MINERALOGICAL CHARACTERISTICS OF THE POROMIVKA EXOGENIC ILMENITE DEPOSIT, VOLYN TITANIUM-BEARING REGION

The results of ilmenite research from the Poromivka exogenic deposit, one of the promising sites in the Volyn titanium-bearing region, are presented. The study was conducted using electron probe microanalysis (EPMA) and structural-lithological modeling methods. The main ore mineral of the deposit is ilmenite. Associated ore minerals include zircon, rutile, apatite, pyrite, marcasite, and others. In the productive layer of the Poromivka deposit, the weathering crust of crystalline rocks occupies approximately 69%, undifferentiated Paleocene-Eocene formations account for about 26.9%, Neogene formations for 2.3%, and Quaternary formations for 1.8%. The average ilmenite content in the weathering crust is 70.02 kg/m3, and in the Paleocene-Eocene formations range between 70 and 80 kg/m3. The ilmenite is rutilized. Three stages of ilmenite transformation have been identified within the formations of the productive layer: 1). Ilmenite from bedrock with no signs of leucoxenization, almost unaltered (kaolinite–hydromica zone of the weathering crust); 2). Ilmenite with a higher degree of alteration and signs of leucoxenization (kaolinite zone of the weathering crust and Paleocene–Eocene formations); 3). Ilmenite in a nearly unaltered state or with only slight alteration (Miocene, Pliocene and Quaternary). Rutilization occurs in three main forms: isolated rutile grains, rutile along fractures, and rutile developed in the outer zones of ilmenite grains. According to EPMA data, inclusions of quartz, rutile, apatite, magnetite, sillimanite, and garnet were identified within ilmenite. The overall mineral composition of the inclusions reflects the evolution of the geochemical environment during mineral formation at the Poromivka deposit.