The involvement of diamond-forming fluids in the metasomatic ‘cocktail’ of kimberlite sources
The involvement of diamond-forming fluids in the metasomatic ‘cocktail’ of kimberlite sources
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金伯利岩矿源交代“混合物”中钻石形成流体的参与
DOI：
10.1007/s00710-018-0613-8
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发表时间：
2018
影响因子：
1.8
通讯作者：
Goldstein, Steven L.
中科院分区：
文献类型：
--
作者：
Weiss, Yaakov;Goldstein, Steven L.
含微包裹体的金刚石提供了研究克拉通内省地幔交代、金刚石形成和金伯利岩喷发之间关系的机会。我们已经分析了一套7 microinclusions轴承钻石从芬施组II金伯利岩，南非，并确定了两个钻石种群：'芬施IaA'钻石只有氮在A-中心，并含有含盐高密度流体（HDF）microinclusions，而'芬施IaAB'钻石有氮在A-和B-中心（25-35% B-中心），其特征是碳酸盐HDF组合物。基于氮聚集状态和估计地幔居住温度，我们得出结论，“Finsch IaA”金刚石形成于年轻的盐交代事件之前金伯利岩喷发约50万年至15万年。交代作用和碳酸盐岩HDF形成“Finsch IaAB”金刚石的可能时间限制较少，可能发生在喷发前约1500万年至2Gyr之间。两个钻石封装绿辉石微包裹体与盐水或低镁碳酸盐岩样HDF。我们观察到的Al 2 O3 vs的组成差异。这些交代绿辉石之间的CaO，也与地幔榴辉岩中的绿辉石进行了比较，这些榴辉岩被确定为被金伯利岩或高镁碳酸盐岩交代;这表明交代绿辉石中的Al 2 O3和CaO之间可能存在关系，以及与之相互作用的流体/熔体类型。Finsch II组金伯利岩和邻近的I组金伯利岩在Koffiefontein和德比尔斯池的microinclusions轴承金刚石的综合数据表明，大量的西南Kaapvaal深部岩石圈的影响，在白垩纪的盐交代，盐交代，金刚石形成和Kaapvaal晚中生代的“金伯利岩开花”之间的直接关系。因此，我们得出结论，盐HDFs在交代地幔源的积累，导致金伯利岩喷发中发挥了关键作用。
Microinclusion-bearing diamonds offer the opportunity to investigate relationships between mantle metasomatism, diamond formation and kimberlite eruptions in intracratonic provinces. We have analyzed a suite of 7 microinclusion-bearing diamonds from the Finsch Group II kimberlite, South Africa, and identified two diamond populations: ‘Finsch IaA’ diamonds have nitrogen solely in A-centers and contain saline high-density-fluid (HDF) microinclusions, while ‘Finsch IaAB’ diamonds have nitrogen in both A- and B-centers (25–35% B-centers) and are characterized by carbonatite HDF compositions. Based on nitrogen aggregation states and estimates for mantle residence temperatures, we conclude that ‘Finsch IaA’ diamonds formed during a young saline metasomatic event that preceded kimberlite eruption by ~50 kyr to 15 Myr. The possible timing of metasomatism and formation of ‘Finsch IaAB’ diamonds by carbonatite HDFs is less constrained, and could have taken place between ~15 Myr and 2 Gyr before eruption. Two of the diamonds encapsulated omphacite microinclusions in association with saline or low-Mg carbonatitic-like HDF. We observe compositional differences for Al2O3vs. CaO between these metasomatised omphacites, and also compared to omphacites in mantle eclogites which were identified as metasomatised by kimberlite or high-Mg carbonatite; suggesting a possible relationship between Al2O3and CaO in metasomatised omphacite and the type of fluid/melt it interacted with. The combined data for microinclusion-bearing diamonds from the Finsch Group II kimberlite and the neighbouring Group I kimberlites at Koffiefontein and De Beers Pool indicate that a substantial volume of the southwest Kaapvaal deep lithosphere was impacted by saline metasomatism during Cretaceous time, and a direct relationship between saline metasomatism, diamond formation and the Kaapvaal late-Mesozoic ‘kimberlite bloom’. We therefore conclude that saline HDFs play a key role in the buildup of metasomatic mantle sources leading to kimberlite eruptions.
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影响因子：
4.1
作者：
Howell, D.;O'Neill, C. J.;O'Reilly, S. Y.
通讯作者：
O'Reilly, S. Y.
苏必利尔克拉通瓦瓦纤维状钻石中保存的太古代地幔流体
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
Evan M. Smith;M. Kopylova;G. Nowell;D. Pearson;J. Ryder
通讯作者：
J. Ryder
产自南非科菲方丹的浑浊钻石中的流体和矿物包裹体
DOI：
--
发表时间：
2004
期刊：
影响因子：
--
作者：
E. Izraeli;J. Harris;O. Navon
通讯作者：
O. Navon
影响因子：
3.5
作者：
Aulbach, Sonja;Shirey, Steven B.;Harris, Jeff W.
通讯作者：
Harris, Jeff W.
产自南非芬什金伯利岩的两块含钻石橄榄岩捕虏体
DOI：
--
发表时间：
1982
期刊：
影响因子：
--
作者：
S. Shee;J. Gurney;D. Robinson
通讯作者：
D. Robinson