Replacive symplectites (vermicular intergrowths of two or more minerals) are an important feature of layered igneous intrusions, recording evidence of late-stage reactions between interstitial liquid and crystals. They are common throughout the Layered Series of the 564 Ma Sept Iles layered intrusion in Quebec, Canada, and fall into three types: oxy-symplectites, ‘Type I’ symplectites, and ‘Type II’ symplectites. Oxy-symplectites are comprised of magnetite and orthopyroxene, nucleate on olivine primocrysts, and form via the reaction Olivine + O2  Orthopyroxene + Magnetite; Type I symplectites (of which there are 3 distinct categories) are comprised of anorthitic plagioclase with pyroxene, amphibole, or olivine vermicules, grow from primocryst oxide grains, and replace primary plagioclase; and Type II symplectites (of which there are 2 distinct categories) are comprised of anorthitic plagioclase with orthopyroxene ± amphibole vermicules, grow from primocryst olivine.

中文翻译：

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层状镁铁质侵入体中的微观结构和后期岩浆过程：来自加拿大魁北克省 Sept Iles 侵入体的辛方岩

替代性辛晶岩（两种或多种矿物的蠕虫状共生体）是层状火成岩侵入体的一个重要特征，记录了间隙液体和晶体之间后期反应的证据。它们在加拿大魁北克 564 Ma Sept Iles 层状侵入体的层状系列中很常见，分为三种类型：氧辛岩、“I 型”辛岩和“II 型”辛岩。含氧辛辉石由磁铁矿和斜方辉石组成，在橄榄石原晶上成核，通过橄榄石 + O2  斜方辉石 + 磁铁矿的反应形成；I 型辛长石（其中有 3 个不同的类别）由斜长石斜长石与辉石、角闪石或橄榄石蛭石组成，从初晶氧化物颗粒中生长，并取代原生斜长石；