ILMENITE CONTENT OF THE DIFFERENT AGE LITHOFACIES FROM THE POROMIVSKE DEPOSIT PRODUCTIVE LAYER

• Дата: 2025
• Автори: Ганжа, О.А., Стародубець, К.М., Луньов, Є.С., Луньова, І.М.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Institute of Geological Sciences, NAS of Ukraine 2025
• Теми: lithofacies; ilmenite; Poromivske deposit; productive layer
• Онлайн доступ: http://geojournal.igs-nas.org.ua/article/view/335324
• Назва журналу: Geological journal

The ilmenite content of the different age lithofacies from Poromivske deposit (Volyn titanium region) was characterized. The main lithological rock types in the well sections were identified and characterized; lithofacies profiles within the deposit were constructed and analyzed; the connection between lithofacies features of the deposits and the distribution of ilmenite was investigated. The Poromivske field's productive layer is composed of weathering crust (69%), Paleocene-Eocene (27%), Neogene (2.3%) and Quaternary (1.8%) formations. The base of the productive layer is formed by the weathering crust, in which the ilmenite content ranges from 5.6 to 257.8 kg/m3, the average is 61.1 kg/m3. The ilmenite content almost always increases towards the upper parts of the weathering crust, with the highest values being typical for the kaolinite-mica zone. It has been established that the placer formation within the Poromivske ilmenite deposit is due to a combination of a number of geological, morphostructural and climatic factors that contributed to the formation of ilmenite placers, in particular in Paleogene and Mesozoic-Cenozoic sediments. The formation of the placers involved geomorphic processes of different ages that caused the transfer and accumulation of ilmenite at different stratigraphic levels. Despite the higher ilmenite content in the Paleocene-Eocene alluvial-deluvial sediments (from 5 to 636.6 kg/m3, average 74.8 kg/m3), their share in the productive layer is 27%, which is due to their lower thickness compared to the weathering crust. In contrast to the eluvium, the ilmenite content increases towards the bottom of the section and is confined to the bends and floodplain depressions of the ancient valley. Secondary kaolins are the most enriched in ilmenite among the rocks of this stratum. Neogene continental (Lower-Middle Miocene) and coastal-marine (Miocene-Pliocene) sediments are limited in distribution over the Poromivske field area and have lower ilmenite content (45 kg/m3 on average) compared to weathering crust and Paleocene-Eocene sediments, which is why they have a small share in the productive layer. Quaternary formations are characterized by the greatest diversity of facies types of sediments (lake, alluvial, alluvial-deluvial, glacial submorain, moraine, and supramoraine sediments of the Dnipro climatolithic). The average ilmenite content in them is 68.20 kg/m3. Thus, the ore layer of the Poromivka ilmenite deposit is composed of 13.7% sands of various grains, 2.0% clay, 15.1% secondary kaolins, 57.7% primary kaolins, and 11.5% micas.