Abstract

In the Trollfjord–Rybachy–Kanin fault zone, the major convergent suture between the East European and West Arctic platforms, on the isthmus of Cape Vestnik located between the Sredny and Rybachy peninsulas, in the Riphean terrigenous sequence, massifs of disintegrated granitoids have been identified, primarily belonging to the Archean crystalline basement and which subsequently underwent tectonic extrusion to the upper horizons in the form of protrusions. Petrographic studies of disintegrated rocks from the Vestnik granitoid massif and the surrounding rocks indicate their high permeability and porosity in shattering zones. The positive Eu anomaly and decrease in content of light rare earth elements indicates the reducing nature of the fluids that affected disintegrated rocks, contributing to their formation under decompression conditions. The buried massifs of disintegrated granites may have reservoir properties. U–Pb and Sm–Nd isotopic studies of disintegrated plagiogranites with a model age of 2966 Ma has made it possible to correlate them with the rocks from the Murmansk block of the Baltic Shield. According to Sm–Nd data, the dolerite dike that cuts the plagiogranite massif has an age of 1333 ± 160 Ma (Middle Riphean) on pyrite and plagioclase, which corresponds to fragmentation of the basement at the initial continental rifting stage, which led to the formation of the White Sea paleorift system. East of Cape Vestnik, within the water area of the Barents Sea, a chain of linear–arched contrasting negative anomalies has been recorded in the gravity field. They are interpreted with high probability as reflections of the plate-shaped massifs of disintegrated granitoids included in the Riphean sedimentary sequence along the Trollfjord–Rybachy–Kanin shear zone, which may suggest a promising hydrocarbon potential of this zone under certain conditions.

中文翻译：

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东欧和西北极平台交界处的崩解花岗岩体地块：组成，年龄和烃潜力

摘要

在Trollfjord–Rybachy–Kanin断层带中，东欧和西北极平台之间的主要会聚缝合线位于Sredny和Rybachy半岛之间的Vestnik峡地带，位于Riphean陆源层序中，已确定了崩解花岗岩的断层，主要属于太古代的结晶基底，随后经历了构造的挤压作用，以突起的形式向上层地平线挤压。Vestnik花岗岩断层和周围岩石的崩解岩石学研究表明，它们在破碎带具有很高的渗透率和孔隙度。Eu正异常和轻稀土元素含量的减少表明影响崩解岩石的流体的还原性质，有助于其在减压条件下的形成。崩解花岗岩的埋藏地块可能具有储层性质。年龄为2966 Ma的崩解斜长花岗岩的U–Pb和Sm–Nd同位素研究使得将它们与波罗的海盾的摩尔曼斯克区块的岩石联系起来成为可能。根据Sm–Nd数据，切割斜长花岗岩岩体的白云石堤在黄铁矿和斜长石上的年龄为1333±160 Ma（中里菲安），这对应于初始大陆裂谷阶段基底的破碎，这导致了白海古构造的形成。在巴伦支海水域内维斯特尼克角以东，在重力场中记录了一系列线性拱形的对比负异常。