Origin of clinopyroxene megacrysts in volcanic rocks from the North China Craton: a comparison study with megacrysts worldwide
Origin of clinopyroxene megacrysts in volcanic rocks from the North China Craton: a comparison study with megacrysts worldwide
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华北克拉通火山岩中单斜辉石巨晶的成因：与世界巨晶的对比研究
DOI：
10.1080/00206814.2019.1663766
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发表时间：
2019-09
影响因子：
2.6
通讯作者：
Ying Ji-Feng
中科院分区：
文献类型：
--
作者：
Liu Ya-Dong;Ying Ji-Feng
火山岩中的单斜辉石巨晶可以提供有关深部岩浆系统演化的大量信息。虽然这些晶体受到了相当大的关注，但它们的起源尚未完全解决。世界范围内的单斜辉石巨晶一般可分为两大类：绿色铬透辉石型和黑色铝辉石型。有一个共识，认为铬透辉石巨晶是地幔捕虏晶，而两个对立的意见存在关于黑色铝辉石巨晶的起源。一种倾向于同源起源，将它们视为高压下宿主岩浆的结晶产物;而另一种则认为它们是从以前的碱性玄武岩或地幔橄榄岩、辉石岩或伟晶岩脉的碎片结晶出来的捕虏晶。通过对华北地区中新生代火山岩中单斜辉石巨晶的研究，并与世界各地的单斜辉石巨晶进行对比，提出了新的成因限制，即以往认为的Cr-透辉石巨晶都是捕虏晶，代表了富单斜辉石地幔岩中分解的单斜辉石晶体。与以前提出的同源起源相反，铝辉石巨晶也是捕虏晶，与其寄主岩石没有直接的遗传联系。它们是从早于主岩浆形成的熔体中结晶出来的，可能是在岩浆房中积累起来的，或者是以岩片或矿脉的形式出现在上地幔岩浆房周围的裂缝网络中。在随后的宿主熔岩喷发过程中，这些先前形成的晶体被合并到岩浆中并被带到地表。
Clinopyroxene megacrysts in volcanic rocks can provide substantial information on the evolution of the magmatic system at depth. Although considerable attention has been paid to these crystals, their origin is not yet completely resolved. The clinopyroxene megacrysts worldwide can be divided into two major types in general: the green Cr-diopside type and the black Al-augite type. There is a consensus view that the Cr-diopside megacrysts are mantle xenocrysts, whereas two contrasting opinions exist regarding the origin of the black Al-augite megacrysts. One favours a cognate origin, viewing them as crystallization products of the host magmas under high-pressure; while the other argues that they are xenocrysts crystallized from previous alkali basalts or fragments of mantle peridotites, pyroxenites or pegmatite veins. A review study on the clinopyroxene megacrysts in Meso-Cenozoic volcanic rocks from the North China Craton (NCC) and their comparison with those worldwide provides new constraints on their origin, namely, the Cr-diopside megacrysts, as previously thought, are all xenocrysts, representing disaggregated clinopyroxene crystals from clinopyroxene-rich mantle rocks. Contrary to the formerly proposed cognate origin, the Al-augite megacrysts are also xenocrysts, having no direct genetic link to their host rocks. They crystallized from melts that have formed earlier than the host magmas, and probably accumulated in a magma chamber or occurred as sheets or veins filling a fracture network surrounding a magma chamber in the upper mantle. During the subsequent eruption of the host lavas, these previously formed crystals were incorporated into the magma and were brought up to the surface.
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影响因子：
3.5
作者：
A. Moore;G. Costin
通讯作者：
A. Moore;G. Costin
DOI：
10.1007/bf01829378
发表时间：
1991-06
期刊：
Geologische Rundschau
影响因子：
--
作者：
B. Marsh;B. Gunnarsson;R. Congdon;R. Carmody
通讯作者：
B. Marsh;B. Gunnarsson;R. Congdon;R. Carmody
DOI：
--
发表时间：
1969-11
期刊：
--
影响因子：
--
作者：
石橋 澄;K. Ishibashi;キヨシ イシバシ
通讯作者：
石橋 澄;K. Ishibashi;キヨシ イシバシ
影响因子：
3.1
作者：
Kevin S. Richter;I. Carmichael
通讯作者：
Kevin S. Richter;I. Carmichael
中国东部地幔捕虏体及矿物的钙同位素组成
影响因子：
5
作者：
Jin-Ting Kang;Hong-Li Zhu;Yu-Fei Liu;Fang Liu;Fei Wu;Yan-Tao Hao;Xia-Chen Zhi;Zhao-Feng Zhang;Fang Huang
通讯作者：
Fang Huang