Geochemical features of rocks of the western Sikhote-Alin (Komsomolsky section) as indicators of the composition of the parental source rocks
The composition of the Late Mesozoic terrigenous rocks of the Komsomolsk reference section has been studied. According to the mineralogical-petrographic composition, the sandy rocks of the section belong to acidic greywacke and, partially, arkoses. The composition of the detrital material is dominat...
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| Format: | Article |
| Language: | Russian |
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Institute of Volcanology and Seismology FEB RAS
2022-07-01
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| Series: | Вестник Камчатской региональной ассоциации "Учебно-научный центр". Серия: Науки о Земле |
| Online Access: | http://www.kscnet.ru/journal/kraesc/article/view/713 |
| Summary: | The composition of the Late Mesozoic terrigenous rocks of the Komsomolsk reference section has been studied. According to the mineralogical-petrographic composition, the sandy rocks of the section belong to acidic greywacke and, partially, arkoses. The composition of the detrital material is dominated by sialic minerals originating from granitoids and granite-gneiss. According to the rock-forming oxide content (in %), sandstones (SiO2 — 69–77, Al2O3 — 11.99–15.9, Fe2O3 — 2.19–4.2) correspond to the acidic igneous rocks in the composition. In its turn, siltstones (SiO2 — 639–68%, Al2O3 — 14.79–17.0%, Fe2O3 — 4.09–6.7%) are located between medium and acid igneous rocks. According to the chemical classification sandstones belong to wackes and arkoses, and siltstones to shales and wackes. The total REE content in the studied sandstones ranges from 103 g/t to 162 g/t, in siltstones from 117 to 184 g/t. The relatively high ratios of light to heavy lanthanides in the studied rocks (LaN/YbN=7.0–12.0), as well as a fairly pronounced negative Eu anomaly, confirm the conclusion that the accumulation the Komsomolsk section was predominantly influenced by the eroded provenance composed of acidic igneous rocks. |
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| ISSN: | 1816-5524 1816-5532 |