摘要：AbstractWe present here for the first time, the Raman and infrared spectroscopic investigation of amphiboles from the World's deepest borehole, the Kola super-deep borehole, at the depth of 11.66 km. The Kola Super-deep borehole (SG-3) (henceforth referred as KSDB) is located in the northwest of the Kola Peninsula in the northern frame of the Pechenga structure, Russia. It was drilled in the north-eastern part of the Baltic Shield (69о5’N, 30о44’E) and reached a depth of 12.262 km. It has been drilled in the northern limb of the Pechenga geosyncline composed of rhythmically inter-bedded volcanogenic and tuffaceous-sedimentary strata extending to the NW at 300°–310° and dipping to SW at angles of 30°–50°. The SG-3 geological section is represented by two complexes – Proterozoic and Archaean. Amphibolite facies is dominant in the depth region from 6000 m to 12,000 m to the deepest.The Raman spectra of the sample reveal abundant presence of plagioclase and amphiboles. The most distinct Raman peak in this study indicates the tremolite-ferro-actinolite rich enrichment of the borehole samples at this depth corroborating earlier conventional petrographic studies.Graphical abstractDisplay OmittedHighlights•Abundant presence of plagioclase and amphiboles in the Kola super-deep borehole rock is observed.•Raman and infrared peaks indicate tremolite-ferro-actinolite rich enrichment at the depth of 11.66 km.•The Fe+2percentage and FWHM corroborate the presence of tremolite-ferro-actinolite series.
