The paper presents geochronological data and results of petrological modeling of the Monchegorsk and Monchetundra layered massifs. The U-Pb ID-TIMS zircon dating of norite from the marginal zone of Mt. Nittis yielded 2506 ± 7 Ma, which coincides with previous data on similar rocks from other areas. Based on the comparison of sections of the Monchegorsk and Kivakka massifs, the pre-erosion thickness of the Monchegorsk massif is estimated as 3700 m. Calculations using rocks of the marginal zone of the Monchegorsk intrusion at a pressure of 6.5–5.5 kbar showed that the melt in equilibrium with Ol contained SiO₂ ≤ 55 wt %, TiO₂ ≤ 0.50 wt %, and MgO ≤14 wt %. The temperature of the primary magma could be equal to 1390°C. At a lower pressure (below 6.5 kbar), the obtained melt becomes more siliceous. In the Monchegorsk intrusion, the composition of intratelluric olivine according to this model could vary within 88–92 mol % Fo. The content of intratelluric olivine in the melt, depending on pressure, could vary from 11 to 24 vol %. Magmas that formed the Monchegorsk intrusion and the layered series of the Monchetundra intrusion (hole 742) were derived from different sources.

本文介绍了 Monchegorsk 和 Monchetundra 层状地块的岩石学模型的年代学数据和结果。Mt. Nittis 边缘带的诺长岩 U-Pb ID-TIMS 锆石年龄为 2506 ± 7 Ma，这与之前其他地区类似岩石的数据一致。根据蒙切戈尔斯克地块和基瓦卡地块断面比较，蒙切戈尔斯克地块的侵蚀前厚度估计为 3700 m。使用压力为 6.5-5.5 kbar 的 Monchegorsk 侵入体边缘带岩石的计算表明，与Ol平衡的熔体含有 SiO ₂ ≤ 55 wt%，TiO ₂≤ 0.50 wt %，MgO ≤ 14 wt %。原生岩浆的温度可能等于 1390°C。在较低压力下（低于 6.5 kbar），获得的熔体变得更加硅质。在 Monchegorsk 侵入体中，根据该模型，地内橄榄石的组成可能在 88-92 mol% Fo范围内变化。熔体中的碲内橄榄石含量取决于压力，可以在 11 到 24 vol% 之间变化。形成 Monchegorsk 侵入体和 Monchetundra 侵入体（742 孔）的分层系列的岩浆来自不同的来源。