Kaapvaal lamproite melts (aka orangeites): A new type of alkali-carbonate liquid? insights from olivine-hosted multiphase inclusions (Silvery Home, South Africa)
文献类型：期刊论文
| 作者 | Abersteiner, Adam4,5,6; Tarasov, Alexey3; Golovin, Alexander3; Howarth, Geoffrey H.2; Kamenetsky, Vadim S.1 |
| 刊名 | GEOSCIENCE FRONTIERS
 |
| 出版日期 | 2024-09-01 |
| 卷号 | 15期号:5页码:15 |
| 关键词 | Lamproite Kaapvaal Multiphase inclusions Olivine Orangeite |
| ISSN号 | 1674-9871 |
| DOI | 10.1016/j.gsf.2024.101864 |
| 通讯作者 | Abersteiner, Adam(adam.abersteiner@adelaide.edu.au) |
| 英文摘要 | Kaapvaal lamproites (aka orangeites) are a group of volatile-rich (H2O, CO2), micaceous, ultrapotassic igneous rocks that are unique to the Kaapvaal craton in southern Africa. However, the composition of the melts that give rise to these rocks remains poorly understood due to overprinting effects of contamination by mantle and crustal material, volatile exsolution, fractional crystallisation and post-magmatic alteration. Consequently, this lack of reliable data on the initial composition of the Kaapvaal lamproite melts hampers our understanding of their source, petrogenesis and ascent mechanisms. Olivine is a common mineral comprising the Kaapvaal lamproites that has both xenocrystic (i.e., mantle) and magmatic origins. Multiphase inclusions (melt/fluid) entrapped within olivine have been consistently demonstrated as an effective tool for gaining fundamental insights into the composition and evolution of melts that produce both kimberlites and lamproites, prior to processes, such as eruption, devolatization and syn-/post-magmatic alteration. In this study, multiphase inclusions of both secondary and pseudosecondary origin hosted in olivine from a Kaapvaal lamproite (Silvery Home, South Africa) provide novel insights into the composition of the melt(s) that initially transported olivine to the surface and then crystallised after emplacement to form the lamproite groundmass. The inclusions in our study contain daughter mineral assemblages consisting of diverse Ca-Mg carbonates, including K-, Na-, Ba-, and Sr-bearing varieties, moderate K-rich silicates (phlogopite, tetraferriphlogopite), and subordinate oxides, phosphates, sulphides, sulphates, and halides. Based on these daughter mineral assemblages, we suggest that the composition of the melt entrapped by olivine was SiO2-poor, Ca-Mg carbonate-rich and contained elevated concentrations of K, Na, Ba, Sr, P and Cl. The mineral and reconstructed melt compositions are in stark contrast to the mineral association of the groundmass and the bulk-rock composition of the Silvery Home lamproite, respectively. We suggest that alkali-/alkali-earth carbonates, phosphates, sulphides, sulphates, and halides represented a potentially significant, or even dominant, component of the melt that crystallised the Silvery Home lamproite but were likely removed by degassing and/or interaction with syn-/post-magmatic fluids. We show that olivine-hosted multiphase inclusions from the Silvery Home lamproite share many compositional similarities to melt inclusions hosted in olivine from kimberlites but are distinct from 'classic' cratonic olivine lamproites worldwide. (c) 2024 China University of Geosciences (Beijing) and Peking University. Published by Elsevier B.V. on behalf of China University of Geosciences (Beijing). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
| WOS关键词 | TRACE-ELEMENT ANALYSIS ; GROUP-II KIMBERLITES ; X-RAY-DIFFRACTION ; RAMAN-SPECTROSCOPY ; PETROGENESIS ; DIAMONDS ; FLUID ; METASOMATISM ; GEOCHEMISTRY ; EVOLUTION |
| 资助项目 | K. H. Renlund Foundation (Finland)[0016] ; Future Making Fellowship (University of Adelaide) ; IGM SB RAS[122041400157-9] |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:001345508100001 |
| 出版者 | CHINA UNIV GEOSCIENCES, BEIJING |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/199348]  |
| 专题 | 海洋研究所_深海极端环境与生命过程研究中心 |
| 通讯作者 | Abersteiner, Adam |
| 作者单位 | 1.Chinese Acad Sci, Inst Oceanol, Ctr Deep Sea Res, Qingdao 266071, Peoples R China 2.Univ Cape Town, Dept Geol Sci, ZA-7701 Rondebosch, South Africa 3.Russian Acad Sci, VS Sobolev Inst Geol & Mineral, Siberian Branch, Novosibirsk, Russia 4.Univ Adelaide, Sch Phys Sci, Dept Earth Sci, Adelaide, SA 5005, Australia 5.Univ Adelaide, Inst Sustainabil Energy & Resources, Adelaide, SA 5005, Australia 6.Univ Helsinki, Dept Geosci & Geog, Res Programme Geol & Geophys GeoHel, Helsinki, Finland |
| 推荐引用方式 GB/T 7714 | Abersteiner, Adam,Tarasov, Alexey,Golovin, Alexander,et al. Kaapvaal lamproite melts (aka orangeites): A new type of alkali-carbonate liquid? insights from olivine-hosted multiphase inclusions (Silvery Home, South Africa)[J]. GEOSCIENCE FRONTIERS,2024,15(5):15. |
| APA | Abersteiner, Adam,Tarasov, Alexey,Golovin, Alexander,Howarth, Geoffrey H.,&Kamenetsky, Vadim S..(2024).Kaapvaal lamproite melts (aka orangeites): A new type of alkali-carbonate liquid? insights from olivine-hosted multiphase inclusions (Silvery Home, South Africa).GEOSCIENCE FRONTIERS,15(5),15. |
| MLA | Abersteiner, Adam,et al."Kaapvaal lamproite melts (aka orangeites): A new type of alkali-carbonate liquid? insights from olivine-hosted multiphase inclusions (Silvery Home, South Africa)".GEOSCIENCE FRONTIERS 15.5(2024):15. |
入库方式： OAI收割
来源：海洋研究所
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