Origin of Kimberlite Magma

金伯利岩岩浆的起源

基本信息

批准号：
62470049
负责人：
ARIMA Makoto
金额：
$ 3.84万
依托单位：
Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

The aims of this project are to determine the phase equilibrium of a kimberlite composition, which is thought to be close to a primary kimberlite magma composition, and to examine chemical and stable isotopic characteristics of several kimberlites occurring in North American. The results of this study are summarized as following.1. High pressure experiments (10-40 kb,100-1500 C) on an aphanitic kimberlite composition from the Wesselton Mine, South Africa, indicate that this kimberlite composition could be equilibrated with a mineral assemblage of olivine, clinopyroxene, spinel, calcite, and perovskite at upper mantle conditions. Monticellite occurs at relatively lower pressures while clinopyroxene stability is limited at higher pressures. The untipathy of monticellite and clinopyoxene in the experiments may be used to explain the incompatibility of these phases in kimberlites. Kimberlite magmas could be partial melts derived calcite-bearing upper mantle material of deverse mineralogy. … More 2. Micaceous ultramafic dikes of Jurassic age from Picton and Varty Lake, Ontario, Canada, consist mineralogically of olivine-phlogopite-calcite-serpentine-spinel. The dikes exhibit pronounced enrichments of light rare earth elements combined relatively high CO2. Calcite in the dikes is a primary magmatic phases, from textural relations and C-isotopic compositions. The dikes are hypabyssal facies kimberlite. 3. Barium-rich phlogopite occurs in a mantle derived xenolith incorporated into the Upper Canada Mine Kimberlite, Ontario. The phlogopite is characterized by high BaO (up to 4.3 wt.%) with a high Mg, Na, and low Ti. The chemical characteristics of the phlogopite suggest that the mica has been formed by mantle metasomatism involving Ba- and alkali-rich, Ti-poor hydrous fluids. A range of Ba/K in mantle derived phlogopites is comparable with that in the continental alkali volcanic rocks and in the mantle derived xenoliths, suggesting that phlogopite may be a principal reservoir for Ba in the upper mantle. Less

该项目的目的是确定金伯利岩组成的相等相等的相位，该相位被认为接近原发性金伯利岩岩浆成分，并检查北美几种金伯利石的化学和稳定同位素特性。这项研究的结果总结如下1。高压实验（10-40 kb，100-1500 c）在南非韦塞尔顿矿山（Wesselton Mine）的阿语质金伯利岩组成上表明，这种金伯利岩组成可能等效于橄榄石，clionpopyroine，Clinopyroy，clinopyroxene，clinopyroxene，clinopyroxene，spinel，calcium，calcium，calcium，calcium and Calcium and Califskite和perovskite的矿物质。在较低的压力下，蒙蒂西特岩发生在相对较低的压力下，在较高压力下的稳定性受到限制。在实验中，蒙蒂西特岩和斜氧化的不感觉可用于解释金伯利岩在金伯利岩中这些阶段的不相容性。金伯利岩岩浆可能是衍生钙的含钙的上地幔材料的部分熔体。 …更多2。来自Picton和Varty Lake，加拿大安大略省的Varty Lake的侏罗纪时代的云母超镁铁质堤防，始终如一地矿物质学，始终如一地矿物质学。堤防暴露了明显的稀土元素的富集，相对较高的二氧化碳。堤防中的方解石是质地关系和C-同位素组成的主要岩浆阶段。堤防是金伯利特的hypabyssal脸。 3。富含钡的辉辉岩发生在安大略省上加拿大金贝利特矿山矿山的地幔中。富洛吉岩的特征是高毫克，Na和低Ti的高BAO（高达4.3 wt。％）。磷酸石的化学特征表明，云母是由涉及BA-和富含碱的Ti-Poor含水液形成的。地幔衍生的富洛格岩中的一系列BA/K与大陆碱火山岩和地幔衍生的异种石的范围相当，这表明富洛格属可能是上层厚底的BA的主要储层。较少的