In the Angara part of the Yenisei Ridge, a sequential section of the metapicritic–basalt sequence and overlying carbonate rocks of the Gorevskaya Formation is established. This section is considered as a single volcanic–sedimentary complex formed at the Late Mesoproterozoic–Early Neoproterozoic boundary in the riftogenic marginal–continental paleobasin in the southwestern Siberian Craton. It is proposed to introduce the metapicrite–basaltic sequence into the stratigraphic legend of the Shirokaya Group of the western Yenisei Ridge under the name “Nizhnerechinskaya Sequence”. In the studied section, metamorphosed picrobasalts and picrites predominate in the lower part of the Nizhnerechinskaya Sequence, while the middle and upper parts consist mainly of basalts containing Pb–Zn mineralization (Stepanovsky ore occurrence). At the contact with carbonate deposits of the Gorevskaya Formation, an alternation of volcanogenic rocks and terrigenous–carbonate sediments and metabasaltic sills are observed. The petrochemical and trace-element composition of metavolcanic rocks has much in common, which indicates the paragenetic relationship of rocks of this high-Mg rock association. All these rocks are enriched in Fe and Ti, while metabasalts and metagabbros show elevated alkalinity and P₂O₅ content. In terms of total alkalinity, metabasalt–picrobasalts deviate from the normal petrochemical series towards the subalkaline series, which correlates with their elevated Ti content. Basites enriched in alkalis, especially, in potassium and corresponding to trachybasalts are observed among them. The contents of incompatible trace elements clearly increase from picrites to basalts and reach maximum in trachybasalts, which show 1.5–3 times enrichment in high-field strength elements compared to the basalts. The paragenetic nature of the considered association is supported by the similar REE distribution patterns: (La/Yb)_n = 6–7 at Eu/Eu* = 0.9–1. The Late Mesoproterozoic–Early Neoproterozoic rifting of the Earth’s crust in the Angara region led to the opening of the marginal–continental sea basin, where basalt-picrite volcanism occurred simultaneously with accumulation of terrigenous–carbonate sediments, including ore–bearing (Pb–Zn) rocks of the Gorevskaya Formation, which host the Gorevskoye Pb–Zn deposit. The basin under consideration is interpreted as a relict rift-related paleobasin on the western margin of the Siberian craton, while the volcanic–sedimentary Nizhnerechinskaya Sequence is considered as the lower potential stratigraphic level of the base-metal mineralization in the Gorevsky ore field.

在叶尼塞山脊的安加拉部分，建立了变火山岩-玄武岩层序和戈列夫斯卡亚组上覆碳酸盐岩的连续剖面。该断层被认为是在西伯利亚克拉通西南裂谷生缘-陆古盆地中晚元古代—新元古代晚期边界形成的单一火山—沉积复合体。建议将玄武岩-玄武岩层序以“ Nizhnerechinskaya层序”的名称引入叶尼塞海脊西部Shirokaya群的地层传说中。在研究的部分中，变质的微玄武岩和微晶岩主要在Nizhnerechinskaya层序的下部，而中上部则主要由含有Pb-Zn矿化的玄武岩组成（Stepanovsky矿的发生）。在与Gorevskaya组的碳酸盐沉积物接触时，观察到火山成岩，陆源碳酸盐沉积物和准玄武质基岩的交替。准火山岩的岩石化学和微量元素组成有很多共同点，这表明这种高镁岩石组合具有岩石的共生关系。所有这些岩石都富含铁和钛，而玄武岩和偏辉石则显示出较高的碱度和磷₂ O ₅含量。就总碱度而言，偏玄武岩-偏高玄武岩盐从正常的石化系列向次碱性系列偏斜，这与它们的Ti含量升高有关。在其中观察到富含碱金属，尤其是钾和相应于菱形玄武岩的钡盐。不相容的痕量元素的含量明显地从苦味岩增加到玄武岩，并在次玄武岩中达到最大值，与玄武岩相比，高场强元素的富集度为1.5–3倍。相似的REE分布模式支持了所考虑的关联的共生性质：（La / Yb）_n在Eu / Eu * = 0.9-1时= 6-7。安加拉地区地壳的中元古代晚期至新元古代早期裂谷导致边缘-大陆海盆的开放，玄武岩-火山岩的火山活动与含碳酸盐（Pb-Zn）的陆源-碳酸盐沉积物的积累同时发生。 ）戈列夫斯卡亚组的岩石，该岩床蕴藏着戈列夫斯科耶Pb-Zn矿床。所考虑的盆地被认为是西伯利亚克拉通西缘的一个与裂谷裂谷有关的古盆地，而火山沉积的Nizhnerechinskaya层序被认为是戈列夫斯基矿场中贱金属矿化的潜在地层。