Tectonic and fluid reworking of deep-seated mafic intrusions in the orogenic belts often erase primary magmatic characteristics, and crystallization parameters of mafic melts enriched in volatiles remain an issue. This study presents new U-Pb geochronological data for zircons, mineral composition, whole-rock geochemistry and Sr-Nd isotopic data for Pechnoy ca. 2.2 Ga mafic layered sill in the central Belomorian province, Eastern Fennoscandian Shield. The Pechnoy intrusion comprises low-alumina, silica-undersaturated, Cl enriched mafic rocks depleted in HREE and HFSE with εNd values of -0.1–+1.5 and (Sr/Sr)2200 = 0.7024–0.7039. Field and petrological studies indicate that studied rocks preserved relicts of primary magmatic characteristics because it was encapsulated in host gabbronorite intrusion and avoided intensive fluid reworking during 1.8-2.0 Ga Lapland-Kola orogeny. Variations of mineral composition, major, and trace elements within intrusion originated via in situ fractional crystallization with dominated settling of clinopyroxene and plagioclase. Chlorine distribution within intrusion and in the host rocks inferred a magmatic origin Cl enrichment. High-Na scapolite is the main concentrator of the Cl in the rocks. The inclusions of scapolite in the relict magmatic plagioclase and higher Ca content relative to adjacent Na-rich plagioclase likely indicate early crystallization of high-Na scapolite. Trace element and isotopic characteristics of rocks indicate OIB and subduction modified SCLM signatures of their primary melts. A comparison of the available data for Pechnoy sill and coeval mafic sills in the Karelian Craton reveals a common mantle source for ca. 2.2. Ga igneous rocks in the Fennoscandian Shield although intrusions in the Belomorian province represent deeper levels of 2.2 Ga large igneous province plumbing system.

中文翻译：

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古元古代约。2.2 芬诺斯堪地盾东部贝洛莫里亚省的 Ga 高氯变辉长岩：起源和构造意义

造山带深层镁铁质侵入体的构造和流体改造往往会消除原生岩浆特征，而富含挥发物的镁铁质熔体的结晶参数仍然是一个问题。这项研究提供了新的锆石 U-Pb 年代学数据、矿物成分、全岩地球化学数据以及佩赫诺伊 (Pechnoy) 的 Sr-Nd 同位素数据。2.2 Ga 镁铁质层状基岩，位于 Belomorian 省中部、芬诺斯堪地盾东部。Pechnoy 岩体由低铝、硅不饱和、富含 Cl、贫 HREE 和 HFSE 的镁铁质岩石组成，εNd 值为 -0.1–+1.5，(Sr/Sr)2200 = 0.7024–0.7039。现场和岩石学研究表明，所研究的岩石保留了原生岩浆特征的遗迹，因为它被封装在宿主辉长岩侵入体中，并避免了 1.8-2.0 Ga 拉普兰-科拉造山运动期间的密集流体再加工。侵入岩中矿物成分、主量元素和微量元素的变化源于原位分步结晶，其中单斜辉石和斜长石的沉降占主导地位。侵入岩和主岩中的氯分布推断出岩浆起源的氯富集。高钠方柱石是岩石中Cl的主要富集体。残岩浆斜长石中的方沸石包裹体以及相对于邻近的富钠斜长石较高的钙含量可能表明高钠方沸石的早期结晶。岩石的微量元素和同位素特征表明其原始熔体的 OIB 和俯冲修正 SCLM 特征。对卡累利阿克拉通佩奇诺伊岩台和同时期镁铁质岩台的现有数据进行比较，揭示了大约 1000 亿年的共同地幔来源。2.2. 芬诺斯坎迪亚地盾中的 Ga 火成岩，尽管 Belomorian 省的侵入代表了 2.2 Ga 大型火成岩省管道系统的更深层次。