-saturated mantle: implications for diamond exploration

Cited by 39 publications

References 27 publications

Major element composition of concentrate garnets in Proterozoic kimberlites from the Eastern Dharwar Craton, India: Implications on sub-continental lithospheric mantle

Major element composition of concentrate garnets in Proterozoic kimberlites from the Eastern Dharwar Craton, India: Implications on sub-continental lithospheric mantle

Mantle transect of the Karelian Craton from margin to core based on P-T data from garnet and clinopyroxene xenocrysts in kimberlites

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