The Sytykanskaya kimberlite pipe:Evidence from deep-seated xenoliths and xenocrysts for the evolutio

来源 :Geoscience Frontiers | 被引量 : 0次 | 上传用户:vanechin
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Mantle xenoliths(>150) and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field(Yakutia) were analyzed by EPMA and LAM ICP methods.In P-TX-f(O_2) diagrams minerals from xenoliths show widest variations,the trends P-Fe~#-CaO,f(O_2)for minerals from porphyric kimberlites are more stepped than for xenocrysts from breccia.Ilmenite PTX points mark moving for protokimberlites from the lithosphere base(7.5 GPa) to pyroxenite lens(5-3.5 GPa) accompanied by Cr increase by AFC and creation of two trends P-Fe#OI ~ 10-12%and13-15%.The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 GPa and 600 C near Moho was determined.The oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere base.Highly inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated protokimberlite.Melts for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider diagrams.Garnets reveal S-shaped REE patterns.The clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC differentiation.Melts for garnets display less inclined patterns and Ba-Sr troughs but enrichment in Nb-Ta-U.The~(40)Ar/~(39)Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic(1154 Ma) age of metasomatism in early Rodinia mantle.Veined glimmerites with richterite- like amphiboles mark ~1015 Ma plume event in Rodinia mantle.The ~600-550 Ma stage manifests final Rodinia break-up.The last 385 Ma metasomatism is protokimberlite-related. Mantle xenoliths (> 150) and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field (Yakutia) were analyzed by EPMA and LAM ICP methods. P-TX-f (O_2) diagrams minerals from xenoliths show widest variations, the trends P-Fe ~ # -CaO, f (O_2) for minerals from porphyric kimberlites are more than for xenocrysts from breccia.Ilmenite PTX points mark moving for protokimberlites from the lithosphere base (7.5 GPa) to pyroxenite lens (5 -3.5 GPa) by Cr increase by AFC and creation of two trends P-Fe # OI ~ 10-12% and 13-15%. The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW / m2 at 65 GPa and 600 C near Moho was determined. The oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for for uncontaminated varieties at the lithosphere base. Highly inclined linear REE patterns with deep HFSE troughs for the parental melts of clino pyroxene and garnet xenocrysts from breccia were influenced by differentiated protokimberlite. Melts for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider diagrams. Garnets reveal S-shaped REE patterns. clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC differentiation. Melts for garnets display less inclined patterns and Ba-Sr troughs but enrichment in Nb-Ta-U.The ~ (40) Ar / ~ (39) Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic (1154 Ma) age of metasomatism in early Rodinia mantle. Veined glimmerites with richterite-like amphiboles mark ~ 1015 Ma plume event in Rodinia mantle. ~ 600-550 Ma stage manifests final Rodinia break-up. last 385 Ma metasomatism is protokimberlite-related.
其他文献
教育要与时俱进,深入改革,探索出一条适应中国特色社会主义的教育之路,其核心之一是减轻中小学生的课业负担,改变教学效果的评价方式,把学生的自主时间还给学生。如何使教学
期刊
生活中,新奇的念头常常闪现在我们的头脑中,但绝大多数人只是把它当成一个念头而已,想想就过去了,却不知这些念头中潜藏着巨大的商机。 In life, the idea of ​​novelty o
期刊
摘要:随着社会经济的发展,我国的建筑行业正在向现代化建筑发展,结合了现代化的设计技术和施工技术,提升了建筑设计施工水平,为我国的国民经济发展提供了良好的条件。本文主要对谈建筑设计与施工相关问题进行了简要分析。  关键词:建筑工程;设计;施工  中图分类号:TU198文献标识码: A  一、房屋建筑设计的发展措施  1、房屋建筑舒适性的提高  房屋建筑设计的首要目的在于满足居民的生活需要,以人为本,
鸡西矿业集团公司张辰煤矿西三采区3
期刊
据《俄罗斯国家安全利益》在线杂志近日报道,俄罗斯联邦安全局研究员赫洛布斯托夫日前撰文称,1980年莫斯科奥运会是在充满“恐怖阴影”下进行的,克格勃为保障莫斯科奥运会的
鸡西矿业集团公司张辰煤矿西三采区3
期刊
摘要:轨道交通项目作为一种复杂的大型系统,建设周期长,特别是投资规模大。为了城市的健康发展,必须要控制好工程造价,提高投资的社会效益和经济效益。本文针对我国轨道交通发展的现状和问题、轨道交通工程造价控制的原则每个阶段造价控制措施进行了探讨,仅供参考。  关键词:城市轨道;交通项目;建设;造价;控制  中图分类号:U213文献标识码: A  引言  近年来,我国城市化进程不断加快,造成了城市交通普遍
【教学目标】  1.让学生在探索研究的过程中进一步掌握除数是一位数的除法的计算方法,会计算三位数除以一位数的笔算除法。  2.使学生养成认真计算的好习惯,培养学生爱数学
1937年7月7日,“卢沟桥事件”爆发,拉开了中华民族全面抗战的序幕。国难当头,国共两党合作,共御外侮。此后不久,朱德受命担任国民革命军第八路军总指挥,率部自陕北开赴山西前
用质量损失法研究了65Mn和316L及其Ni-P镀层的冲刷腐蚀行为。结果表明:在试样表面与流体间相对运动距离相同的条件下,65Mn和316L在单相流和两相流中的冲刷腐蚀速率随着介质温